Which insect is responsible for the spread of African Trypanosomiasis (sleeping sickness)?

• A. Mosquito
• B. House fly
• C. Tsetse fly
• D. Cockroach

Answer: (C)

The spread of sleeping sickness depends on a biological vector that supports the parasite’s development. The disease is caused by Trypanosoma brucei, and transmission occurs when a tsetse fly bites an infected host, the parasite continues its life cycle inside the fly, and a later bite from the same or another tsetse fly injects the infectious form into a new person. This reliance on the parasite’s development inside the insect makes the tsetse fly the essential spreader.

Other insects, like mosquitoes, house flies, or cockroaches, do not biologically transmit Trypanosoma brucei to humans. They may carry pathogens on their bodies or surfaces, but they don’t support the parasite’s life cycle to the infectious stage that’s needed for transmission to people.