A second fatality from hantavirus pulmonary syndrome (HPS) was announced Monday by the National Park Service Office of Public Health and Yosemite officials. Three cases linked to Yosemite visits have been confirmed in the past two weeks and two of those people died from HPS. A probable fourth case has also been reported.

The first victim was 37-year-old male from Alameda and the second fatality was an out-of-state adult male.

The news of the second death has prompted Yosemite to ramp up its public health response and outreach.

All four people visited Yosemite in June and might have been exposed while vacationing in one of the 91 "Signature Tent Cabins" at Curry Village.

The cabins have thoroughly cleaned and disinfected and are currently still open to the public. All visitors to the park, including those with tent cabin reservations, are being advised of the situation.

Park Ranger Jana McCabe said all people with tent cabin reservations are being told that if they see rodent droppings, to alert park officials and to not attempt to clean up themselves.

An outreach effort is currently underway by the park concessionaire, Delaware North Company, to contact visitors who stayed in the tent cabins from mid-June through the end of August. Doctors of the two victims learned of the virus from advisory earlier distributed by the Center for Disease Control.

National Park Service health officials, including Director Jon Jarvis and Regional Director Chris Lehn from Washington have arrived at the park to help with distributing clear and accurate information about hantavirus. As of Tuesday, 1,700 visitors had been contacted who had stayed in the affected area over the past eight weeks. These individuals are being informed of the recent cases and are being advised to seek immediate medical attention if they exhibit any symptoms of hantavirus.

The park and concessionaire have also increased public education efforts geared towards visitors and park employees that includes distributing information to all visitors entering the park, information at Curry Village registration area, and notifications throughout the park.

Early medical attention is critical for individuals who contract hantavirus, a rare but serious disease. Symptoms of the disease are fever and aches, but can progress rapidly to life-threatening illness.

Hantavirus is not contagious and can not be passed from an infected person to another person.

Yosemite has set up a non-emergency phone line for all questions and concerns related to hantavirus in the park. The phone number is (209) 372-0822 and is being staffed daily 9 a.m. to 5 p.m.

"The health of our visitors is our paramount concern and we are making every effort to notify and inform our visitors of any potential illness," said park Superintendent Don Neubacher. "Because people often don't get sick from hantavirus until one to six weeks after exposure, we are encouraging anyone who stayed in Curry Village since June to be aware of the symptoms of hantavirus and seek medical attention at the first sign of illness."

HPS is caused by a virus that individuals get through contact with the urine, droppings or saliva of infected rodents, primarily deer mice. Most infections are caused by breathing small particles of mouse urine or droppings that have been stirred up into the air.

According to McCabe, it is estimated that 20% of deer mice in the Sierra Nevada are infected with hantavirus, the same percentage estimated for mice found in New York City.

If the virus is contracted, the symptoms appear one to six weeks after exposure with fever, headache, and muscle ache, and progresses rapidly to severe difficulty in breathing and, in some cases, death. Early medical attention can greatly increase the chance of survival, so it is important to seek medical attention immediately if an individual experiences any of these symptoms and may have been exposed to rodents.

The park has conducted additional rodent trapping and is increasing rodent-proofing and trapping measures in tent cabins and buildings throughout the park.

Since HPS was first identified in 1993, there have been about 60 cases in California and 587 cases nationally. About one third of HPS cases identified have been fatal.

According to park officials, Yosemite has been linked to two other hantavirus cases, one in 2000 and one in 2010. In those cases the people had stayed in tent cabin in Tuolumne Meadows and both people recovered.

Individuals can take the following steps to prevent contracting HPS:

Avoid areas, especially indoors, where wild rodents are likely to have been present.

Keep food in tightly sealed containers. .

Keep rodents out of buildings by removing stacked wood and rubbish piles from around homes and sealing any holes where rodents could enter.

When cleaning a sleeping or living area, open windows to air out the areas for at least two hours before entering. Take care not to stir up dust. Wear plastic gloves and spray areas contaminated with rodent droppings and urine with a 10% bleach solution and wait at least 15 minutes before cleaning the area. Place the waste in double plastic bags and discard. Wash hands thoroughly afterward.

Wear gloves when handling dead rodents. Spray dead rodents with a disinfectant and dispose of them.

For additional information on preventing HPS, visit the federal Centers for Disease Control and Prevention's Hantavirus Web site page.