90-Second Read: Five things to know about Hantavirus from a Stanford Medicine expert

Hantavirus is rare and unable to cause a global pandemic, said Jorge Salinas, MD, the medical director of infection prevention at Stanford Health Care. We asked him what people need to know about Hantavirus. In one recent study, about 3% of deer mice and white-footed mice across the United States tested positive for Hantavirus, with geographic hotspots in Virginia, Colorado and Texas. A cluster of Hantavirus cases, usually spread only by wild rodents, was diagnosed on a trans-Atlantic cruise ship.

The outbreak comes roughly a year after Hantavirus was in the news for killing Betsy Arakawa, wife of actor Gene Hackman. In the last 30 years, the CDC has logged 890 cases of Hantavirus disease in humans, with 94% of cases west of the Mississippi and most occurring in Colorado, Arizona or New Mexico. Like the most severe COVID-19 cases, deaths from Hantavirus may be due to an overactive immune response. Hantavirus is a zoonotic infection, meaning it originates in animals but can cause disease in humans.

Together, the two stories underscore that while Hantavirus remains rare, it is not confined to remote jungles. Hantavirus has been detected in more than 100 species of mammals, including foxes and bats, but is primarily found in wild rodents, which can have persistent Hantavirus infections without symptoms. In 2018, the Andes strain of Hantavirus spread throughout a small village in Argentina. But Hantavirus, even the Andes strain, is not efficient at spreading between people.

Rare as it is, Hantavirus is not something to take lightly; its fatality rate is much higher than more common viruses such as influenza and COVID-19. Early symptoms of Hantavirus pulmonary syndrome, including fever, fatigue and muscle aches, show up anywhere from 4 to 42 days after exposure and might be mistaken for the flu. The picture looks slightly different for those heading into wilderness areas in the Western United States, where Hantavirus circulates in wild rodent populations.