More than 1,000 calls a day are coming into Yosemite National Park as visitors frightened about a growing outbreak of a deadly mouse-borne virus flood phone lines seeking reassurance.
At least six rangers, and often more, are staffing phones this week to answer questions from visitors wondering whether they're in danger of exposure to hantavirus pulmonary syndrome, park spokesman Scott Gediman said.
"We're reaching out and they are reaching out to us, and we are trying in every way shape and form to be transparent and forthright," he said. "We want to tell people this is what we know. The most important thing is the safety of park visitors and employees."
On Thursday the California Department of Public Health confirmed that a total of six people have contracted the disease at Yosemite, up from four suspected cases earlier in the week. Two of those people have died from the illness that can cause rapid acute respiratory and organ failure.
Alerts sent to state and county public health agencies, as well as local doctors and hospitals, have turned up other suspected cases that have not yet been confirmed, according to the Centers for Disease Control and Prevention.
"Additional suspected cases are being investigated from multiple health jurisdictions," the CDC said in an advisory issued to health care providers.
The illness can take six weeks to incubate. There is no cure, and anyone exhibiting the symptoms must be hospitalized. More than 36 percent of people who contract the rare illness will die from it.
All of the victims confirmed so far stayed in insulated "Signature" tent cabins in the park's historic Curry Village section between mid-June and early July. The victims' cabins were within about 100 feet of each other, park officials said.
Park concessionaire Delaware North Co. sent letters and emails this week to nearly 3,000 people who stayed in the affected area between June and August warning them that they might have been exposed. It tells them to seek treatment if they exhibit symptoms: chills, fever, gastric problems and muscle ache, followed rapidly by difficulty breathing.
At least 7,000 people stayed in other "Signature" cabins separate from the outbreak area during the same period, the CDC said.
Park officials worked quickly to disinfect all 400 of the Curry Village cabins when the outbreak first was detected earlier this month. When the outbreak was narrowed to the 91 double-walled insulated cabins, the California Department of Public Health ordered them shut down Tuesday.
Park officials said the double-walled design of those particular cabins made it easy for mice to nest between the walls. The disease is carried in the feces, urine and saliva of deer mice and other rodents and carried on airborne aerosol particles and dust.