What protozoan is responsible for causing sleeping sickness?

Sleeping sickness, also known as African trypanosomiasis, is caused by the protozoan parasite Trypanosoma brucei. This organism is transmitted to humans through the bite of infected tsetse flies, which are found mainly in sub-Saharan Africa. There are two subspecies of Trypanosoma brucei that cause sleeping sickness: Trypanosoma brucei gambiense, which leads to a chronic form of the disease, and Trypanosoma brucei rhodesiense, which causes an acute form.

The life cycle of Trypanosoma brucei involves an extracellular phase within the bloodstream of the host, where it can evade the immune system by changing its surface glycoproteins, making it particularly challenging to treat. The disease is characterized by symptoms such as fever, headaches, joint pains, and can progress to neurological symptoms, disrupting the sleep cycle, which is how it gets its name.

The other protozoan options mentioned are responsible for different diseases. Leishmania donovani is known for causing visceral leishmaniasis, also referred to as kala-azar. Trichomonas vaginalis causes trichomoniasis, a sexually transmitted infection. Plasmodium falcip