Transcript Trypanosoma brucie gambiense Trisha Patel

Trypanosoma brucie
gambiense
Trisha Patel
“From the beginning of Arab and European influence in the hinterland of tropical
Africa, trypanosomiasis of man and animals has curbed the realization of human
ambitions and the mobilization of the continent’s vast resources.”
--Herbert S. Gasser
WEST AFRICAN SLEEPING
SICKNESS
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Found in western and central Africa
Transmitted human to human via tsetse fly vector
Slow onset of symptoms
Two stages:
First stage- Before crossing the blood-brain barrier
Second stage- After crossing the blood-brain barrier and entering the
Central Nervous System
DISCOVERY
The first documented case of Trypanasoma brucei was in
1902 by R.M. Forde. In The Journal of Tropical Medicine,
Forde records his account of a 42 year-old European male
colonialist who came to him in May 1901 in Gambia Colony.
The patient complained about having a fever and malaise.
Forde presumed the gentleman to have malaria and
therefore gave him anti-malarial medication. After days the
condition had remained the same. A blood sample from the
patient was taken and it showed no malarial parasites.
Later, Dutton, another physician from the Liverpool School
of Tropical Medicine, identified the parasite within the
patient’s blood as Trypanasoma brucei. Due to the location
of the parasite within the patient, it is assume that the
species was of T.b. gambiense.
TIMELINE
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14th Century: First described case in Mali
1896- 1906: First major recorded endemic
1902: R.M. Forde & Dutton identified one
causative agent of the sleeping disease
1903: Castellani working in Uganda observed
the parasite in the cerebrospinal fluid
of one of his patients
Sir David Bruce
1903: Sir David Bruce recognized Tsetse fly as vector
1906: Ayres Kopke introduced Atoxyl, an arsenic compound, as a
treatment
1920: Second major recorded endemic (first noted by Jamrot, a
colonel for the French army)
1970- now: Third major recorded endemic
1984: The World Health Organization (WHO) launched a program
to control trypanosomiasis
MAJOR ENDEMICS
Three Major Endemics:
• 1896 through 1906 (mostly in Uganda and the Congo Basin)
• 1920 (several African countries)
- Contained due to screening of millions of people at risk
- The disease has practically disappeared from 1960-1965
- Surveillance was relaxed causing a relapse
• 1970-now
- With the help of the World Health Organization, national control
programs, and nongovernmental organizations efforts to
control the spread have been implemented
PREVELANCE
Thirty-six countries in equatorial Africa could be affected, including 22 of the world's most
underdeveloped countries.
In the United States, 31 cases of trypanosomiasis have been reported; mostly Eastern
Sleeping Sickness.
In 1998, almost 40,000 cases were reported but about 300,000-500,000 went undiagnosed
In the Congo, more people die from sleeping sickness than from AIDS.
Fifty-five to 60 million people in equatorial Africa that are exposed to the risk of a bite from
the tsetse fly.
The number of cases have decreased. From 1998 to now, reported cases feel from 37,991 to
17,616.
It costs about a thousand dollars to treat a victim of the parasite.
Recently, in the Democratic Republic of Congo, Angola and Southern Sudan, prevalence has
reached 50%. This is greater than those infected with HIV/AIDS in these areas.
PREVANECE CONTINUED
SPREAD
 Transmitted by Tsetse fly
 War
 A pregnant women pass it to her
fetus (rare)
 Through a blood transfusion (rare)
 Homosexual males (very rare)
 The migration of people
ENVIRONMENTAL CHANGES
Glossina papalis tsetse fly - lives near
vegetation associated with drainage lines,
rivers, and other permanent bodies of water
Removal of waterways are ineffective since:
• They are also habitats for other insects
and animals
• They are a source of water for people
• Vegetation around these areas need water
Sanitation of waterways will not effect the
spread of the organism.
TREATMENT
First stage treatments
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Pentamidine:
Discovered in around 1941
Highly effective
Few side-effects; usually tolerable
Second stage treatments
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Melarsoprol:
Discovered in 1949
Arsenic base
Many side-effects including
enchephalopathy, myocarditis, renal
damage, peripheral neuropathy, etc.
Fatal (3-10%)
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Eflornithine:
Also known as “the resurrection drug”
Registered in 1990
Less toxic than melarsoprol
Regime is strict and difficult to apply
Costly
PREVENTION
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Wear khaki or olive colored clothing
Wear thick clothing
Use insect repellant
Use bed netting when sleeping
Inspect vehicles for tsetse flies before
entering
Do not ride in the back of jeeps, pickup
trucks or other open vehicles
Avoid bushes (tsetse fly is less active
during the hottest time of the day and
rests in bushes—it will bite if disturbed)
Avoid thick shrubbery and trees by rivers
and waterholes
Test blood during transfusions
SOURCES
“African Trypanosomiasis.” African Sleeping Sickness. 22 May, 2001. 13 November, 2006.
<http://www.stanford.edu/class/humbio103/ParaSites2001/trypanosomiasis/trypano.htm>.
“Background to Trypanosoma brucei gambeinse genome project.” 13 November, 2006.
<http://www.bio.bris.ac.uk/research/molpar/TBG.pdf#search='Trypanosoma%20brucei%20gambiense%20%20%20Disc
overy’>.
“Behind the Frieze.” Sir David Bruce. London School of Hygiene and Tropical Medicine. 1 August, 2005. 16 November, 2006.
<http://www.lshtm.ac.uk/library/archives/bruce.html>.
“Google Image Search.”
19 November, 2006. <http://images.google.com/imghp?ie=UTF-8&oe=UTF-8&hl=en&tab=wi&q=>.
“Reanalyzing the 1900–1920 Sleeping Sickness Epidemic in Uganda.” Center of Disease Control. 12 April, 2004. 16
November, 2006. <http://www.cdc.gov/ncidod/EID/vol10no4/02-0626.htm>.
“Sleeping Sickness.” Wikimedia Foundation, Inc. 15 November, 2006. 16 November, 2006.
<http://en.wikipedia.org/wiki/Sleeping_sickness#Treatment>.
“Trypanosomiasis.” Microbiology @ Leicester. 19 October, 2004. 13 November, 2006.
<http://www-micro.msb.le.ac.uk/224/Trypano.html>.
“Trypanosomiasis/Sleeping Sickness.” Medindia Health Network Pvt Ltd. 13 November, 2006. 13 November, 2006.
<http://www.medindia.net/patients/patientinfo/trypanosomiasis_Clinical.htm>.
Watson, Debra. “War, famine and now pestilence.” Sleeping sickness ravages Central Africa. International Committee of the
Fourth International. 5 September, 1998. 19 November, 2006.
<http://www.wsws.org/news/1998/sep1998/slep-s05.shtml>.