Human African trypanosomiasis — DTM&H MCQ

Correct answer: B — West African human African trypanosomiasis

The correct answer is B, West African human African trypanosomiasis (Trypanosoma brucei gambiense infection). This diagnosis fits a patient from the Democratic Republic of the Congo, an endemic focus, with a months-long chronic illness combining fever, pruritus, headache and neuropsychiatric sleep-wake disturbance (daytime somnolence with night-time insomnia), which reflects meningoencephalitic (second-stage) disease. The posterior cervical lymphadenopathy described is the classic Winterbottom's sign, most typical of T. b. gambiense rather than the East African (rhodesiense) form. This chronic, indolent tempo over months, rather than days, together with the sleep cycle reversal, is the discriminating clue that points away from other febrile tropical illnesses. Why the other options are wrong: D. Neurocysticercosis: causes seizures and focal neurological signs from cystic brain lesions, not a chronic febrile pruritic illness with lymphadenopathy or sleep-wake reversal. A. Acute falciparum malaria: presents acutely over days with cyclical fevers and can be rapidly fatal; it does not cause a months-long course, pruritus, or posterior cervical lymphadenopathy. C. Visceral leishmaniasis: causes prolonged fever with marked hepatosplenomegaly, pancytopenia and weight loss, but not the characteristic sleep-cycle disturbance or Winterbottom's sign. E. Scrub typhus: is a rickettsial infection of Asia-Pacific, presenting with eschar, rash and acute fever over one to two weeks, not months, and is not endemic to DRC. Key point: chronic fever with pruritus, posterior cervical lymphadenopathy (Winterbottom's sign) and reversed sleep-wake cycle in a patient from Central/West Africa signals second-stage T. b. gambiense sleeping sickness.

Reference: StatPearls (NCBI Bookshelf), Human African Trypanosomiasis (Sleeping Sickness), updated 2023, https://www.ncbi.nlm.nih.gov/books/NBK535413/