Integration of temporal and spatial models for examining the epidemiology of African trypansomiasis

Abstract

A stochastic model was first developed to study the spatial dispersal of tsetse fly population, and subsequently integrated with a time oriented epidemiologic model. Such an integrated model was needed to understand better the epidemiology of cattle trypanosomiasis. Pre-existing data were used to determine the distributions of the random variables involved in the model. We used the model to assess several alternatives of preventing the spatial progression of trypanosomiasis. We address the following question: what size of protective barrier is required to prevent the spatial progression of trypanosomiasis? The vector control alternatives considered in this study included insecticide applications, vegetation clearing, wild animal depopulation, use of tsetse traps, and combinations of the above methods within a protective barrier. Simulation results indicated that a protective barrier, about 1000 m wide, was effective in stopping the spatial spread of cattle trypanosomiasis.