(NaturalNews) The U.S. Centers for Disease Control and Prevention is warning that as many as 10,000 people who stayed in tent cabins at Yosemite National Park over the summer could be at risk for contracting a deadly rodent-borne hantavirus.
In response to the exposure, the CDC has urged laboratory testing of patients who begin to exhibit symptoms that are consistent with the lung disease known as hantavirus pulmonary syndrome. In particular, the agency is warning those who stayed in the park tents between June and August, and is encouraging doctors who encounter such patients to immediately notify state health departments.
To be sure, three campers have died after contracting hantavirus health officials say is linked to Yosemite, while five others have gotten sick but survived, multiple reports have said. The federal health agency said more suspected cases are currently being investigated from "multiple health jurisdictions." Several cases, reports have said, are yet to be confirmed.
Casualty count is likely to go higher
Most victims are thought to have been infected while staying in one of 91 "Signature" tent-style cabins in the park's popular Curry Village camping site.
"An estimated 10,000 persons stayed in the 'Signature Tent Cabins' from June 10 through August 24, 2012," the CDC said in a statement. "People who stayed in the tents between June 10 and August 24 may be at risk of developing HPS in the next six weeks."
In response, Yosemite officials have shut down all 91 of the insulated tent cabins after discovering deer mice inhabiting them. The mice carry the disease and can squeeze through holes the size of pencil erasers to gain access to the double walls of the cabins, where they nest.
Yosemite authorities have said they have contacted some 3,000 parties of visitors who stayed in the cabins since around mid-June. They have advised the parties to seek immediate medical attention if they develop symptoms of hantavirus, which starts out exhibiting flu-like symptoms that include headache, fever, aching muscles, shortness of breath with coughing and eventually severe breathing difficulties and death, according to the CDC.
"Early symptoms include fatigue, fever and muscle aches, especially in the large muscle groups - thighs, hips, back, and sometimes shoulders. These symptoms are universal," says the agency, on its website.
No cure, but early identification is crucial
Park officials say nearly four million people visit a year. Yosemite is one of the country's most popular vacation destinations, with most visitors attracted to the park's scenic views and hiking trails. About 70 percent of all visitors congregate in Yosemite Valley, where Curry Village sits.
Due to the small number of hanavirus cases, the precise incubation period is not known, says the national health agency. Other experts put the period at between two and four weeks following exposure, but that can include a range of just a few days to several weeks. More than one-third of all cases are fatal.
"Providers are reminded to consider the diagnosis of HPS in all persons presenting with clinically compatible illness and to ask about potential rodent exposure or if they had recently visited Yosemite National Park," said the CDC.
There is no cure for hantavirus, but health experts say early detection via blood tests can save lives.
HPS has never been found to be transmitted between humans.
"Early medical attention and diagnosis of hantavirus are critical," Yosemite superintendent Don Neubacher said in a statement. "We urge anyone who may have been exposed to the infection to see their doctor at the first sign of symptoms and to advise them of the potential of hantavirus."
The disease is reportedly carried in the feces, urine and saliva of deer mice and other rodents, and is carried on airborne particles and dust. You can contract the disease by inhaling the virus or handling infected rodents.