Tree die-off presents human health risk

Jan. 7, 2011 at 7:54 PM   |   Comments

DURANGO, Colo., Jan. 7 (UPI) -- A recent die-off of aspen trees in the U.S. West has swelled the population of rodents that carry a virus that can be deadly to humans, researchers say.

A tree-killing syndrome called sudden aspen decline, which has wiped out swaths of trees across the West in the past decade, has changed the numbers of creatures living around the trees, including some carriers of human disease, ScienceNews.org reported.

Deer mice at hard-hit sites in 2009 were almost three times as likely to carry sin nombre virus, which can be fatal to humans, compared with mice in less-ravaged aspen stands, researchers from Fort Lewis College in Durango, Colo., said.

People inhaling virus wafting from mouse urine or saliva can get hantavirus pulmonary syndrome, a disease that kills more than one-third of its victims.

Researchers compared aspen stands and found that in places that still had most of their aspens there were more species of small mammals than in the devastated plots. In the healthier aspen stands, the most abundant small mammal found was the montane vole, which doesn't make a good host for the sin nombre virus, researchers said.

In study sites that had lost at least two-thirds of their aspens, the most abundant species was the deer mouse, which isn't as choosy about its habitat as the vole is.

Erin Lehmer of Fort Lewis College speculates infection might have risen among deer mice as their growing dominance in the landscape let them encounter each other more frequently and get into more mouse fights.

Sin nombre spreads readily among rodents through bites, she says.

© 2011 United Press International, Inc. All Rights Reserved. Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI's prior written consent.
Recommended UPI Stories
Featured UPI Collection
Celebrity Couples of 2014 [PHOTOS]

Celebrity Couples of 2014 [PHOTOS]

Most Popular
Rock-eating bacteria discovered in buried Antarctic lake
Spiders prefer the city life
Seals, sea lions likely spread tuberculosis to humans
Endangered bats find sanctuary in Vermont power plant
Bill Gates to Mark Zuckerberg: I'll take the ice bucket challenge, and improve it
Trending News