Hantavirus

In western North America, deer mice (Peromyscus maniculatus) are the primary carriers of the particular strain of hantavirus that causes respiratory illness in people.

Deer mice are found throughout Saskatchewan in a variety of indoor and outdoor habitats. They are more common in rural and semi-rural areas than in urban areas. Deer mice construct nests in stumps, hollow tree cavities, under logs, abandoned bird nests, wood piles, old cars or buildings such as sheds, granaries, garages and cottages. They may enter buildings when the weather turns colder.

Compared to house mice or field mice, deer mice have relatively large eyes and ears, long tails and are bicoloured. The belly and underside of their body is white, and the back and upper part of their tail is dark brown or gray.

Humans are most often exposed to the virus when they breathe in air contaminated by deer mouse saliva, urine or feces containing infectious hantaviruses. This can occur, for example, after sweeping or vacuuming infected areas.

Other ways Hantavirus can be transmitted to people include:

• through bites of an infected deer mouse or other infected rodent;
• touching mucous membranes (e.g. eyes, mouth, nose) with hands or gloves that are contaminated with rodent urine, saliva, or droppings;
• eating food contaminated by infected deer mouse saliva, urine or droppings.

Hantaviruses are rarely, if ever, spread from person to person; this has never been reported in North America. Hantaviruses are not spread from livestock. Human cases have been associated with exposure to domestic (pet) rats. Cats and dogs may bring infected deer mice into contact with humans.

Exposure to hantavirus can be reduced by avoiding contact with rodents and contaminated airborne particles.

• Block openings that might allow rodents to enter a building;
• Store human and animal food, water and garbage in containers with tightly fitted lids;
• Be aware of animal droppings and nesting materials when cleaning a home or other building; and
• Move woodpiles or other potential hiding places for mice away from the home.

When cleaning rodent-infested areas, people are advised to avoid activities that raise dust, and prevent direct contact and inhalation of airborne virus.

• Ventilate the building by opening doors and windows for at least 30 minutes before cleaning;
• Use wet mopping methods and wear gloves;
• Wear goggles and a well-fitting N-95 type filter mask when cleaning areas contaminated by droppings;
• Dampen areas contaminated with rodent droppings with bleach disinfectant (1 part bleach to 9 parts water), let sit for 10 minutes and remove droppings with a damp mop or cloth;
• Avoid using dry cleaning methods such as dusting, sweeping, vacuuming or air-hosing; and
• After cleaning, wash gloves in disinfectant and hot soapy water before taking them off. Wash hands thoroughly.