Warming extends diseases into new areas, scientists say

Global warming — with an accompanying rise in floods and droughts — is fueling the spread of epidemics in areas unprepared for the diseases, say many health experts worldwide. Mosquitoes, ticks, mice and other carriers are surviving warmer winters and expanding their range, bringing health threats with them.

Malaria is climbing the mountains to reach populations in higher elevations in Africa and Latin America. Cholera is growing in warmer seas. Dengue fever and Lyme disease are moving north. West Nile virus, never seen on this continent until seven years ago, has infected more than 21,000 people in the United States and Canada and killed more than 800.

..Scientists have warned for more than a decade that climate change would broaden the range of many diseases. But the warnings were couched in the future, and qualified.

The spread of disease is affected by many uncertainties, including unforeseen resistance to antibiotics, failures of public health systems, population movement and yearly climate swings. For that reason, some scientists have been cautious about the link between disease and global warming.

But Paul Epstein, a physician who worked in Africa and is now on the faculty of Harvard Medical School, said that, if anything, scientists aren’t worried enough.

“Things we projected to occur in 2080 are happening in 2006. What we didn’t get is how fast and how big it is, and the degree to which the biological systems would respond,” Epstein said. “Our mistake was in underestimation.”

Lexington Herald Leader