A second person has died from a rare virus after camping at Yosemite National Park, according to park officials.
The camper, whose name and gender have yet to be released, died 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 at least three other campers are thought to have acquired the virus this summer. Two of the four known cases have been fatal.
Park officials are warning 1,700 past campers that they might have been exposed to virus, The Associated Press reported.
"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," park superintendent Don Neubacher said in a statement, explaining how the flu-like symptoms of hantavirus pulmonary syndrome can take up to six weeks to appear. "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."
Early symptoms include fatigue, fever, chills, muscle aches and headaches as well as stomach pain, nausea and diarrhea, according to the U.S. Centers for Disease Control and Prevention. But in less than 10 days, those symptoms give way to coughing and shortness of breath as the lungs fill with fluid.
"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."
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 CDC. In rare cases, it has also been transmitted through rodent bites. Hantavirus cannot pass from person to person through touching, kissing or blood transfusions.
Since it was first identified in 1993, fewer than 600 cases of hantavirus pulmonary syndrome have been reported nationwide, more than a third of which have been fatal, according to the CDC.
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.
Hantavirus has been detected in deer mice at the Curry Village Campground, according to park officials.
This is not the first time hantavirus infections have been linked to Yosemite National Park. Two campers became ill in 2000 and 2010 but survived, the AP reported.
The park is now warning campers to take extra precautions to protect themselves by, among other things, airing out sleeping areas before entering and keeping food in tightly sealed containers.