Climate change affects global spread of infectious diseases

Climate change affects the spread of infectious diseases worldwide with serious impacts to human health and biodiversity conservation, disease ecologists say. Writing in the journal Science, they propose modeling the way disease systems respond to climate variables could help public health officials and environmental managers predict and mitigate the spread of lethal diseases. Climate change and its effects on diseases that threaten humans has been a subject of debate for the last decade, study lead author Sonia Altizer of the University of Georgia said. "For a lot of human diseases, responses to climate change depend on the wealth of nations, healthcare infrastructure and the ability to take mitigating measures against disease," she said. "The climate signal, in many cases, is hard to tease apart from other factors like vector control and vaccine and drug availability." Climate warming already is causing changes in diseases affecting wildlife and agricultural ecosystems, she said. A lungworm that affects muskoxen in the arctic, for example, can now be transmitted over a longer period each summer, making it a serious problem for the populations it infects, the researchers said. "In a number of infectious disease systems, such as Lyme disease and West Nile virus, biodiversity loss is tied to greater pathogen transmission and increased human risk," study coauthor Richard Ostfeld of the Cary Institute of Ecosystem Studies said. "Moving forward, we need models that are sensitive to both direct and indirect effects of climate change on infectious disease. "We need to transcend simple arguments about which is more important -- climate change or socioeconomics -- and ask just how much harder will it be to control diseases as the climate warms?"