The worst appears over at Yosemite National Park where an unprecedented outbreak of Hantavirus Pulmonary Syndrome this summer sickened nine park visitors, killing three of them.
But many questions still remain. To help answer them, the California Department of Public Health has invited up 2,500 Yosemite National Park employees to undergo voluntary blood tests and interviews this week as a way to uncover clues in the nation’s first known "cluster" outbreak of Hantavirus Pulmonary Syndrome.
"There’s a lot we don’t know about this disease so we hope we can shed some new light on some aspect of it by focusing on the employee population," said Barbara Materna is chief of the Occupational Health Branch at the California Department of Public Health, which is conducting this week’s blood tests. "It’s just a unique opportunity to learn more about preventing this disease."
All but one of the Yosemite victims appears to have contracted the rodent-borne lung infection after staying in the Curry Village “signature” tent cabins, which authorities permanently closed on August 24.
Materna says the employee blood tests will indicate how many park employees, if any, may have been exposed to the hantavirus and now carry the antibody. What’s more, she said, a survey of employee work and living habits within the park may help determine how the workers avoided full-blown infections.
"Together between the blood test results and the questionnaires we hope to better understand the kinds of exposures that these employees have while they work in the park and how to best protect them," she said.
Hantavirus is typically spread to humans from the contaminated feces, urine and saliva of infected rodents – in this case, deer mice that are indigenous to Yosemite.
Materna said all park visitors who stayed in the Curry Village signature tent cabins this summer are now safely past the six-week maximum incubation period for Hantavirus Pulmonary Syndrome.