Spatial Risk Models for Human Plague in the West Nile Region of Uganda

Abstract

The West Nile region of Uganda represents an epidemiologic focus for human plague in east Africa. However, limited capacity for diagnostic laboratory testing means few clinically diagnosed cases are confirmed and the true burden of disease is undetermined. The aims of the study were 1) describe the spatial distribution of clinical plague cases in the region, 2) identify ecologic correlates of incidence, and 3) incorporate these variables into predictive models that define areas of plague risk. The model explained 74% of the incidence variation and revealed that cases were more common above 1,300 m than below. Remotely-sensed variables associated with differences in soil or vegetation were also identified as incidence predictors. The study demonstrated that plague incidence can be modeled at parish-level scale based on environmental variables and identified parishes where cases may be under-reported and enhanced surveillance and preventative measures may be implemented to decrease the burden of plague.