The parasites of the genus Trypanosoma cause African trypanosomiasis (also known as sleeping sickness).
Infected tsetse flies, which are only found in Africa, spread the disease.
The sleeping sickness illness is separated into two stages. In the first stage of infection, infected people frequently have a fever, headache, muscle and joint pain, and lymph node inflammation.
The second stage, which can occur in a matter of weeks or up to two years, is characterized by the brain and spinal cord involvement, as well as personality changes, sleep difficulties, and deep lethargy, and can lead to death if left untreated.
There were numerous large outbreaks of sleeping sickness in the twentieth century, though the number of new cases reported annually has fallen dramatically since then.