Linking Wetland Ecosystem Services to Vector-borne Disease: Dengue Fever in the San Juan Bay Estuary, Puerto Rico

Mosquito-borne diseases are an increasingly important health concern, which pose great challenges for safe and sustainable control and eradication. This reality calls for management approaches that consider multiple aspects of the transmission cycle from a landscape and vector ecology perspective, to socio-economic elements that may increase exposure. This study seeks to better understand these pathways using dengue fever in the San Juan Bay Estuary (SJBE), Puerto Rico. Dengue is transmitted by Aedes aegypti, a species that thrives in cities. Here we ask which elements within the urban landscape could be managed to help prevent dengue outbreaks. We studied the potential of coastal wetlands in the SJBE to buffer vector proliferation, hypothesizing that wetland ecosystem services lead to lower dengue occurrence. We test this hypothesis using census-block level dengue data from 2010-13, including the largest epidemic in Puerto Rican history. Our analytical model includes socio-economic factors and environmental controls that may also affect dengue dynamics. Results from beta-binomial regressions and model averaging indicated that dengue occurrence was lower in neighborhoods with higher wetland cover even after controlling for population density and other socio-economic aspects. Our models suggest that heat hazard mitigation is partly responsible for the association between wetlands and dengue.