Aug. 17, 2012 -- A California man has died from a rare virus he may have contracted in Yosemite National Park, according to officials from the California Department of Public Health.
The man, whose name has not been released, died in late July from hantavirus pulmonary syndrome, a flu-like disease spread to humans by exposure to rodent droppings and urine. He had been camping in the California park's Curry Village Campground, where hantavirus has been detected in deer mice.
"Nearly 40 percent of people who develop this syndrome die from it," said ABC News' chief health and medical editor, Dr. Richard Besser.
A woman from Southern California who camped nearby also contracted the virus but is recovering, The Associated Press reported.
Since hantavirus was first identified in 1993, fewer than 600 cases have been reported nationwide. Most people are exposed to the virus in their own homes, according to the National Institutes of Health. But campers might have a heightened risk because of close contact with forest floors and musty cabins.
"You'd want to keep your campsite clean and food-free to keep mice away," Besser said. "If you see mouse droppings in your cabin, that's probably not a good place to stay."
Like the flu virus, hantavirus can enter the body through the mouth and nose by breathing or ingesting in tiny particles of rodent feces, urine or saliva, according to the U.S. Centers for Disease Control and Prevention. In rare cases, it has also been transmitted through rodent bites.
Hantavirus cannot pass from person to person through touching, kissing or blood transfusions, according to the CDC.
The California camper would be the first person to die from the disease contracted in the park, although two others became ill in 2000 and 2010, the AP reported.
Hantavirus causes flu-like symptoms, starting with fever, body aches and fatigue, Besser said. But in four to 10 days, "the severe symptoms kick in: shortness of breath and coughing as the lungs fill up with fluid," he said.
People with flu-like symptoms who might have been exposed to rodents or their nests should see their doctor immediately, according to the CDC.
"There is no specific treatment, cure or vaccine for hantavirus infection," the CDC warns on its website. "However, we do know that if infected individuals are recognized early and receive medical care in an intensive care unit, they may do better."