January 15, 2009

European virus linked to global warming

A sometimes deadly rodent-borne viral disease has become an epidemic in parts of Europe due to global warming, Belgian researchers said Thursday.

The disease nephropathia epidemica was scarcely known before 1990, but is now an epidemic in Belgium, France, Germany, Netherlands and Luxembourg, said viral epidemiologist Dr Jan Clement of the University of Leuven's Rega Institute near Brussels.

Thirty-eight percent of known cases occurred between 2005 and 2007, Clement said in the International Journal of Health Geographics, which focuses on relationships involving people, location or environment, time and health.

The fact that the growing combined effect of hotter summer and autumn seasons is matched by the growth of NE in recent years means this epidemic can be considered an effect of global warming, Clement said.

The disease is transmitted by bank voles, which are mouse-like rodents that have increased in number in recent years due to a rise in acorns and beechnuts, known as mast, falling from oak and beech trees, the researchers said. The voles eat the nuts.

Warmer weather has increased the amount of mast the trees make -- and warm summers raise the chances people will visit forest areas where the voles live, the researchers said.

People with NE typically get a sudden fever and headache along with back pain and gastrointestinal symptoms. They may also have internal hemorrhaging that can lead to death.