More countries eliminate human African trypanosomiasis as a public health problem: Benin and Uganda (gambiense form) and Rwanda (rhodesiense form) Human African trypanosomiasis (HAT), or sleeping sickness, transmitted by tsetse flies in sub-Saharan Africa, is a life-threatening disease that afflicts poor rural populations. It is caused by trypanosome parasites of 2 subspecies: Trypanosoma brucei gambiense in West and Central Africa, and T. b. rhodesiense in East Africa. HAT transmission can be reduced and interrupted by deploying and maintaining capacities for testing people at risk in order to detect and treat cases, and by controlling tsetse populations that are in contact with humans.