Are temperature suitability and socioeconomic factors reliable predictors of dengue transmission in Brazil?

Abstract

Background Dengue disease is an ongoing problem, especially in tropical countries. Like many other vector-borne diseases, the spread of dengue is driven by a myriad of climate and socioeconomic factors. Over recent years, mechanistic approaches have predicted areas of dengue risk according to the temperature effect on mosquitos' lifespan and incubation period shaping their persistence and competence in transmission. Within developing countries such as Brazil, heterogeneities on socioeconomic factors are expected to create variable conditions for dengue transmission by its main vectors. However, both the relative role of socioeconomic aspects and its association with the temperature effect in determining the effective dengue prevalence are poorly understood. Methodology/Principal findings Here we gathered essential socioeconomic factors comprising demography, infrastructure, and urbanization over 5570 municipalities across Brazil and evaluated their relative effect on dengue prevalence jointly with a previously predicted temperature suitability for transmission. Using a simultaneous autoregressive approach (SAR), we showed that the variability in the prevalence of dengue cases across Brazil is highly explained by the combined effect of climate and socio-economic factors. Moreover, the temperature effect on transmission potential might be a better proxy at some dengue epidemy seasons but the socioeconomic factors are tightly linked with the recent increase of the dengue prevalence over Brazil. Conclusions/Significance In a large and heterogeneous country such as Brazil recognizing the drivers of transmission by mosquitoes is a fundamental issue to effectively predict and combat tropical neglected diseases as dengue. Ultimately, it indicates that not considering socioeconomic factors in disease transmission predictions might compromise efficient strategies of surveillance. Our study indicates that sanitation, urbanization, and GDP are regional indicators that should be considered along with temperature suitability for dengue transmission, setting a good starting point to effective vector-borne disease control.