Ecological study and risk mapping of leishmaniasis in an endemic area of Brazil based on a geographical information systems approach

Visceral leishmaniasis is a vector-borne disease highly influenced by eco-epidemiological factors. Geographical information systems (GIS) have proved to be a suitable approach for the analysis of environmental components that affect the spatial distribution of diseases. Exploiting this methodology, a model was developed for the mapping of the distribution and incidence of canine leishmaniasis in an endemic area of Brazil. Local variations were observed with respect to infection incidence and distribution of serological titers, i.e. high titers were noted close to areas with preserved vegetation, while low titers were more frequent in areas where people kept chickens. Based on these results, we conclude that the environment plays an important role in generating relatively protected areas within larger endemic regions, but that it can also contribute to the creation of hotspots with clusters of comparatively high serological titers indicating a high level of transmission compared with neighbouring areas.