A quantification of the risk of trypanosomiasis infection to cattle on the south Kenya coast.

The number of trypanosome-infected bites received by cattle grazed around an 8 ha area of forest harbouring a semi-isolated population of Glossina pallidipes Austen was estimated. The absolute size of the tsetse population was determined by mark-release-recapture techniques, the tsetse host range by the identification of blood-meals, and trypanosome infection rates by dissection of samples of tsetse. Feeding frequency was estimated and the number of cattle present was known. It was estimated that each cow received, from G. pallidipes, one infective inoculum of T. congolense every 5.8 days during the first experiment and 5.0 days in the second. For T. vivax results were 3.2 and 79.1 days, respectively.