Socioeconomic and environmental conditions influence the risk of dengue infection in a subtropical city of Argentina

Abstract

The increasing connectivity and urbanization of human population favor the reemergence and spread of dengue fever in subtropical and temperate regions, which poses onerous challenges to health systems. Analyzing the contribution of socioenvironmental conditions to the contagion risk is essential to design preventive strategies. In this retrospective analysis, we aim to assess the effects of social, demographic and environmental factors on the likelihood of becoming infected with dengue virus in Tucumán, the main subtropical city of Argentina. We implemented a case-control study to analyze the 2016 dengue outbreak. The control group included all persons reported with nonspecific febrile syndrome, and the cases were those confirmed with dengue virus after laboratory analyses. We recorded the age, sex and diagnostic date for every patient, and we georeferenced their house. This georeferentiation allowed us to estimate the distance to the nearest previous positive case (to control autocorrelation), population density, proportion of households with insufficient material constructive quality, overcrowding, educational level, NDVI, surface temperature and distance to nearest canal and cemetery. We constructed and compared logistic regression models to identify the combination of variables that best predicted dengue cases. Proximity to previous cases, cemeteries and canals, scarcity of surrounding vegetation, age and educational deficit were associated with an increased probability of being positive for dengue. In Argentina, socioeconomic differences are reflected in environmental inequalities, which reinforce the differential odds of suffering from dengue fever. Our results suggest that improving urban environmental quality may constitute an efficient way of preventing individual contagion of dengue and subsequent outbreaks.