Wider Warning After 3rd Yosemite Hantavirus Death - New York Times

After the death last week of a third person exposed to the deadly mouse-borne hantavirus, public health officials were expanding their warning to include more than 22,000 visitors to Yosemite National Park.

The latest victim, a West Virginia man, visited Yosemite in July. His death was confirmed on Thursday.

So far, eight people who visited the 1,100-square-mile park in California this summer have been infected. Three have died, while the five others are recovering, park officials said in a statement. Of the confirmed cases, six people are from California, one from Pennsylvania and one from West Virginia, according to the National Park Service.

Investigators initially focused their attention on cabins in the park’s Curry Village sections, where seven of those infected had stayed before falling ill. They sent e-mails and letters to more than 10,000 guests who stayed or had reservations in the cabins from June 10 through September.

When they discovered that an eighth person who fell ill had visited a different area of the park, the High Sierra Camp, health officials sent alerts to an additional 12,000 visitors, park officials said.

That eighth person camped in the wilderness in the park’s high country and stayed in a tent cabin at the Tuolumne Meadows Lodge, according to park officials. His symptoms were mild, the officials said, but after he learned of the outbreak he went to a local hospital, and laboratory tests confirmed he was infected. He is expected to make a full recovery, the officials said.

There is no known cure for the hantavirus. Since the disease was first discovered in the United States in 1993, there have been 602 reported cases of infection, resulting in 216 deaths, giving it a mortality rate of 36 percent.

Dr. Pierre Rollin, one of the lead investigators for the Centers for Disease Control and Prevention helping in investigating the outbreak, said that the virus itself was the same as had been seen in past years.

“What is unusual is to have an outbreak concentrated in one area like this,” he said.

Hantavirus is common in deer mice. A survey by the California Department of Public Health in 2010 found that 18 percent of the mice tested in Yosemite carried the virus.

However, transmission to humans remains rare. A person can be infected if they come into contact with the feces or urine of mice carrying the virus.

The type of hantavirus in the United States is not believed to be transmissible from person to person.

People infected with the virus generally begin to show symptoms one to five weeks after exposure, according to the C.D.C.

Early symptoms include “fatigue, fever and muscle aches, especially in the large muscle groups â€" thighs, hips, back and sometimes shoulders,” according to the C.D.C.

“There may also be headaches, dizziness, chills and abdominal problems, such as nausea, vomiting, diarrhea and abdominal pain,” according to the agency.

In as little as four to 10 days, the symptoms can become more severe. Patients can suffer shortness of breath and coughing as the lungs fill with fluid. The C.D.C. Web site quotes one survivor as saying that it felt as if he had a “tight band around my chest and a pillow over my face.”

Park officials at Yosemite have set up a hot line for visitors concerned that they may have been exposed. Since the first warnings were issued, it has been flooded with thousands of calls.

Health officials warned that more infections could be reported. Some four million people from around the world visit the park each year.

The outbreak prompted the World Health Organization to issue a global alert of its own for travelers to any country to avoid exposure to rodents.

Dr. Rollin said that doctors in other countries were investigating possible infections, but no one was confirmed to have the virus.

Despite the lack of a cure, Don Neubacher, the superintendent of Yosemite, said in a statement that it was important for people who think they might have been infected to get medical care.

“We want to make sure that visitors have clear information about this rare virus and understand the importance of early medical care,” he said. “We continue to work closely with state and national public health officials, and we urge visitors who may have been exposed to hantavirus to seek medical attention at the first sign of symptoms.”