Spatial correlation of incidence of dengue with socioeconomic, demographic and environmental variables in a Brazilian city.

Dengue is endemic in most tropical countries. The reasons for its maintenance are related to several risk factors including socioeconomic factors. Urban space and time are also two important dimensions to describe the dynamics of an outbreak. The aim of this study was to evaluate the existence of a spatial correlation of the incidence of dengue and to identify variables that explain the spatial dependence in a medium-sized city of Brazil. We analyzed registered autochthonous dengue cases from September 1994 to August 2002 correlating them with socioeconomic, demographic and environmental variables using the Moran index. Our results indicate spatial dependence of the incidence of dengue and that socioeconomic factors were critical both at the beginning of the study and later on; other variables related to the organization of urban space were also involved in the occurrence of the disease. The use of spatial analysis tools is important to identify critical control areas with several variables intimately related to the modulation of the disease dynamics.