El Niño Disease
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It's bad enough when El Niño puts a damper on wintertime sun and fun in Southern California. But when the warm Pacific waters cause health-related havoc, it's really bad news. Hi I'm Dave Thurlow and this is The Weather Notebook.

Scientists have found a link between El Niño and the spread of cholera across Southeast Asia. Cholera is a tragic bug: it can kill people in just a few hours by causing severe and fluid loss. The bacteria behind cholera tends to grow in swampy, brackish water, the kind found throughout the country of Bangladesh in particular. A group of scientists there recently compared hospital records to the waxing and waning of El Niño over 18 years. They found that cholera rates tend to go up each fall, but especially after an El Niño gets under way.

One likely reason is that El Niño tends to suppress the usual monsoon rains across southeast Asia. This allows the coastal swamps to warm up more than usual, helping cholera to thrive. If there's any good news we know that improved sanitation can greatly reduce the risk of cholera. The Deep South here in the U.S. was once subjected to massive cholera outbreaks. One of them almost wiped out Birmingham, Alabama, in 1873. Even back then, people noticed that hot, humid weather seemed to make the outbreaks worse. Nowadays, cholera is extremely rare in the U.S.--even when El Niño is doing its worst.

The big concern with many infectious diseases these days may be connected to El Niño, and that's global warming. Global warming will likely result in changing temperature and precipitation patterns that in some cases wil favor the spread of cholera and similar bacteria.

The Weather Notebook is funded in part by the National Science Foundation, The National Oceanic and Atmospheric Association, and Subaru.