Analysis of spatial clustering, time trend, social vulnerability and risk of human visceral leishmaniasis in an endemic area in Brazil: an ecological study

Background More than 95% of visceral leishmaniasis (VL) cases in Latin America occur in Brazil, most of them in the northeast. The objective of this study was to identify spatial clusters with the highest risks of VL and to analyse the temporal behaviour of the incidence and the effects of social vulnerability on the disease transmission dynamic in northeastern Brazil. Methods All confirmed cases registered as residents in the state of Pernambuco during the period from 2007 to 2017 were analysed. The Local empirical Bayesian method was applied and the association -between the VL incidence rate and municipal social vulnerability was tested via classic multivariate regression. Results A total of 1186 new cases were registered during the study period. Spatial analysis showed heterogeneous distribution, with the highest rates observed in the Sao Francisco and Sertao mesoregions. Moreover, the main factors associated with VL were urban infrastructure, income and work. Conclusions It was observed that spatial and temporal techniques are important tools for defining risk areas for VL, in conjunction with the evaluation of indexes of social vulnerability, which was shown to be an important factor for comprehending associations with VL in the state of Pernambuco.