Sleeping sickness or African trypanosomiasis is a parasitic disease in people and animals, caused by protozoa of genus Trypanosoma and transmitted by the tsetse fly. The disease is endemic in certain regions of Sub-Saharan Africa, covering about 36 countries and 60 million people. It is estimated that 50,000 to 70,000 people are currently infected, the number having declined somewhat in recent years. Three major epidemics have occurred in the past hundred years, one from 1896–1906 and the other two in 1920 and 1970.