3rd Yosemite visitor dies of hantavirus; 2 new cases reported

Two more cases of hantavirus infection have been linked to Yosemite National Park, one fatal and the other believed to have originated in the park’s high country, marking the first time the outbreak has been traced beyond the Curry Village campground.

Yosemite officials announced the two additional cases after health authorities confirmed them Thursday morning, park spokesman Scott Gediman said. The fatality was reported by the Kanawha-Charleston Health Department in West Virginia, which revealed few details about the victim except that the person visited the park “in recent months.”

Gediman said the victim stayed in one of 91 “signature tent cabins” in Curry Village in mid-June. Park officials have attributed seven of the eight cases of hantavirus pulmonary syndrome — three of which have been fatal — to the insulated signature tent cabins and warned that anyone who stayed there between June 10 and Aug. 24 was at risk.

But the other newly reported infection was linked to camps along the High Sierra Loop, a route in the park’s high country frequented by backpackers. Gediman said a Northern California man spent time in July at four spots along the loop: the Merced Lake, Sunrise and Vogelsang camps and the Tuolumne Meadows Lodge.

The man became sick after his visit but recovered on his own, Gediman said. He contacted his doctor after he heard about the outbreak; it was later confirmed that he had contracted the disease.

“This one’s an outlier,” Gediman said.

Now Yosemite officials are sending emails and letters to about 6,000 people who stayed in the High Sierra Camps and the Tuolumne Meadows Lodge this summer, Gediman said. The national Centers for Disease Control and Prevention has said that as many as 10,000 people stayed in the signature tent cabins between June 10 and Aug. 24.

Officials “thought very seriously” about closing the High Sierra Camps early — Sept. 17 is the last day they are available — but decided to keep them open after consulting with public health authorities, Gediman said.

The 91 signature tent cabins in Curry Village were cleared last week as crews cleaned and retrofitted them to fill gaps that allowed mice inside the insulated walls. They remain closed indefinitely.

Spread through urine, droppings or saliva of infected rodents, hantavirus takes one to six weeks before causing symptoms in humans, officials said. The disease generally is transmitted when people come in contact with an enclosed area that has been infested by mice.

The disease is rare — 587 cases were diagnosed nationwide from 1993 and 2011, of which about one-third were fatal, according to the CDC. Cases at Yosemite are more unusual. Public health authorities said they had not heard of more than one case of the disease in the same location within a year.

News of the outbreak has rattled visitors, who travel across the globe to the national park. Park rangers have fielded thousands of calls through an emergency hotline. The World Health Organization has issued a global alert, and the U.S. Department of Health and Human Services has notified 39 countries whose citizens were at risk.

French health authorities announced Thursday that they were investigating two possible cases of hantavirus pulmonary syndrome. Gediman said park officials were “certainly looking at some other cases.”

Officials from the California Department of Public Health and the CDC spent Thursday inspecting the High Sierra Loop camps, Gediman said, adding that more mice will be trapped and tested for hantavirus in the coming days.

Gediman emphasized that the Northern California man’s case was “outside of the envelope” and that authorities believe travelers who stayed at the Curry Village signature tent cabins remain at greatest risk.

“It does cause us concern,” he said.” But we don’t feel overall it changes things dramatically.”

kate.mather@latimes.com