90-Second Read: Study finds deadly Hantavirus more widespread in Pacific Northwest rodents than expected

A Hantavirus that can cause a deadly respiratory illness in humans may be more common in rodent populations in parts of the Pacific Northwest than previously re PULLMAN, Wash. Hantavirus has recently been in the headlines because of an outbreak of Andes virus on a cruise ship. The study's field work was conducted in the summer of 2023, when researchers trapped rodents across farms and natural areas in Whitman County, Washington, and Latah and Benewah counties in Idaho.

Researchers found that nearly 30% of rodents tested showed evidence of past infection with the Sin Nombre virus, and about 10% were actively infected, meaning they were carrying the virus and could potentially shed it. From 1993, 2022, 864 cases were reported in the U.S., with a 36% case-fatality rate. A total of 109 of those cases occurred in Idaho, Oregon, and Washington.

While rare, it is the only Hantavirus known to spread between people. SEE ALSO | Sin Nombre Hantavirus case tied to home mouse exposure in Chelan County In the lab, researchers found evidence of both active infections and antibodies, indicating past infection in deer mice and voles, suggesting the virus may move between species. Rodents can spread the virus among themselves through saliva and direct contact, but human infections typically occur when people inhale airborne particles from contaminated rodent droppings, urine, or nesting materials.