90-Second Read: Hantavirus risk from rodents may be higher in Pacific Northwest

You may be at greater risk of contracting a Hantavirus strain that can cause a deadly respiratory disease in humans if you live in the Pacific Northwest, a new study shows. About 10% of the rodents were actively infected, meaning they were carrying and could potentially shed the virus, the study reported. Sin Nombre is the most common cause of Hantavirus pulmonary syndrome in the United States.

Nearly 30% of rodents, 189 mice, voles and chipmunks, in the Palouse region of Washington and Idaho were found to have been infected at some point with the strain, known as Sin Nombre virus, or SNV. At least 864 cases were reported in the United States from 1993 to 2022, with a 36% case-fatality rate. Despite the relatively high prevalence of the virus in rodents, reports of human infections remain rare, which could indicate some infections are going unnoticed.

The study was conducted by Washington State University's College of Veterinary Medicine. Researchers trapped rodents across farms and natural areas in Whitman County, Washington, and Latah and Benewah counties in Idaho. It also indicates one rodent species could infect another.