Mouse Tests Positive for Hantavirus

San Diego County, California - One western harvest mouse collected in routine monitoring in the Black Mountain Ranch area has tested positive for hantavirus, County environmental health officials said this week.

The discovery prompted County officials to remind people never to sweep up or vacuum up after rodents if they find them in their homes, garages, sheds or cabins. People should use “wet-cleaning” methods instead, to keep from potentially breathing in the virus and getting sick.

It is not uncommon to find hantavirus in wild rodents in San Diego County. This is the tenth detection this year and there were there were 25 detections in 2020.

The virus can cause deadly infections in people and there is no vaccine or cure. However people are rarely exposed to it because wild rodents tend to live away from people. People can be exposed to hantavirus when wild rodents shed the virus in their urine, feces and saliva, the matter dries, is stirred into the air and people breathe it in.

Because of that, County officials said people should never sweep or vacuum up if they find rodent nests or signs of rodents in their homes. If people must clean they should use “wet cleaning” methods — using bleach, disinfectants, rubber gloves and bags.

Here are tips for people to prevent being exposed to wild rodents and hantavirus, and how to use wet-cleaning methods.

Avoid Exposure to Hantavirus

  • Seal up all external holes in homes, garages and sheds larger than a dime to keep rodents from getting in.
  • Eliminate rodent infestations immediately.
  • Avoid rodent-infested areas and do not stir up dust or materials that may be contaminated with rodent droppings and urine.
  • Clean up rodent droppings and urine using the wet cleaning method described below.

Use “Wet-cleaning” Methods to Prevent Inhaling the Virus

  • Do not sweep or vacuum infested areas.
  • Ventilate affected area by opening doors and windows for at least 30 minutes.
  • Use rubber gloves. Spray a 10 percent bleach solution or other disinfectants onto dead rodents, rodent droppings, nests, contaminated traps, and surrounding areas and let the disinfectant stand for at least 15 minutes before cleaning.
  • Clean with a sponge or a mop that has been soaked in disinfectant.
  • Place disinfected rodents and debris into two plastic bags, seal them and discard in the trash.
  • Wash gloves in a bleach solution, then soap and water, and dispose of them using the same double-bag method.
  • Thoroughly wash your hands with soap and water.

For more information, contact the County Department of Environmental Health and Quality (DEHQ) at (858) 694-2888 or visit the DEHQ hantavirus web page.