Visceral leishmaniasis and vulnerability conditions in an endemic urban area of Northeastern Brazil

Trans R Soc Trop Med Hyg. 2018 Jul 23. doi: 10.1093/trstmh/try058. Online ahead of print.

Abstract

Background: Visceral leishmaniasis (VL) is considered an urban endemic that may be related to sociodemographic factors and urban infrastructure. The objective of this study was to analyze the conditions of vulnerability and the incidence of VL, and to identify the spatiotemporal pattern of the disease.

Methods: Data on reported cases of VL were collected from 2007 to 2016. Thematic maps on the spatiotemporal distribution were produced using values normalized by the area of the neighborhoods. The primary indicators of vulnerability were normalized for later construction of the synthetic indicators of vulnerability of social structure, household structure, and urban infrastructure, and from these, a vulnerability index was developed. The bivariate global Moran index was used to verify the existence of spatial autocorrelation between the incidence of VL and the conditions of vulnerability, while the bivariate local Moran index was used to identify the existence of spatial clusters.

Results: The 695 cases reported presented a diffuse distribution when the spatial pattern was evaluated. The incidence of the disease was correlated with worsened living conditions. Statistically significant clusters were revealed between the incidence of the disease and the vulnerability indicators of social structure, household structure, urban infrastructure and composite vulnerability index.

Conclusion: Addressing the local vulnerability conditions is important to the understanding of the distribution of visceral leishmaniasis, identifying the most susceptible areas, and planning control strategies.