Yosemite Hantavirus Problems May Pose Risk for 10,000 People: CDC

As many as 10,000 visitors to Yosemite National Park may have been exposed to the often-deadly hantavirus, according to federal health officials. 

Letters have been sent to about 2,900 people who stayed in the Signature Tent Cabins in the Curry Village section of the park, warning them that they may have been exposed and to keep alert for hantavirus symptoms.

However, the U.S. Centers for Disease Control and Prevention (CDC) puts the estimate of people who may have been exposed to the virus at closer to 10,000, including not only those who booked stays in the tent cabins, but by calculating the number of guests they brought with them as well.

The Signature Tent Cabins have been shut down indefinitely following the hantavirus outbreak at Yosemite, which has killed at least two and sickened six. Additional cases are suspected but have not yet been confirmed, health officials say.

Hantavirus is transferred to humans when they breathe air contaminated with the virus or come in contact with saliva, urine or droppings from contaminated rodents.

With the Yosemite hantavirus problems, deer mice are suspected of having carried the virus to humans. The illness can incubate for up to six weeks until common symptoms, often confused with the flu, appear. Early symptoms include fever, headaches, muscle aches, stomach problems, dizziness and chills. Later, more severe, symptoms include coughing and shortness of breath.

The deer mice believed to have transmitted the virus were likely living inside the structure of the tent cabins. The mice are native to central and western United States and Canada. One report estimated that about 20% of the mice in Yosemite carry the hantavirus.

Officials indicate that the double-walled design of the “signature” tents, which is meant to keep out the elements, were ideal nesting places for the mice. Park workers are attempting to seal the tent cabins against deer mouse intrusion, but the creatures are ubiquitous in the park and can go through holes only a quarter inch in diameter.

Photo Courtesy of MiguelVieira via Flickr/CC 2.0