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What is hantavirus?

Hantavirus causes a condition in humans known as Hantavirus Pulmonary Syndrome, which is a severe respiratory illness requiring hospitalization. The disease is diagnosed through blood testing. Hantavirus is passed to humans when they inhale airborne particles released from the droppings and urine of infected rodents, specifically the deer mouse. Persons have also become infected after being bitten by rodents. The virus does not cause disease in pets and is not passed from pets to people or from one person to another. Acquisition of the virus from ingesting food or water contaminated with infected saliva, urine or faeces has not been demonstrated.

This disease was first recognized in the southwestern United States in May of 1993 when there was an outbreak of respiratory illness that killed a number of people. There have been 17 cases to date in Canada; 6 in British Columbia, 9 in Alberta and 2 in Saskatchewan. Hantavirus has been identified in deer mice in Ontario. This finding is not unexpected as the virus has been found to be present in deer mice in all provinces from British Columbia to Newfoundland. The deer mouse has a very broad distribution in North America, which includes all of Canada and the United States. The deer mouse is found in rural and semi-rural areas but generally not in urban centers. The deer mouse should not be confused with the more common house mouse, which is not known to carry hantavirus.

Hantavirus is not a new risk to public health and there is no evidence that it is increasing or spreading. All that is new is our ability to recognize it. In the US, special studies have confirmed that the disease has been present since 1970. Recent studies suggest that the infection is very rare even among workers who are continually exposed to rodent reservoirs of hantavirus. The virus has likely been in the deer mouse population for some time but only causes human illness in very rare and unusual circumstances. The presence of this virus in deer mice and the knowledge that other viruses and some bacteria can be spread through contact with all rodents make it important that certain precautions be taken when cleaning up or disposing of rodents and droppings.

What precautions can I take against hantavirus?

In your home or cottage you should get rid of existing rodents by reducing any potential food sources and nesting sites that may be used by rodents inside and outside within 33 m (100 ft).

1. You must try and get rid of rodents if they have been detected inside the home. Do so in well ventilated areas, by opening windows and doors, in order to help remove any aerosolized virus inside closed-in structures.

2. Openings into the home should be sealed, screened or otherwise covered and spring-loaded rodent traps should be set inside the home. Traps no longer in use should be disinfected by washing in a general household disinfectant, such as bleach, in 1:10 solution. Rodenticides may also be used with appropriate precautions.

3. Dead rodents should be removed using rubber or plastic gloves and placed in a plastic bag containing sufficient bleach solution to thoroughly wet the carcasses. The bag should then be sealed, buried, burned, or disposed of in household garbage.

4. Rubber or plastic gloves should be worn during clean-up of surfaces or household goods contaminated with rodent droppings or urine. Contaminated items, such as food, rodent nests, dead rodents, etc., should be soaked thoroughly with a disinfectant, placed in a plastic bag and disposed of as described above.

5. Floors should be mopped with a solution of water, detergent and disinfectant. Dirt floors should be sprayed with a disinfectant solution. Carpets can be disinfected with household disinfectants or by commercial-grade steam cleaning or shampooing. Do not vacuum or sweep floors or carpets.

6. If rodents have nested inside furniture and the nest is not accessible the furniture should be removed and burned.

7. Contaminated bedding and clothing should be laundered with hot water and detergent. Laundry should be machine dried on a hot setting or air dried in the sun.

8. Gloved hands should be washed in a general household disinfectant and then in soap and water before removing the gloves. Thoroughly wash hands with soap and water after removing gloves.

Farmers and tradesmen (electricians, plumbers or others who work in crawl spaces, barns, outbuildings, and grain storage areas) should take the following precautions.

1. Breathing protection should be used when entering areas where rodents have been. Wear paper or cloth breathing protectors (masks) if possible.

2. Wear protective clothing, shoes and gloves that can be disinfected or thrown away.

3. If you are cleaning barns, outbuildings or other grain storage areas where rodents are likely to live, wear rubber gloves, protective goggles, clothing that can be laundered or is disposable, and rubber boots. Disinfect all protective gear when finished.

4. Launder all clothing that is not disposable or soak them in disinfectant until they can be washed.

5. Trap rodents in outbuildings and barns, etc.

Campers and hikers should take the following precautions.

1. Avoid contact with rodents and rodent burrows.

2. Do not disturb rodent dens.

3. Do not use cabins or other rodent-infested shelters that have not been properly cleaned and disinfected.

4. Avoid pitching tents or placing sleeping bags near wood piles, garbage, places where rodents might live, or near rodent burrows.

5. Do not sleep on the bare ground. Use tents with floors or cover the ground under sleeping areas.

6. Keep food in rodent-proof containers.

7. Bury or burn garbage or dispose of trash in covered containers.

8. Use only bottled, filtered or chemically disinfected water.