Sleeping sickness is a parasitic disease of humans and other animals. It is caused by

Sleeping sickness, also known as African trypanosomiasis, is a parasitic disease caused by protozoan parasites of the genus Trypanosoma [1]. Specifically, the disease is caused by the species Trypanosoma brucei, which is transmitted to humans and animals through the bite of an infected tsetse fly (Glossina species) [3]. There are two primary types of the human disease: West African sleeping sickness, caused by Trypanosoma brucei gambiense, and East African sleeping sickness, caused by Trypanosoma brucei rhodesiense [1]. In animals, related parasites cause a similar condition known as nagana [2]. While other options like Naegleria refer to different protozoans (such as the brain-eating amoeba), Trypanosoma is the definitive causative agent for sleeping sickness. The disease is endemic to sub-Saharan Africa, where the tsetse fly vector is found [3].

Sources

1. [1] https://www.sciencedirect.com/topics/veterinary-science-and-veterinary-medicine/trypanosoma-equiperdum
2. [3] https://www.ncbi.nlm.nih.gov/books/NBK535413/
3. [2] https://www.cdc.gov/sleeping-sickness/about/index.html