Malaria risk and temperature: Influences from global climate change and local land use practices

Abstract

An estimated 700,000 to 2.7 million people die of malaria each year, and 75% of those are African children (www.cdc.gov/malaria). Recent resurgence in the East African highlands involves multiple factors, from climate and land use change to drug resistance, variable disease control efforts, and other sociodemographic factors (1). But malaria is an extremely climate-sensitive tropical disease, making the assessment of potential change in risk due to past and projected warming trends one of the most important climate change/health questions to resolve. Pascual et al . (2) now provide important new insights toward answering this malaria/climate question in their article in this issue of PNAS. Pascual’s research team used a de-trended time series of temperature and documented a warming trend in the East African highlands from 1950 to 2002, concomitant with increases in malaria incidence. Moreover, their findings confirm the importance of the well recognized nonlinear and threshold responses of malaria (a biological system) to the effect of regional temperature change (Fig. 1). For example, showing that the biological response of mosquito populations to warming can be more than an order of magnitude larger than the measured change in temperature represents a stunning finding, critical in advancing risk assessment of climate change impacts. Those who argue that we need not worry about small shifts in temperature should … *To whom correspondence should be addressed. E-mail: patz{at}wisc.edu