Microwaves and memory loss.

For the first time, researchers have confirmed a long-suspected link between precipitation and plague. After reviewing nearly half a cen-tury's worth of data, a team of scientists from New Mexico and Colorado have found a strong tie between above-average precipitation during New Mexico winters and an increase in human cases of the still-dreaded plague. Their research, funded by the National Science Foundation, was published in the November 1999 issue of the American Journal ofTropicalMedicine and Hygiene. A pattern of wet years followed by outbreaks of plague has been observed around the world for more than a century, but a direct link to precipitation, particularly in a specific season, has never been proven. "That's what makes this dramatic," says Paul Epstein, associate director of the Center for Health and the Global Environment at Harvard Medical School in Boston, Massachusetts. Plague, caused by the bacterium Yersinia pestis, can kill within a matter of days if not treated with antibiotics. High rodent populations are one well-known factor governing the spread of the disease among humans (plague is transmitted by the fleas carried on rodents). Team leader Robert Parmenter, a research associate professor in the biology department at the University of New Mexico at Albuquerque, says he and his colleagues knew that rodent numbers tend to increase when higher levels of precipitation lead to increased food availability. But they also knew that human factors such as crowding , behavior, sanitation, and land use practices, along with the biology and behavior of both fleas and their rodent hosts, could influence the spread of plague. Some 1,000-3,000 cases of the disease are reported worldwide each year, according to the World Health Organization, including 10-15 cases in the United States. Fifty-five percent of U.S. cases have occurred in New Mexico. To test whether precipitation alone might influence Rain of plague. Above-average precipitation is linked with increases in cases of plague. the spread of plague, Parmenter's team examined data on precipitation and 211 plague cases that occurred from 1949 to 1996 in 38 New Mexico locations. They found that 60% of the cases occurred in years with above-average precipitation from October through May, as measured within about 20 kilometers of each plague case. They also saw a hint of increased plague cases with above-average local summer precipitation and with above-average precipitation when viewed statewide (during summer and winter) or on a global scale (during winter alone), but these …