TREMATODES -1Schistosoma (Blood Flukes) Doç.Dr.Hrisi BAHAR Class Trematoda (Flukes) General characteristics ►They are dorsoventrally flattened with an oval to lancet shape. ► Others have different shapes such as the threadlike.
Download ReportTranscript TREMATODES -1Schistosoma (Blood Flukes) Doç.Dr.Hrisi BAHAR Class Trematoda (Flukes) General characteristics ►They are dorsoventrally flattened with an oval to lancet shape. ► Others have different shapes such as the threadlike.
Slide 1
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 2
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 3
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 4
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 5
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 6
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 7
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 8
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 9
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 10
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 11
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 12
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 13
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 14
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 15
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 16
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 17
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 18
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 19
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 20
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 21
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 22
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 23
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 24
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 25
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 26
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 27
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 28
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 29
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 30
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 31
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 2
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 3
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 4
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 5
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 6
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 7
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 8
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 9
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 10
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 11
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 12
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 13
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 14
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 15
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 16
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 17
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 18
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 19
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 20
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 21
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 22
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 23
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 24
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 25
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 26
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 27
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 28
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 29
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 30
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.
Slide 31
TREMATODES
-1Schistosoma
(Blood Flukes)
Doç.Dr.Hrisi BAHAR
Class Trematoda
(Flukes)
General characteristics
►They are dorsoventrally flattened with an
oval to lancet shape.
► Others have different shapes such as the
threadlike schistosomes.
Class Trematoda
• Most species are hermaphroditic.
• Snails are the first intermediate hosts.
• Some species require arthropods or fish
as a second intermediate hosts
Class Trematoda
Schistosoma (Blood Flukes)
► The causative agent ofschistosomiasis or
bilharziosis.
► One of the most frequent tropical
diseases
► Occurrence depends on the presence
of suitable intermediate hosts
Schistosoma (Blood Flukes)
► German physician Th. Bilharz, discovered
Schistosoma hematobium in human blood
vessels in 1851.
► Occurs endemically in tropical and subtropical
countries of Africa, South America, and Asia .
► The number of persons infected is estimated as 240
million worldwide (WHO 2011)
Schistosoma (Blood Flukes)
► Human infections result from contact with
water (freshwater) and Schistosoma cercariae
► Schistosoma hematobium causes urinary
schistosomiasis.
►S. mansoni, S. japonicum,S. intercalatum, and
S. mekongi are the causative agents of
intestinal schistosomiasis and other forms of
the disease.
Schistosoma (Blood Flukes)
Morphology and life cycle
► The relatively thick male forms a
tegumental fold in which the threadlike
female is enclosed.
► The adult parasites live in the lumen of veins.
Schistosoma (Blood Flukes)
Schistosoma (Blood Flukes)
1-Sexually mature Schistosoma females lay
about 100–3500 eggs a day containing an
immature miracidium.
2-The miracidium within six to 10 days,
remains viable for about three weeks
Schistosoma (Blood Flukes)
► At the site of their deposition, the eggs
lie in chainlike rows within small veins.
► Some penetrate through the vascular
wall and surrounding tissue to reach the
lumen of the urinary bladder or intestine.
Schistosoma (Blood Flukes)
► Enzymes produced by the miracidium
cause a granuloma formation .
►The eggs are shed by the definitive host
in stool or urine .
Schistosoma (Blood Flukes)
► If the eggs are deposited into fresh
water, the miracidia hatch from the
eggshell and search a suitable
intermediate host.
►Freshwater snails serve as intermediate
hosts in which miracidia reproduce asexually,
producing mother and daughter sporocysts
Schistosoma (Blood Flukes)
The cercariae upon contact with a human host,
Enzyme secretion and vigorous movements
enable them to penetrate the skin or less
frequently the mucosa when ingested with
drinking water.
Shistosoma miracidium
Schistosoma (Blood Flukes)
• During the infection process, the
cercaria loses its tail, sheds the surface
glycocalyx, forms a new tegument, and
transforms into the schistosomulum.
Migration of Schistosomes in
the Human Body
• Infection
Schistosomula penetrates subcutaneous
tissues, find venous capillaries or lymph
vessels, migrate through the venous
circulatory system into the right ventricle
of the heart and the lungs.
Migration of Schistosomes in
the Human Body
It travels hematogenously into the
intrahepatic portal vein branches where
development into adult worms takes place
as wells as male-female pairing just prior
to sexual maturity.
Pathogenesis and clinical
manifestations
The infection can be divided into the
following phases:
1-Penetration phase :penetration of
cercariae into the skin, either without
reaction or—especially in cases of
repeated exposure—with skin lesions
(erythema, papules), which disappear
within a few days.
Pathogenesis and clinical
manifestations
2-Acute phase, about two to ten weeks after a
severe initial infection,the symptoms like,
fever, headache, limb pains, urticaria,bronchitis,
upper abdominal pain, swelling of the liver and
spleen, lymph nodes, intestinal disturbances, and
eosinophilia (=Katayama syndrome) appear .
Pathogenesis and clinical
manifestations
Due to release of Schistosoma antigens,
the serum antibody levels (IgM, IgG,
IgA)rise rapidly and immune
complexes are formed that can
cause renal glomerulopathies.
Pathogenesis and clinical
manifestations
3-Chronic phase: The most significant
phase in pathogenic terms begins after an
incubation period of about two months with
oviposition by the Schistosoma females.
Pathogenesis and clinical
manifestations
The miracidia grow in the egg which
remain viable for about three weeks,
produce antigens which are secreted
through the eggshell into the tissue.
Pathogenesis and clinical
manifestations
After antigenic stimulation, T lymphocytes
secrete cytokines which contribute to
produce granulomatous reaction and
”pseudotubercles” above all
macrophages, neutrophilic and eosinophilic
granulocytes, as well as fibroblasts and
aggregate around eggs.
Pathogenesis and clinical
manifestations
Granulomatous proliferations protrude into
the lumen of the urinary bladder or
intestine.
The granulomas are replaced by connective
tissue, producing more and more fibrous
changes and scarring.
Clinical manifestation
Clinical manifestation
• The main forms of schistosomiasis are
differentiated according to the localization
of the lesions:
1-Urinary schistosomiasis (urinary bilharziosis)
2-Intestinal schistosomiasis (intestinal bilharziosis)
3-Hepatosplenic schistosomiasis
4-Cerebral and pulmonary schistosomiasis
5-Cercarial dermatitis
Schistosoma (Blood Flukes)
Diagnosis.
1-The eggs can be detected in stool specimens
or in urine sediment. The eggs can also be
found in intestinal or urinary bladder wall
biopsies.
2-Immunodiagnostic methods are particularly
useful for detecting infections before egg
excretion begins.
(important for travelers returning from tropical regions).
Schistosoma (Blood Flukes)
Detection of microhematuria with test strips
is an important diagnostic tool in bladder
schistosomiasis.
Clinical examination with portable ultrasonic
imaging equipment has proved to be a
highly sensitive method of detecting lesions
in the liver and urogenital tract in
epidemiological studies.
Schistosoma (Blood Flukes)
Therapy.
The drug of choice for treatment of
schistosomiaisi is praziquantel,which is
highly effective against all Schistosoma
species and is well tolerated.