African Sleeping Sickness

Trypansoma brucei sp. in a thin blood smear, dividingA recent post looked at the need for an improvement in the treatment of African Trypanosomiasis, also known as sleeping sickness.   

Basics:

Also known as “African Sleeping Sickness”. This is a protozoal disease from the famous Tsetse fly’s (Glossina species) bite. Two main species exist, Trypanosoma Brucei Gambiense (West Africa) and T. B. Rhodesiense (East Africa). T.B. Gambiense can be an indolent disease for several years. T.B Rhodesiense is fatal in weeks to a month. Both are fatal, unless treated.  This disease affects 300,000 to 500,000 people, as of 2006. Symptoms include fever, a painful blister/chancre at bite site, lymphadenopathy (lymph node swelling) are common. As the illness progresses and the trypanosomes cross the blood-brain barrier, sleep disturbances and mental status changes are seen.

 Location:

Trypanosoma Brucei Gambiense is found is Western Africa, in areas where Glossinia (tsetse) species live. T.B. Rhodsiense is found in scattered spots of Eastern Africa and more associate with sylvatic cycles involving wild deer and range animals.

Transmission/ Incubation:

Acquired from the bite of an infected tsetse fly. T. Rhodesiense can become symptomatic is a few days to weeks, while T. Gambiense can take months to years before presentation.

Prevention:

Avoidance of bites from infected Glossina fly species, reduction of species

Diagnosis:

Demonstration of trypanosomes in blood, lymph or CSF (the fluid around the brain and spine) is gold standard. Centrifugation is generally needed for proper identification. A rapid reagent card agglutination test for T.B. Gambiense exists (CATT). ELISA can also be used to diagnose. Diagnosis cannot be based on symptoms alone.

Treatment:

Based on which species causes the infection. Early treatment has a high cure rate. Pentamadine, melarsoprol, eflornithine, suramin and nifurtimox are the main drugs used to treat this. Pentamiadine is used for early stage T. B. Gambiense and Suramin for early stage T.B. Rhodesiense. Late stages of both diseases (including neurological forms) can be treated with melarsoprol or eflornithine. Caution giving these last two drugs as the side effect of encephalopathy can be fatal.

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