Monitoring the incidence of trypanosomosis in cattle during the release of sterilized tsetse flies on Unguja Island, Zanzibar

Abstract

The incidence of trypanosomosis in sentinel cattle on Unguja Island, Zanzibar, was monitored every two to five months in 1994-97 to observe changes in disease transmission attributable logically to the application of insecticides, the release of sterilized tsetse flies (Glossina austeni Newstead) and the consequent decline and eradication of the wild tsetse population. Two parasitological techniques (microhematocrit centrifuge and buffy coat) were used to monitor the disease incidence caused by Trypanosoma congolense Broden and T. vivax Ziemann. T. congolense and T. vivax were detected in 1994 and 1995, but only T. vivax was detected thereafter. By 1997, the incidence of bovine trypanosomosis was only 0.1%. There was evidently no increase in disease incidence due to the release of sterilized isometamidium chloride-treated male tsetse flies.

Keywords

• Trypanosoma congolense
• Trypanosoma vivax
• Trypanosomose
• Glossina austeni
• Morbidité
• République-Unie de Tanzanie