Which parasite is associated with African sleeping sickness transmitted by the tsetse fly?

Which parasite is associated with African sleeping sickness transmitted by the tsetse fly?

• A. Trypanosoma brucei
• B. Naegleria fowleri
• C. Toxoplasma gondii
• D. Giardia lamblia

Answer: (A)

African sleeping sickness is caused by a flagellated protozoan that is transmitted by the bite of the tsetse fly. The parasite responsible is Trypanosoma brucei. In humans, it circulates in the blood and eventually invades the central nervous system, leading to fever, lymphadenopathy, and progressive sleepiness or coma as CNS involvement develops. A key feature is antigenic variation of the parasite’s surface coat, which lets it dodge the immune response and causes relapsing fevers as the immune system repeatedly fights off new variants. Transmission happens when the tsetse fly acquires the parasite from an infected host and then injects infectious forms into a new host during a bite. The disease has two main African forms caused by different subspecies, but both arise from the same organism. Other parasites listed cause different problems: Naegleria fowleri causes fatal brain infection after swimming in warm water, Toxoplasma gondii is associated with cat exposure and undercooked meat, and Giardia lamblia causes giardiasis from contaminated water.

African sleeping sickness is caused by a flagellated protozoan that is transmitted by the bite of the tsetse fly. The parasite responsible is Trypanosoma brucei. In humans, it circulates in the blood and eventually invades the central nervous system, leading to fever, lymphadenopathy, and progressive sleepiness or coma as CNS involvement develops. A key feature is antigenic variation of the parasite’s surface coat, which lets it dodge the immune response and causes relapsing fevers as the immune system repeatedly fights off new variants. Transmission happens when the tsetse fly acquires the parasite from an infected host and then injects infectious forms into a new host during a bite. The disease has two main African forms caused by different subspecies, but both arise from the same organism. Other parasites listed cause different problems: Naegleria fowleri causes fatal brain infection after swimming in warm water, Toxoplasma gondii is associated with cat exposure and undercooked meat, and Giardia lamblia causes giardiasis from contaminated water.