African trypanosomiasis

African trypanosomiasis, also known as sleeping sickness, is an infectious parasitic disease caused by protozoan parasites of the species Trypanosoma brucei, transmitted to humans through the bite of infected tsetse flies (Glossina species). There are two forms of the disease: West African trypanosomiasis (caused by Trypanosoma brucei gambiense, ICD-10 B56.0), which accounts for over 95% of reported cases and follows a chronic course, and East African trypanosomiasis (caused by Trypanosoma brucei rhodesiense, ICD-10 B56.1), which presents as a more acute and rapidly progressive illness. The disease is endemic to sub-Saharan Africa, restricted to areas where tsetse flies are found. The disease progresses through two stages. In the first (hemolymphatic) stage, the parasites multiply in the blood, lymph, and subcutaneous tissues, causing symptoms such as intermittent fever, headache, joint pain, lymphadenopathy (notably posterior cervical lymph node swelling known as Winterbottom's sign in the gambiense form), pruritus, and a characteristic chancre at the site of the tsetse fly bite. In the second (meningoencephalitic) stage, the parasites cross the blood-brain barrier and invade the central nervous system, leading to progressive neurological and psychiatric disturbances including sleep cycle disruption (the hallmark feature giving the disease its common name), confusion, behavioral changes, sensory disturbances, poor coordination, and eventually coma and death if left untreated. Treatment depends on the disease stage and the infecting subspecies. For the first stage, pentamidine (gambiense form) and suramin (rhodesiense form) are used. For the second stage, traditional treatments included melarsoprol (an arsenic-based drug with significant toxicity) and eflornithine. A major advance has been the introduction of nifurtimox-eflornithine combination therapy (NECT) for second-stage gambiense disease. More recently, fexinidazole became the first all-oral treatment approved for both stages of gambiense sleeping sickness, representing a significant improvement in disease management. Acoziborole is under development as a potential single-dose oral treatment. Due to sustained control efforts, the number of reported cases has declined dramatically, and the WHO has targeted elimination of gambiense sleeping sickness as a public health problem.

Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.

Common questions about African trypanosomiasis