17th June 2024

African Trypanosomiasis

African trypanosomiasis, or African sleeping sickness, is caused by the protozoal species Trypanosoma brucei. West African trypanosomiasis is caused by the subspecies Trypanosoma brucei gambiense, with the rarer East African trypanosomiasis being caused by the subspecies Trypanosoma brucei rhodesiense. Spread by the tsetse fly, these diseases are fatal unless treated. T. gambiense infection presents with an early stage consisting of low-grade fever, joint pain, and lymphadenopathy. Posterior cervical lymphadenopathy may be present. This is known as Winterbottom’s sign, after the physician and abolitionist who noted its prognostic use by slave traders. The latter stage involves central nervous system (CNS) infection, with personality change, disturbance of circadian rhythm, and death within months if left untreated. T. rhodesiense infection follows a more acute course. The initial stage is more severe and more likely to result in death, with pericarditis, myocarditis, and severe anaemia common. The CNS stage also appears more quickly and follows a rapid course to fatality if left untreated. Blood films, bone marrow biopsies and lymph node biopsies can be useful in diagnosis. Suramin can be used to treat both early-stage variants, though pentamidine is often used for T. gambiense disease. Neither drug penetrates the CNS and therefore, a lumbar puncture is necessary to diagnose late-stage disease. Melarsoprol, which can be used for the late stage of both diseases, carries a significant risk of encephalopathy and death. Eflornithine, which is safer, can only be used for late-stage T. gambiense disease.