The respiratory disease, carried by deer mice (brown on top and white underneath, with relatively large ears, as opposed to the all-gray house mouse, with small ears, which does not carry the disease), is transmitted by inhaling contaminated dust in a mouse-infested area.
Colorado averages about four cases of hantavirus a year; last year, five cases and two deaths were reported.
“Now is the time when people begin cleaning out barns, garages, storage buildings, sheds, trailers or cabins that have been closed up all winter,” said Colorado Department of Public Health and Environment State Health Veterinarian Elisabeth Lawaczeck. She advised residents to “take precautions before beginning such work, particularly if there are mouse droppings and other signs of mice.
“Be particularly vigilant where there are mouse droppings and evidence that mice have been in and around the buildings or nearby wood or junk piles.”
Rodent proofing and control also should be done before extensive cleaning efforts, said Lawaczeck. Structures should be ventilated thoroughly; wet down any accumulation of dust and dirt, and mouse droppings with a mixture of bleach and water before cleaning.
“Vacuuming an area without first wetting it down will not provide the necessary protection,” said Lawaczeck. She further advised rodent-proofing by plugging holes and entry points where mice can get inside; eliminating food sources for rodents; and removing abandoned vehicles and wood, brush and junk piles where rodents hide.
Hantavirus, which in nearly half of all cases causes death, begins with a high fever, a headache, severe body aches and vomiting. The onset of symptoms starts between one to six weeks after exposure.
Initially, there are no respiratory symptoms present. “If, however, you develop a fever, headache and muscle pain within six weeks of exposure to deer mice, seek medical care immediately,” advised Lawaczeck. Because no effective treatment exists for the disease, prevention is the key to avoiding hantavirus.
Hantavirus prevention tips include:
Rodent-proof buildings by plugging holes or other mouse entryways; conducting year-round rodent control, using traps or poisons, or hire a professional exterminator; keeping indoor areas clean, especially kitchens; storing food in rodent-proof containers and proper disposal of garbage in sealed containers; removal of such rodent hiding places as wood, junk and brush piles; storing firewood at least 100 feet from the house; keeping vegetation around the house well-trimmed; using caution when cleaning out enclosed areas such as trailers, cabins, barns or sheds; opening doors or windows to provide good ventilation for 30-to-60 minutes before cleaning; avoiding the stirring up of dust by watering down areas of mouse infestation with a mixture of bleach and water (a mixture of one cup of bleach per gallon of water is recommended); a thorough soaking of potentially contaminated areas with the bleach mixture; using rubber gloves to pick up saturated waste, including nesting materials or dead mice; double-bagging of waste using plastic bags, with burial in an outdoor garbage can or landfill; disinfecting gloves with bleach and water before removing, and hand-washing afterwards.
In cases of severe infestation, or when ventilation and dust suppression are not possible, use of a rubber face mask equipped with a high efficiency particulate air (HEPA) filter is advised; people camping in rural areas should avoid sleeping on bare ground, and use tents or ground covers.
For more information call Montrose County Health and Human Services' Environmental Services Department, at 970/252-5000, or visit www.montrosecounty.net/index.aspx?NID=203.