Catching Climate Fever: Diagnosing the Changing Environment of Infectious Disease

Abstract: What are the disease impacts of climate change? Climate-health research is a rapidly expanding field that intersects multiple disciplines and approaches. I review key concepts using a range of infectious disease examples from my own research group, and then focus on mosquito vectors of disease in the US. Climate and climate change affect the ecology of infectious diseases via disease hosts, vectors, and reservoirs. In the southern United States, Culex quinquefasciatus may be a primary vector for West Nile Virus (WNV) in many locations because of its affinity for urban environments and because they feed on humans and bird hosts. Changes in temperature and precipitation regimes may affect the population and season length of this mosquito, altering the risk of WNV transmission to humans. It is difficult to assess the impact of climate changes on local mosquito populations, given the paucity of observations, and therefore we have developed the Dynamic Mosquito Simulation Model (DyMSiM). Using downscaled general circulation model (GCM) projections for current and future conditions, we modeled mosquito population dynamics across the southern United States using DyMSiM. As expected, modeled mosquito populations responded differently by location, season, and time period. Temperature changes have a marked positive effect on mosquito population in fall, while summer showed a strong positive link between precipitation and mosquito populations. Higher temperatures led to a rise in populations during the cooler months, but during summer decreased breeding habitats due to drying from evaporation. In the Western US, projected drier conditions did not decrease mosquito populations because they rely heavily on permanent water sources which are not controlled by precipitation.

Refreshments following lecture on the IBS patio.

This lecture series was made possible by the generous support from The Beirne Carter Foundation.

Co-sponsored by the Environment and Society Program of the Institute of Behavioral Science and CIRES Center for Science and Technology Policy Research