The geographical prevalence and potential epidemiology of heartwater in Botswana: implications for planning control under climate change #

Abstract

Heartwater caused by Ehrlichia ruminantium is a widespread animal health problem in Botswana. Although long known to be endemic, its current distribution and possible future occurrence in new areas within the country requires updating to help guide planned control in the midst of climate change. Thus an understanding of the spatial occurrence of the disease and its environmental risk factors is essential for control and management planning. The goal of this paper was to explore the current and potential spatial occurrence of heartwater across Botswana and its associated environmental factors. To reach this goal, geographical information systems were used to map the distribution of heartwater infection and also overlay infection data with interpolated environmental surfaces. The derived maps indicate both a widespread occurrence of infection and a marked variability in infection prevalence, with the south east and north eastern parts of the country having the highest incidence rates while the western part has the highest potential for disease occurrence. The results revealed the occurrence of heartwater in the east but absence in the west and also potential areas for disease outbreak, in which climate change alteration of environmental factors could trigger its establishment.