Spatiotemporal patterns and integrated approach to prioritize areas for surveillance and control of visceral leishmaniasis in a large metropolitan area in Brazil

Abstract

Visceral leishmaniasis (VL) is a neglected disease with worldwide distribution. Brazil is the country with the largest number of cases in the Americas, and the state of Minas Gerais presents a high VL-related burden and a high case fatality rate. We aimed to analyse the spatial and spatiotemporal patterns of VL occurrence and to identify priority risk areas for surveillance and control in the metropolitan region of Belo Horizonte-MG, the third largest metropolitan area in Brazil. An ecological study was conducted considering all cases of VL in humans confirmed from 2006 to 2017. The crude and smoothed incidence rates were used to analyse the distribution patterns of the disease (dispersed, random, or clustered) based on global and local indicators of spatial association and space–time risk assessment. Positive spatial autocorrelation and spatial dependence were found between incidence rates. It was possible to observe a high concentration of VL cases in the metropolitan core area, with the identification of two high-risk clusters in strictly urban areas, showing an urban association with the disease. Ten municipalities were categorised as high risk for VL occurrence. Our results provide evidence for making decisions in surveillance programs, suggesting the prioritisation of the municipalities with more risk of transmission.