LOS ANGELES, CA (Catholic Online) - Park officials say that all four visitors stayed in Curry Village, a collection of tents and cabins at the eastern end of Yosemite Valley, over a one-week period in June.

Officials are now contacting everyone who has stayed in the tent cabins since that time to warn them about the virus. They're being advised to seek medical attention if they have any symptoms of infection.

"This is being taken very seriously," park spokesman Scott Gediman says. "We've been able to isolate the cabin area, we've done the thorough cleaning, we're monitoring the area, and we're trapping mice and testing them. We're making sure the cabins are shored up. We're being very active, and we have been since the cases came to light."

A Hantavirus is a rare viral infection carried by mice and is typically passed to humans by the rodents' feces and/or urine. People infected with the virus suffer flu-like symptoms at first, such as fever, headache and muscle pains in the thighs, back and hips. Two to seven days later, many patients have severe difficulty breathing -- and can die.

More troublesome is that fact that patients may not develop symptoms until one to six weeks after exposure. There is no cure or virus-specific treatment for Hantavirus.

A 37-year-old Alameda County man who died late last month was the first reported victim. The second victim was a woman from Southern California who managed to survive the infection. The third victim was a man from out of state who died in July.

There is no immediate information available on the fourth victim, who is expected to live. Public health officials are waiting for lab tests to confirm that the fourth victim has Hantavirus, but given the symptoms it's likely that patient also contracted the virus in Yosemite.

Since Hantavirus is a rare disease that can be difficult to diagnose, it's possible other victims may still be found. The two newest cases were reported to California public health officials only last weekend, although both victims had been symptomatic for weeks.

All four patients stayed in Curry Village's "signature tent cabins" over a one-week period in mid-June. Curry Village has 408 tent cabins with wood frames and canvas sides; 91 of those cabins are higher-end, with more insulation and other amenities.

Park officials have responded by revamping the existing cabins. "They're doing everything they can to eliminate areas where mice can get into the cabins," Gediman said. "This was never because the cabins were dirty; it was never because we didn't take care of them. This is just because approximately 20 percent of all deer mice are infected with Hantavirus. And they're here in Yosemite Valley."

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