Four more visitors to Yosemite National Park have tested positive for the hantavirus, bringing the total number of park visitors infected to six, the California Department of Public Health reported.
To date, the Hantavirus Pulmonary Syndrome has been confirmed in six persons who visited the park between early June and mid July. Five are California residents and one is a resident of Pennsylvania. The Pennsylvania patient and one California patient died, three have recovered and one is currently hospitalized, but improving. Four, including both fatalities, lodged in the "signature cabins" of the Boystown area of Curry Village, one lodged in an unspecified area of Curry Village, and one is still under investigation.
The six individuals infected are residents from the Sacramento region, San Francisco Bay area, Southern California and the one from Pennsylvania.
"CDPH is working closely with the National Park Service and the Centers for Disease Control and Prevention to further investigate the cluster of Hantavirus Pulmonary Syndrome cases in Yosemite and reduce the risk of other visitors becoming ill from this virus," said CDPH director, Dr. Ron Chapman. "CDPH is continuing to monitor cases of Hantavirus Pulmonary Syndrome in persons who visited Yosemite National Park."
On Aug. 28, per recommendations from CDPH, Yosemite National Park closed all tent cabins in the Boystown area indefinitely. The National Park Service has issued communications to guests who had stayed in the Boystown area between June 10 and Aug. 24, alerting them to the HPS concerns and recommending that they seek medical attention if ill.
HPS is caused by a virus that individuals get through contact with aerosolized urine, droppings or saliva of infected wild mice, primarily deer mice. Breathing small particles of mouse urine or droppings that have been stirred up into the air is the most common means of acquiring infection. The illness starts 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.
When you are in wilderness areas or places where mice are present, you can take the following steps to prevent HPS:
• Avoid areas, especially indoors, where mice are likely to have been present.
• Keep food in tightly sealed containers and store away from mice.
• Keep mice out of buildings by removing stacked wood, rubbish piles, and discarded junk from around homes and sealing any holes where mice could enter.
• If you can clean your 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 or other household disinfectants and wait at least 15 minutes before cleaning the area. Place the waste in double plastic bags, each tightly sealed, and discard in the trash. Wash hands thoroughly afterward.
• Do not touch or handle live mice and wear gloves when handling dead mice. Spray dead mice with a disinfectant and dispose of in the same way as droppings. Wash hands thoroughly after handling dead mice.
• If there are large numbers of mice in a home or other buildings, contact a pest control service to remove them.
A non-emergency phone line for questions and concerns related to hantavirus in Yosemite has been set up. Visitors with questions can call 372-0822. The phones will be staffed from 9 a.m. to 5 p.m. daily.