The discovery of a harvest mouse that tested positive for hantavirus has prompted San Diego County vector control officials to remind people to be careful around rodents and to protect their homes from infestations.
The most common mouse found in urbanized areas, the common house mouse, does not carry hantavirus — but it is possible for people to come into contact with wild mice that can carry the potentially-deadly disease in San Diego County’s suburban and backcountry areas. The harvest mouse that tested positive was trapped in routine monitoring last week in the south Escondido-Poway area.
County Environmental Health Director Jack Miller said rodents rarely pose a threat as long as they remain in the wild, but that people should be very careful if they find them in their homes or on their properties.
“Keeping rodents out of your home is the best way to protect yourself from being exposed,” Miller said. “If a rodent carrying hantavirus nests in your house or in a shed, you can be exposed by coming into contact with their droppings or urine.”
Wild rodents, most notably deer mice, can carry hantavirus and shed it through their saliva, urine and feces. People can breathe in the virus if infected dust from droppings and nesting materials is stirred up and becomes airborne.
Hantavirus can cause a very dangerous disease — hantavirus pulmonary syndrome — which can begin with flu-like symptoms but can lead to severe breathing problems and even death in some cases.
Miller said the public should remember two important things. First, avoid coming into contact with rodents. Second, use “wet-cleaning” methods if you do come across a rodent nest and have to clean it.
How to Avoid Exposure:
- 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.
- 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 at (858) 694-2888 or visit DEH’s hantavirus web page.