Trypanosomiasis is the name of the several diseases in vertebrates caused by parasitic protozoan trypanosomes of the genus Trypanosoma. The disease may also be called trypanosomosis but there is no greater authority for either; both terms are widely used in publication. More than 66 million women, men, and children in 36 countries of sub- Saharan Africa suffer from human African trypanosomiasis. There are two forms of African sleeping sickness, caused by two related parasites:
* Trypanosoma brucei gambiense
* Trypanosoma brucei rhodesiense
