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Two Californians contracted the rare hanta virus, possibly after being exposed to mouse droppings or urine while vacationing at Curry Village in Yosemite National Park. Shown here are scientists from the San Mateo County Mosquito Abatement District and Environmental Health drawing blood from San Bruno Mountain Deer Mice in 1998 to test for the virus.

A 37-year-old Alameda County man died and a Southern California woman is recovering after contracting the rare hantavirus, most likely after being exposed to mouse droppings or urine while vacationing at Curry Village in Yosemite National Park, health leaders said Thursday.

The two stayed in separate tent cabins in Curry Village in mid-June, and fell ill several weeks later.

The state health department informed park officials two days ago that tests revealed the hantavirus in mouse droppings there, said ranger Kari Cobb.

She noted that park employees have since scrubbed and inspected buildings and taken steps to limit entry points for rodents, things they do routinely.

"Visitors should not be afraid to stay here," Cobb said.

This marks the first death of someone believed to have contracted the hantavirus at Yosemite.

One person became infected in 2000 and another in 2010. Both survived. Cobb said they had stayed in Tuolumne Meadows.

People can become ill with the hantavirus through contact with the urine, droppings or saliva of infected wild mice. The most common means of infection is breathing small particles that have become airborne.

Symptoms typically develop one to six weeks after exposure and include fever, headache and muscle ache. Once victims become sick, they can rapidly develop difficulty in breathing, known as pulmonary syndrome, and in some cases die.

Since the hantavirus was first identified in 1993, 587 cases have been discovered nationally, including 60 in California. About one-third of the California cases were fatal.

People are typically exposed to the hantavirus in areas where deer mice live, especially at higher elevations and in the eastern Sierra Nevada region.

The latest two infections bring the total number of hantavirus cases in the state this year to four.

The man who died at the end of July was a resident of Alameda County, said Alameda County Health Department spokeswoman Sherri Willis. She declined to reveal more details because of federal privacy laws.

State health officials said the woman who is recovering is in her 40s and lives in the Inland Empire.

Sandy Kleffman covers health. Contact her at 510-293-2478. Follow her at Twitter.com/skleffman.

To Avoid infection
  • Keep food in tightly sealed containers.
  • Avoid areas where wild rodents are likely to be present.
  • Keep rodents away by removing stacked wood and rubbish piles and sealing holes where they could enter.
  • Take care not to stir up dust, and, if you clean your living area, air out the area for at least two hours before entering.
  • Spray areas contaminated with rodent droppings with a 10 percent bleach solution or other household disinfectant, and wait at least 15 minutes before cleaning the area. Place the waste in tightly sealed, double plastic bags and discard in the trash, then wash hands thoroughly.
  • Do not touch live rodents and wear gloves when handling dead ones. Spray dead rodents with a disinfectant and dispose of in the same way as droppings.
  • If large numbers of rodents exist in a home or other buildings, contact a pest control service.