Monitoring Killer Mice from Space: Green on Satellite Images Warns of Hantavirus Outbreaks

The risk of deadly hantavirus outbreaks in people can be predicted months ahead of time by using satellite images to monitor surges in vegetation that boost mouse populations, a University of Utah study says. The method also might forecast outbreaks of other rodent-borne illnesses worldwide.

"It's a way to remotely track a disease without having to go out and trap animals all the time," says Denise Dearing, professor of biology at the University of Utah and co-author of the study published online on Wednesday (16 February 2011) in the journal Global Ecology and Biogeography. "The satellite measures the greenness of the Earth, and we found that greenness predicts deer mouse population density."

While the study focused on hantavirus in deer mice, its findings could help health officials fight other rodent-borne diseases such as rat-bite fever, Lyme disease, bubonic plague, Lassa fever, salmonella infection and various hemorrhagic fevers.

The method was tested on deer mice that carry hantavirus and proliferate when their food supply is abundant, "but it potentially could be applied to any animal that responds to vegetation," says Dearing. "It would have to be calibrated against each specific species of rodent and the disease, but it's really powerful when it's done."

The study combined satellite imagery with data from thousands of mice captured over three years in central Utah. Both the total number of trapped mice and the number of mice with the disease, a strain of hantavirus known as Sin Nombre virus, climbed after peaks in greenery.

Sin Nombre virus is carried by rodents, primarily deer mice, in the western United States. In humans, it causes a disease known as hantavirus pulmonary syndrome. It was discovered in 1993 after several young, otherwise healthy people in the Four Corners area of Utah, Colorado, New Mexico and Arizona died of a mysterious respiratory illness.