Which organism is primarily responsible for causing African sleeping sickness?

Trypanosoma brucei is the organism primarily responsible for African sleeping sickness, also known as human African trypanosomiasis. This disease is transmitted to humans through the bite of the tsetse fly, which is found in certain regions of sub-Saharan Africa.

T. brucei exists in two forms that cause the disease: Trypanosoma brucei gambiense, which causes the chronic form, and Trypanosoma brucei rhodesiense, which leads to the acute form. The symptoms of African sleeping sickness include fever, headaches, joint pains, and itching in the early stages, followed by neurological problems as the disease progresses, leading to confusion, changes in behavior, and sleep cycle disturbances—thus the name "sleeping sickness."

This specific parasitic organism is distinct from the others listed. For instance, Leishmania donovani is responsible for leishmaniasis, a disease transmitted by sandflies, while Bacillus anthracis causes anthrax, a bacterial infection. Plasmodium falciparum is the main cause of malaria, transmitted through Anopheles mosquitoes. Each of these pathogens has different transmission vectors, disease manifestations, and geographic distributions, highlighting the importance of identifying the correct