Aedes aegypti , a dengue virus vector mosquito, at the margins: Sensitivity of a coupled natural and human system to climate change

Dengue viruses circulate between mosquito vectors and humans, causing an estimated 300-million dengue infections annually. In the last decade, the Americas have experienced a dramatic increase in severe disease cases (dengue hemorrhagic fever), with devastating public health consequences. Of particular concern is the potential for the expansion of intense dengue virus transmission into cooler, high altitude cities that are presently outside of transmission zones such as Mexico City, but may be at risk under scenarios of climate change. To address this problem, we are employing a coupled natural and human systems approach to explore the ecology of Aedes (Ae.) aegypti, the mosquito vector of dengue viruses, in Mexico. A field study is being conducted along a transect from Veracruz City to Puebla City, ranging from relatively warm and wet low-elevation coastal environments with well established vector mosquito populations and intense dengue virus transmission, to comparatively cool and dry high-elevation mountainous areas which currently are free of the mosquito vector and local virus transmission. Along the transect we are measuring how climatic, socio-economic and infrastructure factors are coupled with Ae. aegypti abundance. These data are being synthesized into spatially and temporally predictive models to examine if, how, and why the range of the dengue vector Ae. aegypti may change in the future. Observational and modeling results from two field seasons will be presented, indicating strong linkages between climate and mosquito presence and abundance.