Yosemite employees tested for hantavirus as probe continues
About 100 employees at Yosemite National Park were tested for hantavirus, public health officials said Thursday as they continued to investigate an outbreak of the rare, rodent-borne disease that killed three visitors.
Ninety-six employees underwent voluntary testing Wednesday as part of a pilot program that officials expect to offer to all Yosemite employees within the next month, National Park Service spokesman John Quinley said. The tests will also be available for employees of the park's concessionaire, Delaware North Cos. Parks & Resorts.
The goal, Quinley said, is for health officials to better understand the virus and determine whether employees had previously been exposed but not shown symptoms.
Of the nine cases traced to the park since mid-June, only visitors -- no employees -- were infected, officials said.
Spread through the urine, droppings or saliva of infected rodents, hantavirus 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 Centers for Disease Control and Prevention. 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.
The employees tested Wednesday answered questions about their work, potential exposure to the deer mice that carry hantavirus and knowledge of the disease, Quinley said. They also had blood drawn for testing.
The results will be shared individually with the employees and provided to public health authorities, Quinley said.
The park remains on alert following the outbreak, which rattled visitors and prompted worldwide notifications. The 91 "signature tent cabins" in Curry Village, to which eight of the cases were linked, remained closed indefinitely as officials determine whether cleaning and repairs are enough to keep mice out.
— Kate Mather
Photo: Cabins at Yosemite National Park. Credit: Los Angeles Times