FRESNO, Calif. – The rustic tent cabins of Yosemite National Park – a favorite among families looking to rough it in one of the nation’s most majestic settings – have become the scene of a public health crisis since two visitors died from a rodent-borne disease after overnight stays.
On Tuesday, park officials sent letters and emails to 1,700 people who stayed in some of the dwellings in June, July and August, warning them that they may have been exposed to the disease that also caused two other people to fall ill.
Those four people contracted hantavirus pulmonary syndrome after spending time in one of the 91 Signature Tent Cabins at Curry Village around the same time in June. The illness is spread by contact with rodent feces, urine and saliva or by inhaling exposed airborne particles.
After the first death, the park sanitized the cabins and alerted the public through the media that the cause might have been diseased mice in the park.
However, officials did not know for sure the death was linked to Yosemite or the campsite until the Centers for Disease Control determined over the weekend that a second visitor, a resident of Pennsylvania, also had died.
After every park tragedy, officials stress that Yosemite is a wilderness area and that with it come some dangers.
On Sunday night, health officials with the National Park Service sent out an alert asking public health authorities to be on the watch for more potential rodent-related cases of acute respiratory failure.
Yosemite receives 4 million tourists a year from around the world, and national park officials were trying to determine whether the warning should be expanded to include foreign countries.
We’re discussing whether to do that and how to do that, said Dr. David Wong, chief of the epidemiology branch of the National Park Service Office of Public Health.
The disease can incubate for up to six weeks before flu-like symptoms develop. It’s fatal in 30 percent of all cases, and there is no specific treatment. It is not spread human to human.
Wong said the Yosemite cases are unusual because hantavirus illnesses are most often isolated events.
We are seeing more than one person who got it in a narrow space and time, he said. It makes us wonder why, and those are questions we don’t have the answers to.
The National Park Service currently has assigned two epidemiologists to work in the park trapping rodents for testing. Additional studies are being done to determine whether the Yosemite rodent population is larger than normal after a record snowpack in 2011 provided ample water for the grass seeds that mice favor.
As the Labor Day weekend approaches, some people have canceled reservations at Curry Village.