Public Health

Department of Health: Take Precautions Against Hantavirus
To help prevent hantavirus infection, Wyoming Department of Health officials are reminding Wyoming citizens to be mindful of rodent droppings as they clean garages, campers, cabins, hay stacks and barns this spring.
“Anything that puts you in contact with rodent urine, droppings, saliva or nesting materials can place you at risk for infection,” said Dr. Tracy Murphy, state epidemiologist at the Wyoming Department of Health. “Infected rodents shed the virus through urine, droppings and saliva. Hantavirus pulmonary syndrome (HPS) is transmitted to humans through a process called aerosolization. Aerosolization occurs when dried materials contaminated by rodent urine and feces or saliva are disturbed. Humans become infected by breathing in these infectious aerosols.”
According to the department’s Infectious Disease Epidemiology Program, rodent infestation in and around the home remains the primary risk for hantavirus exposure. Even healthy individuals are at risk for HPS infection if exposed to the virus, and about 30-40 percent of cases result in death. The deer mouse is the primary reservoir of the hantavirus that causes HPS in Wyoming.
“Since 1999, we have received a total of six reported cases of HPS,” said Clay Van Houten, chief of the Emerging Diseases Section. “Unfortunately, about half of those cases resulted in death.”
Van Houten continued, “Our investigations into these cases show a clear association between contact with rodent dropping and illness. Generally, the cases had contact with rodent droppings while they were cleaning their barns and garages, moving hay bales that were infested with mice or cleaning their cabins.”
“Proper cleanup of rodent-infested areas is the key to preventing infection,” said Dr. Brent Sherard, Wyoming Department of Health director. Dr. Sherard offered the following guidelines:
• During cleaning, wear rubber, latex, vinyl, or nitrile gloves.
• Spray rodent urine and droppings with a disinfectant or bleach solution until thoroughly soaked. The bleach
solution can be made by combining 1 ½ cups of household bleach with 1 gallon of water.
• To avoid generating potentially infectious aerosols, do not vacuum or sweep rodent urine, droppings,
nesting materials or contaminated surfaces until they have been disinfected.
• Use a paper towel (while wearing gloves) to pick up the urine and droppings. Place the paper towel in the
garbage.
• After the rodent droppings and urine have been removed, disinfect items that might have been
contaminated by rodents or their urine and droppings:
--- Mop floors with a disinfectant or bleach solution.
--- Disinfect countertops, cabinets, drawers and other durable surfaces with a disinfectant or bleach
solution.
--- Spray dirt floors with a disinfectant or bleach solution.
--- Disinfect carpets with a disinfectant or with a commercial-grade steam cleaner or shampoo.
--- Steam-clean or shampoo rugs and upholstered furniture.
--- Launder potentially contaminated bedding and clothing with hot water and detergent. Use rubber, latex,
vinyl or nitrile gloves when handling contaminated laundry. Machine-dry laundry on a high setting or hang it
to air dry in the sun.
--- Leave books, papers and other items that cannot be cleaned with a liquid disinfectant or thrown away,
outdoors in the sunlight for several hours, or in an indoor area free of rodents for approximately one week
before cleanup. After that time, the virus should no longer be infectious. Wear rubber, latex, vinyl or
nitrile gloves and wipe the items with a cloth moistened with disinfectant.
--- Disinfect gloves before removing them with disinfectant or soap and water. After removing the gloves,
thoroughly wash bare hands with soap and warm water.