Hantavirus

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About hantavirus
Symptoms and treatment
Rodent exclusion
Safe cleaning practices
Hantavirus activity in San Diego County
More information

In San Diego County, deer mice are the main carriers of a hantavirus called Sin Nombre virus. Sin Nombre virus can make people sick but is not spread person to person. Deer mice are mostly found in rural areas, the desert, and mountains. Mice that commonly live with humans are house mice and do not carry hantavirus. However, you should avoid contact with all wild rodents because they may carry other diseases.The type of rodents that can transmit Andes virus have not been found in the county.

You can reduce your exposure to hantavirus by:

• Excluding rodents from homes, cabins, sheds, and other structures
• Airing out unused structures before entering
• Using a wet cleaning method and other safe cleaning practices (described below) 

The Vector Control Program routinely collects blood samples from wild mice to test for hantavirus. If positive results are found, the public is notified of appropriate precautions to take to lower risk of exposure.

Rodent exclusion

Keep rodents from entering homes, cabins, sheds, and other structures:

• Seal all entry holes large enough for mice (dime-size or larger)
• Cover or put away pet food dishes when not in use
• Store pet food in rodent-proof containers
• Cover all trash cans with rodent-proof lids
• Use mouse traps where there is evidence of mouse activity
• Remove woodpiles, old cars, trash, and debris from property
• Store hay or firewood at least 100 feet away from buildings
• Cut grass, weeds, and trim bushes within 100 feet of buildings

More rodent exclusion tips

Safe cleaning practices

Lower your exposure to airborne particles when cleaning up rodent droppings:

• Air out unused rooms or buildings that have been empty for a long period of time. Leave doors and windows open for 30 minutes
• Wear latex or rubber gloves and protective respiratory equipment, such as a face mask
• DO NOT stir up dust by sweeping up or vacuuming rodent droppings, urine, or nesting materials
• Instead, use the WET CLEANING method:
  1. Make a disinfectant solution (10 parts water to 1 part bleach) or use a commercial disinfectant making sure to follow the label instructions
  2. Spray the disinfectant solution on polluted areas, including dead rodents or droppings, and let sit for 15-20 minutes before cleaning
  3. Soak sponges in the disinfectant solution and clean
  4. Place dead rodents, nesting material, and all cleaning supplies in a sealed plastic bag and throw bag away immediately
  5. After cleaning, wash your gloved hands, remove the gloves and dispose of them, and then wash your bare hands as well

Hantavirus activity in San Diego County

We routinely collect blood samples from wild mice to test for hantavirus. On average, about 3% of mice sampled test positive for hantavirus each year. 

Positive test results are posted below for the current year.

Current Activity

Historical hantavirus activity

More information

Press Releases
Hantavirus Brochure (Also available in Spanish and other languages)
"The Airborne Menace" Hantavirus Video
CDC Hantavirus Webpage

Questions?

  858-694-2888

  vector@sdcounty.ca.gov