Aspens bust, diseased mice boom
SALT LAKE CITY — Recent diebacks of aspen trees in the U.S. West may end up increasing the risk posed by a lethal human pathogen, a new study suggests.
A tree-killing syndrome called sudden aspen decline that has wiped out swaths of trees across the West in the past decade has also changed the kinds, numbers and interactions of creatures living around the trees, researchers have found — including some carriers of human disease. 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, Erin Lehmer of Fort Lewis College in Durango, Colo., and her colleagues reported January 4 at the annual meeting of the Society for Integrative and Comparative Biology.
The deer mouse Peromyscus maniculatus looks ironically cute in pictures at meeting presentations, but the Centers for Disease Control and Prevention ranks it as the main rodent reservoir for sin nombre virus. Infected deer mice don’t show many symptoms, but people inhaling virus wafting from mouse urine or saliva can get quite sick with hantavirus pulmonary syndrome.
Unknown to medicine until 1993, hantavirus pulmonary syndrome starts with muscle aches, chills, fever and stomach upset. Later, fluid fills the lungs; more than a third of victims have died. In 2010, the CDC logged 560 cases in 32 states stretching from California to Maine, but mostly in the West.