Investigation into the ecology of trypanosomiasis in the Lungawa Valley, Zambia

Abstract

The Luangwa Valley is recognised as a focus of endemic infection with human sleeping sickness caused by Trypanosoma bruceirhodesiense. Extensive infection of the wildlife population with many species of trypanosome has been identified and livestock keeping is almost non-existent due to losses from trypanosomiasis and predation by wild animals. The aim of this study was to investigate the ecology of trypanosomiasis in this mult-host wildlife community, relatively free from anthropogenic influences. Particular focus was to be applied to the role of common warthog, phacocoerus aethipicus, within the reservoir community. The thesis initially reviews the history of protected area management in the Luangwa Valley. Remotely sensed imagery is then used in a study of the vegetation units of Luambe National Park. A supervised classification algorithm utilising fuzzy logic is used to generate a land cover classification of the part with an overall accuracy of 71%. Surveys of the tsetse and wild mammal population in Luambe national park are then presented. Data collected from the tsetse survey are analysed using generalised linear models with mixed effects to investigate factors influencing the trypanosome prevalence in tsetse, as well as the distribution and apparent density of tsetse. The density of tyhe host mammal population is assessed using distance sampling techniques and the distribution of warthog burrows mapped. Finally, a cross-sectional survey of trypanosome prevalence in the wild animal population of the Luangwa Valley is described, using novel molecular techniques for diagnosis. Risk factors for infection are analysed using logistic regression analysis and the host distribution for each trypanosome species described.