CDPH Press release
SACRAMENTO – The California Department of Public Health (CDPH) reminds
individuals to take precautions when entering cabins, trailers and other buildings that
may be infested with rodents after the recent diagnosis of hantavirus pulmonary
syndrome (HPS) in a Northern California man.
“Hantavirus pulmonary syndrome is a rare, but often fatal disease spread by rodents,”
said CDPH Director and State Public Health Officer Dr. Karen Smith. “The chances of
getting the virus are greatest when entering or cleaning buildings, or other closed
spaces, where wild rodents are present.”
HPS is caused by a virus that individuals contract through contact with the urine,
droppings or saliva of wild rodents, 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 infection. The illness begins with fever, headache, and muscle aches and
progresses rapidly to severe difficulty breathing and, in some cases, death.
Since HPS was first identified in 1993, there have been 73 hantavirus infections in
California and 659 cases nationally. About 30 percent of HPS cases identified in
California have been fatal.
The most recent case occurred in a patient who was exposed to the virus in Mono
County. Most HPS cases have been exposed in the Sierra Nevada or Southern
California mountain areas. Prompt diagnosis and medical treatment increase an
individual’s chances of recovery.
To prevent HPS, CDPH recommends the following precautions:
Avoid contact with all wild rodents, their droppings, and nesting materials.
Before entering an enclosed area that may be infested with rodents, allow it to
air out for at least 30 minutes.
CALIFORNIA DEPARTMENT OF PUBLIC HEALTH
Do not dry sweep or vacuum areas that rodents have potentially
Surfaces that rodents may have contaminated with urine or droppings should
be made wet with a 10% bleach solution or a commercial disinfectant following
label directions before mopping up.
Promptly dispose of all cleaning materials when done, and thoroughly wash
hands and clothes.
Examine the outside of all buildings and seal any holes or other areas that
would let rodents get inside.
Store all food items securely in rodent-proof containers.
In addition to hantavirus, individuals in recreational areas should take precautions to
reduce exposure to plague, which is carried by other wild rodents, such as squirrels and chipmunks, and their fleas. Steps the public can take include:
• Never feed squirrels, chipmunks or other rodents and never touch sick or dead
• Avoid walking, hiking or camping near rodent burrows.
• Wear long pants tucked into socks or boots to reduce exposure to fleas.
• Spray insect repellent containing DEET on socks and pant cuffs to reduce
exposure to fleas.
• Keep wild rodents out of homes, trailers, and outbuildings and away from pets.
For additional information about preventing HPS, please visit CDPH’s webpage and the
U.S. Centers for Disease Control and Prevention’s Website. For information on plague,
visit this CDPH webpage.