A new study has found that nearly one in three rodents in the Pacific Northwest of the United States may be infected with hantavirus, the pathogen responsible for a deadly outbreak on a Dutch cruise ship. The research, published in Emerging Infectious Diseases, sampled 189 rodents from farms and natural areas in Washington and Idaho.
Of the rodents captured, including deer mice, voles, and chipmunks, about 10 per cent were actively infected, meaning they could shed the virus. The study's authors expressed surprise at the high prevalence and the lack of existing data for the region.
The hantavirus strain found in the Pacific Northwest differs from the Andes 'Sin Nombre' strain linked to the cruise ship outbreak on the MV Hondius, which infected 11 people and resulted in three deaths. That strain has shown a rare capacity for human-to-human transmission in close quarters.
Hantavirus typically spreads to humans through inhalation of airborne particles from contaminated rodent droppings, urine, or nesting materials. Scientists warn that disturbing rodent nests, particularly with equipment like leaf blowers, can increase exposure risk.
To reduce infection risk, researchers recommend ventilating spaces and using wet-cleaning methods. Future studies aim to understand how often people are exposed and how behaviour influences infection risk, as severe cases are more likely to be tested.
