Tsetse fly — DTM&H MCQ
Instant feedback + full explanation. One question, done properly.
Educational content. Not a substitute for clinical judgement or local policy.
Reveal the answer and explanation
Correct answer: A — Glossina tsetse fly
The correct answer is A, Glossina tsetse fly. This case describes East African (rhodesiense) sleeping sickness, acquired in a savannah woodland game park setting in Zambia, which is the classic ecological niche of the tsetse fly. Tsetse flies are large, day-biting flies whose bite is often painful and can be followed by a local inflamed papule that evolves into the trypanosomal chancre described here. The tsetse fly is both vector and biological intermediate host, as the trypanosome undergoes obligatory development in its gut and salivary glands before transmission, a process UK travel health guidance highlights when advising bite avoidance in rural woodland and savannah areas frequented by safari travellers. Why the other options are wrong: E. Triatomine bug: This is the vector for Trypanosoma cruzi (Chagas disease) in the Americas, transmitted by faecal contamination of a bite wound rather than saliva, and is not found in Zambia. B. Chrysops deer fly: This transmits Loa loa (loiasis) in West and Central African rainforest, not trypanosomiasis, and does not produce a chancre. C. Culex mosquito: This transmits lymphatic filariasis (Wuchereria bancrofti) and some arboviruses, not trypanosomes. D. Female Anopheles mosquito: This is the vector for malaria (Plasmodium species), which does not cause a chancre and is diagnosed by blood film showing intraerythrocytic parasites, not extracellular trypanosomes. Key point: A painful bite chancre plus trypanosomes on blood film in a savannah game park exposure in Africa points to tsetse fly (Glossina) transmitted sleeping sickness.
Reference: NaTHNaC TravelHealthPro, Trypanosomiasis, https://travelhealthpro.org.uk/disease/214/trypanosomiasis