Two organisms, T. brucei rhodesiense and T. brucei gambiense cause sleeping sickness. The more severe form of the illness is caused by rhodesiense.
T. brucei gambiense is the cause of a persistent infection that lasts several years until it finally develops into a coma, from which the patient cannot be woken. Hence the name 'sleeping sickness'.
If the central nervous system is severely affected, the patient can no longer be cured, and eventually dies, possibly from other infections that may be superimposed on the primary disease.
Long trousers, long-sleeved jackets and socks thick enough to stop the insects biting will protect you, but it may be hard to follow such advice in a hot climate.
Who is at risk for African sleeping sickness?
The only people at risk for African sleeping sickness are those to travel to Africa. That’s where the tsetse fly is found. The parasites that cause the disease are passed on only by the tsetse fly.
The tsetse flies live only in rural areas. They live in woodland thickets of the savanna and dense vegetation along streams. Visitors to cities and other urban areas are usually not at risk. The disease is found mainly in tropical Africa. The greatest risk of getting it is in:
Angola
Central African Republic
Chad
Congo
Democratic Republic of Congo
Malawi
Tanzania
Sudan
Uganda
Zambia