Environmental and demographic determinants of dengue incidence in Brazil

Abstract

Objective: To analyze the spatial distribution of dengue fever cases within an urban area of the São Paulo State, southeast Brazil.

Methods: Based on a methodology created by the authors, it was possible to organize the Brazilian Census data of 2010 into a regular grid of 250x250 meters each cell. This cell was the unit of analysis. Then, the 1 688 residential addresses of autochthonous dengue cases reported in 2013 in Caraguatatuba city were geocoded to calculate the incidence rate by cell. The dependent variable was the dengue incidence rate and the independent variables were classified into two types: environmental and sociodemographic. Finally, a Zero-Inflated Negative Binomial Regression was performed using the software R.

Results: The statistical analysis showed an association between dengue incidence rate and the environmental variable "proximity to strategic points (junk yards, tire repair shops and deposits of recyclable materials)." Dengue was also associated to the sociodemographic variables "proportion of households with per capita income up to 3 minimum wages", "proportion of nonwhite people" and "proportion of not owned households".

Conclusion: Dengue is associated to several factors related to its epidemic outbreak. In this complex context, results suggest that this infectious disease is socially conditioned, since it is more likely to reach population groups with specific characteristics, notably those with low socioeconomic status.