Transcript Quiz 1 - Matthew Bolek

Fascioloides magna “Giant Deer Fluke”
• Different behavior and
pathology in different
hosts.
Fascioloides magna “Giant Deer Fluke”
• Deer and Elk (normal
hosts)—Liver
migration, then
matures in thin-walled
fibrous cysts connected
with bile ducts. (Well
tolerated; eggs shed in
feces).
Fascioloides magna “Giant Deer Fluke”
• Cattle, bison and
swine—Liver
migration, then
encapsulation in thickwalled, closed cysts
and no eggs are shed!
Fascioloides magna “Giant Deer Fluke”
• Sheep and goats:
extensive,
uninterrupted hepatic
migration with out
encapsulation; usually
fatal; 1 fluke can kill a
sheep or goat!
Pathology
• Pathology in C. sinensis and D. dendriticum:
distended bile ducts and erosion of
epithelium lining, but no secondary
pathology like in F. hepatica!
Treatment
• Preziquantel (except for F. hepatica).
• Rafoxanide: is the drug of choice for F.
hepatica!
Diagnosis
• Look for eggs in feces!
• But hard to diagnose (why?).
• SPURIOUS INFECTIONS!
Aquatic Vegetation
Water Chestnuts
Pickled Fish
Digestive Tract Trematodes
Fasciolopsis buski
• Order:
Echinostomatiformes
• Humans, pigs
• Orient
• Large (7.5 cm)
• Life cycle similar to
Fasciola
Pathology and Symptoms
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Severity depends on worm burden
Irritation
Excess mucous secretion
Ulceration, hemorrhage, Abscess
Obstruction
Chronic diarrhea
Sensitization to worm metabolites
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Leukocytosis
Anemia
Eosinophilia
Nausea/diarrhea
Edema of face and intestinal wall
Death
Treatment
• Praziquantel
Epidemiology
• Who gets infected?
• Rural to semi-urban areas
• School age children
– Prevalence
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57% China
25% Taiwan
50% Bangladesh
60% India
10% Thailand
Epidemiology
• How do you get fasciolopsiasis?
• Ingest metacercariae
• Commercially raised aquatic plants
Water chestnut
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Water caltrop
Water hyacinth
Water lotus
Water lily
Watercress
Epidemiology
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Lack of regulation on food industry
Food preparation
Sanitation (sewage)
Night soil
Pigs
– Habitat
– Food
Digestive Tract Trematodes
• FAMILY ECHINOSTOMATIDAE intestinal parasites recognized by their
anterior collar of spines.
• Echinostoma revolutum - Cosmopolitan
parasite of birds and mammals– shows low
host specificity
• Human cases?
Morphology of Adult Echinostoma
revolutum
Adults are elongate, up to
an inch in length.
Characteristic structure
is: their circumoral collar
of spines arranged in two
rows.
37 spines in E. revolutum.
Internal organs are
distinct and easy to
identify.
Morphology of Adult Echinostoma
revolutum
Collar of spines around oral sucker
uterus
Vitellaria
Testes
Mehlis’ gland Ovary
Life Cycle of Echinostoma
revolutum
Parasite shows low host
specificity throughout
cycle
1. Adults occur in birds
and mammals.
2. Eggs are released via
the feces into an aquatic
habitat.
3. Miracidia hatch, swim
to snail, and penetrate.
Life Cycle of Echinostoma
revolutum
4. Sporocysts and rediae
occur within snail.
Cercariae are released.
5. Cercariae penetrate
(2nd intermediate hosts)
and encyst as
metacercariae.
6. Definitive host is
infected by ingesting 2nd
intermediate
host, metacercariae
excyst in stomach, and
adults mature
in small intestine.
Order Plagiorchiformes
• Family Troglotrematidae: these are oval
thick flukes with a spiny tegument and
dense vitellaria.
• Parasites of lungs, intestine, nasal passages,
cranial cavities, and various ectopic
locations.
Nanophyetus salmincola
Fish Eating
Mammal
(Birds)
Salmonid fish
Freshwater
Snail
Nanophyetus salmincola
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Northwest N. America
Northeast Asia
Crypts of the small intestine
Human infections
– 98% prevalence in Siberian
villages
• Pathology
Nanophyetus salmincola
• Salmon poisoning
• Highly pathogenic
• Neorickettsia helminthoeca
– Rickettsia
– Intracellular bacterium
– Typhus
• Nanophyetus salmincola is a
vector for Neorickettsia
helminthoeca.
Nanophyetus salmincola
• Disease
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High Fever
Edema of face
Vomiting
Diarrhea
Death in 10 days to 2 weeks.
Lung Flukes
• Paragonimus
• bronchiolar lumen
and peribronchial
tissues
• Antigenic
• Become
encapsulated
– granuloma
Paragonimiasis
• Paragonimus
• 7 species in Asia, SubSaharan Africa, Central
and South America
• Paragonimus westermani
Life cycle of Paragonimus
Paragonimus cercaria
Paragonimus westermani
• 1st Int. Host
– Freshwater snails
– Streams
– Rice paddies
Melanoides tuberculata
Paragonimus westermani
• 2nd Int. Hosts:
– Potamon
• Rice Paddies
– Eriocheir
• Streams
• Larvae develop
in brackish
water
Paragonimus kellicotti
• Crayfish serve as
2nd IH in North
America.
• Metacercariae
are found in the
heart.
Paragonimus
• A number of birds and
mammals are know to
serve as PH!
• Guinea pigs are known
to serve as
PARATENIC HOSTS
for Paraganimus spp.
in South America!