Parasitic zoonoses

The African trypanosomoses are diseases of both man and his livestock. There are two forms of human trypanosomosis or sleeping sickness: Gambian or Rhodesian sleeping sickness, roughly corresponding to a West, Central or East African distribution respectively. Gambian sleeping sickness runs a more protracted and chronic course than the Rhodesian form; nevertheless, human trypanosomosis is invariably fatal if not treated. Animal reservoir hosts, both wild and domestic, assume greater importance for Rhodesian sleeping sickness than Gambian sleeping sickness, and the former is often an occupational hazard of those visiting or working in wildlife areas, e.g. tourists, hunters. Animal trypanosomosis transmitted by tsetse is generally referred to as Nagana, while the disease transmitted by other bloodsucking flies outside the African tsetse belt is known chiefly as Surra, but also by a variety of local names.

Sleeping sickness control measures are aimed either at the trypanosome or the fly. Human cases are detected by active or passive surveillance and cured by treatment with trypanocidal drugs.Control of the tsetse vector is by application of residual insecticides or bush clearing and, more recently, by traps or insecticide-impregnated targets, or by wholesale release of sterile males. Tsetse control is more widely employed for the control of animal trypanosomosis than sleeping sickness.