Washington Health Officials Warn of Increased Hantavirus Risk

With the coming of spring, the warnings from the Washington state health department have increased about the dangers of Hantavirus exposure.

Infection with Hantavirus can lead to Hantavirus Pulmonary Syndrome (HPS) which the Center for Disease Control (CDC) states, “is a severe, sometimes fatal, respiratory disease in humans caused by infection with a Hantavirus.”

People become infected with Hantavirus through contact with infected rodents or their dropping. Cases are most common during the spring and summer when maid services clean up areas where the rodents proliferate.

According to Fox News, “People who uncover signs of mice or other rodents need to take precautions to avoid catching a rodent-carried disease like Hantavirus. Diseases spread by rodents are fairly rare in Washington State, but they can be serious or even deadly.”

deer mouse
Deer Mouse caught in a trap. Not recommended for domestic keeping.

The danger is not restricted to Washington State. In Riverside County, California, four out of 17 mice collected by health officials in January tested positive for Hantavirus. There has never been a documented case of HPS in Riverside County, however.

“The risk of humans getting the disease is extremely low,” said Dottie Merki, of the Riverside County Environmental Health Department to the Press Enterprise. “These (mice) were out in the wild, nowhere near any homes.”

“Ten to 15 percent of mice we test are positive,” Merki added.

The Hantavirus is a relatively rare disease but achieved notoriety in 1993 when an outbreak of HPS occurred in the Four Corners area in the southwestern United States. The carrier of the virus was identified as the deer mouse by research done at the University of New Mexico. Since it was identified, through June 2012, there have been 602 confirmed cases of HPS in the United States. The majority of these are in the southwest, but there have been cases throughout the western United States.

The deer mouse is a common rodent across North America and due to the deadliness of Hantavirus has come under more scrutiny. During the 1993 outbreak, the deer mouse population increased due to the El Nino weather effects. According to a 2009 study, changes in weather and precipitation “enhance hantavirus prevalence when host population dynamics are driven by food availability.”