African sleeping sickness

African trypanosomiasis or "sleeping sickness" is a disease caused by flagellated protozoans that live in blood and in the extracellular tissue fluid.

Human African trypanosomiasis is transmitted only in sub-Saharan Arica, where there are suitable habitats for the tsetse fly vector.

The 31 species and subspecies of Glossina have a wide range of environmental requirements, resulting in discontinuous distribution of the vector across the African tsetse belt.

During 1902 to 2012, 244 cases of African trypanosomiasis were reported in non-endemic countries – most before 1920 and after 2000. 74.3% in the pre-colonial era involved expatriates, missionaries and soldiers; and 78% were due to Trypanosoma brucei gambiense.

There are two forms of African trypanosomiasis: one, known as gambiense African trypanosomiasis, is endemic in West and Central Africa and causes over 95% of current cases,; the other, known as rhodesiense African trypanosomiasis, is endemic in East and southern African and accounts for the remainder of cases.

Gambiense African trypanosomiasis tends to be transmitted in forested areas along rivers and Rhodesiense African trypanosomiasis is transmitted is separated areas of woodland and savanna.

If left untreated, African trypanosomiasis causes biological damage and leads inexorably to death. If treated late, it can leave major irreversible sequelae: and since patients must stay in bed or in hospital for a long time, they are unable to work.
African sleeping sickness