Three Wild Mice Test Positive for Hantavirus

Source: County of San Diego Communications Office

Three wild mice collected in routine monitoring in Carlsbad have tested positive for hantavirus, prompting County officials to remind people they should never sweep or vacuum up after rodents if they find them in living spaces.

County officials said it was important for people to remember to use “wet-cleaning” methods instead of sweeping or vacuuming if they find evidence of rodents in homes, sheds, garages, cabins or other living spaces.

Hantavirus is potentially deadly, and people are exposed to it when the virus, shed by wild rodents in urine, feces and saliva, dries and stirred into the air and inhaled.

While hantavirus is common in San Diego County, people are unlikely to be exposed to the virus because the carriers, wild rodents, wild mice in particular, generally want to live and nest away from people.

Still, County officials said people should be careful to use wet cleaning methods, with bleach, disinfectants, rubber gloves and bags if they find rodent droppings or other signs that wild rodents have gotten into living spaces and they must clean.

The mice collected from an open space in Carlsbad included two harvest mice and one deer mouse.

There is no cure or vaccine for hantavirus. In 2019, 42 rodents collected in routine monitoring by County Vector Control tested positive for hantavirus.

Last month, two cactus mice collected in Santee and Valley Center tested positive for hantavirus. Twelve rodents have tested positive so far in 2020.

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.