The Washington State Department of Health reports that about 14% of deer mice tested in Washington have been infected with hantavirus. Deer mice usually live in rural areas of the state.
One to five residents of Washington get sick with hantavirus every year. One human case of hantavirus has been identified in the state so far in 2012.
The virus affects the lungs, and the infection can cause death in up to 50 percent of the people who develop symptoms.
The symptoms of hantavirus include fever, chills, muscle aches, and sometimes nausea, vomiting, and abdominal pain. The muscle aches are often severe. Persons with hantavirus develop coughing and shortness of breath from a few days to a week after onset of other symptoms, followed by respiratory distress.
Exposure to hantavirus comes from inhaling dust after disturbing deer mouse nests or breathing in closed spaces where they live. Deer mice spread the virus in their urine, saliva, droppings, and nesting materials. Person-to-person spread of hantavirus has not occurred in the United States.
To prevent hantavirus, the following steps are recommended:
- Keep mice away. Clear the area within 100 feet of your house of junk piles, debris, and other areas where mice will nest. Keep weeds, brush, and grass cut. Plug up, screen, or cover all openings in your house larger than ¼ inch wide. Use steel wool to plug holes around the base of buildings. Stack firewood, lumber, and hay 12 inches off the ground and as far away from the house as possible. Use snap traps to catch the rodents.
- Remove food sources. Store pet food, grains, and animal feed in covered containers. Use a trash can with a tight-fitting lid for kitchen garbage and food scraps.
- Clean up infested buildings. Air out infested buildings at least 30 minutes before entering. Wear rubber gloves when handling contaminated traps or mice. Do not dry dust, sweep, or vacuum. Wet mop with a disinfectant solution. Wet down nests and other contaminated material with disinfectant (1 cup bleach diluted in 10 cups water, or phenol-based cleaner, or other disinfectant) and discard the material by double-bagging it in zip-lock bags. Put it in the garbage.
If healthcare providers or the public have questions about hantavirus, contact Snohomish Health District Communicable Disease Surveillance and Response at (425) 339-5278, Monday through Friday, 8 a.m. to 5 p.m.