Factors Associated with Distribution of Leishmaniasis Disease and Vectors in Madre de Dios, Peru

Abstract

While the Madre de Dios department of Peru has the nation's highest leishmaniasis incidence, limited research on the disease and its sand fly vector exists in the region. Considering the diverse and adaptive nature of sand flies, understanding vector ecology is essential to directing leishmaniasis control efforts. This study addresses this need by investigating the following aims: 1) describe sand fly abundance and biodiversity in communities along the Madre de Dios River; 2) identify environmental and socio-demographic factors associated with sand fly abundance and biodiversity in these communities; and 3) examine ecological risk factors associated with leishmaniasis in the communities. In order to accomplish these aims, the research team collected sand flies, obtained leishmaniasis case data, conducted community and household surveys, measured soil samples and studied land cover data in communities along the Madre de Dios River. We compared sand fly abundance, sand fly biodiversity and leishmaniasis incidence with soil chemistry, socio-demographic and land cover measures. We ran negative binomial regressions and Poisson regressions to investigate bivariate relationships between dependent and independent variables. We developed a multivariate model that predicts greater potential vector and non-vector abundance in areas with greater forest coverage, lower infrastructure indices and lower soil pH. This study provides an important overview of endemic sand fly fauna in Madre de Dios and presents an initial description of factors associated with sand fly populations in the region.