2,900 Yosemite visitors warned about possible exposure to deadly hantavirus

The signature tent cabins in Curry Village at Yosemite National Park Yosemite National Park

(CBS News) About 2,900 Yosemite National Park visitors from around the world who stayed in Curry Village this summer have been notified about possible exposure to hantavirus, a mouse-borne illness that can develop into severe and often-fatal respiratory disease.

Man's death at Yosemite tied to rodent-borne disease, hantavirus

People who stayed in the cabins from June 10 through Aug. 24 have been notified by e-mail or letter about possible infection, Yosemite National Park spokeswoman Kari Cobb told CBSNews.com. In addition, visitors who were planning on staying in the tent cabins in Curry Village at Yosemite have been re-booked in other locations, while the 91 cabins undergo sanitation and retrofitting.

"We'll be spending a lot time to make sure they are rodent-proof, and they are completely clean," Cobb said.

On Aug. 27, the National Park Service said there were three confirmed and one probable case of Hantavirus Pulmonary Syndrome (HPS) in visitors who had stayed in Curry Village since June 2012, according to the Centers of Disease Control and Prevention (CDC). Two of the victims had died from the disease.

Hantaviruses are different viruses that are sometimes carried by rodents, according to the CDC. Some versions of the viruses carried by deer mice, white-footed mice, rice rats and cotton rats in North America can cause the rare, but deadly disease HPS. It is contracted when people breathe in the hantavirus through infected rodent urine and droppings; when people touch infected urine, droppings or nesting materials or through a bite from an infected animal. It is extremely rare to get the disease - since it was identified in 1993 there have been 60 cases in California and 587 nationally, according to the National Park Service.

HPS can lie dormant for one to five weeks. Symptoms begin with fever, severe muscle aches and fatigue. A few days later the patient will have a hard time breathing and may experience headaches, dizziness, chills, nausea, vomiting, diarrhea and stomach pain. The infection is fatal in about one-third of cases, the National Park Service reported.

There is no specific treatment, cure or vaccine for the disease, but the earlier someone is treated the better they tend to fare. Patients are often put into intensive care, intubated and given oxygen therapy to help relieve respiratory symptoms.

"The health of our visitors is our paramount concern and we are making every effort to notify and inform our visitors of any potential illness," Don Neubacher, Yosemite superintendent, said in a press release. "Because people often don't get sick from hantavirus until one to six weeks after exposure, we are encouraging anyone who stayed in Curry Village since June to be aware of the symptoms of hantavirus and seek medical attention at the first sign of illness."

The problem with the signature tent cabins is they are made up of an outer wall and inner wall with insulation filling the gap, Cobb explained. Authorities believe that the mice are in-between the walls and spreading the infection that way.

Cobb said since they've sent out the warnings, some people have reported that they've felt ill since they stayed at Curry Village. However, since the hantavirus is only detected with a blood test, there have no additional confirmed cases as of yet.