Spring Cleaning Danger: The Hantavirus Risk Lurking in Your Cottage

TORONTO, ON – May 06, 2026 – For thousands of Canadians, the May long weekend marks the unofficial start of summer—a time for dusting off the deck chairs, firing up the barbecue, and opening the cottage for the season. But as property owners return to their seasonal retreats, a hidden danger may be lurking inside: a rare but potentially fatal virus carried by common rodents.

As the spring thaw gives way to cottage season, pest control experts are issuing a critical public health warning. Abell Pest Control, a firm with a century of experience in the field, is urging caution before airing out cabins, sheds, and garages that have sat dormant all winter. These quiet, sheltered structures are ideal nesting grounds for rodents, some of which can carry hantavirus.

“Many Canadians are unaware that hantavirus is a potential risk in seasonal properties and outbuildings across the country,” said Aaron Soudant, Director of Service Excellence and Quality Assurance at Abell Pest Control, in a recent advisory. “Opening cottages, cabins, sheds, or other areas with signs of rodent activity should always be approached carefully. The good news is that hantavirus exposure is preventable when proper cleaning and safety procedures are followed.”

The Invisible Threat in Dusty Corners

Hantavirus Pulmonary Syndrome (HPS) is a severe respiratory illness transmitted from rodents to humans. The primary carrier in Canada is the ubiquitous deer mouse (Peromyscus maniculatus), a species commonly found in the rural and wooded areas where cottages are often located. While other rodents like the white-footed mouse can also be carriers, the deer mouse is the main culprit behind the Sin Nombre virus, the strain of hantavirus that causes HPS in North America.

The virus is shed in the rodents' droppings, urine, and saliva. The greatest risk of transmission occurs not from seeing a mouse, but from cleaning up the mess it leaves behind. When dried droppings or nesting materials are disturbed by sweeping, vacuuming, or dusting, tiny virus particles can become airborne. Inhaling these invisible particles is the most common route of infection. Exposure can also happen by touching a contaminated surface and then touching your eyes, nose, or mouth.

Symptoms typically appear one to six weeks after exposure and begin with flu-like signs: fever, muscle aches, headaches, and fatigue. However, the disease can rapidly progress to the lungs, causing severe shortness of breath and respiratory failure. There is no specific cure or vaccine for HPS, and treatment involves supportive care in a hospital, often in an intensive care unit.

A Rare Disease with Severe Consequences

While the risk of contracting hantavirus is low for the general population, its severity cannot be overstated. Since surveillance began in Canada, there have been 168 confirmed cases as of May 2026. Though the numbers are small, the case fatality rate is alarmingly high, hovering between 30% and 40% in North America—meaning nearly one in three people who contract the severe form of the disease do not survive.

The vast majority of cases in Canada have occurred in the western provinces of British Columbia, Alberta, Saskatchewan, and Manitoba, where deer mouse populations carrying the virus are more established. Alberta has recorded the highest number of cases, while Saskatchewan health officials issue annual warnings to farmers and cottagers. British Columbia has seen a mortality rate as high as 44% among its confirmed cases.

Interestingly, while deer mice infected with hantavirus have been found in Northern Ontario, Public Health Ontario reports no human cases of HPS have ever originated in the province. Only one case has been reported east of the prairies, in Quebec. Researchers suggest this may be due to genetic differences in the virus strains found in Eastern Canada, which appear less likely to cause severe disease in humans. Nonetheless, the presence of the virus in local rodent populations means the potential for risk exists, and precautions are warranted everywhere.

A Practical Guide to a Safe Spring Opening

The most dangerous moment for exposure is during the initial spring cleaning. Before you start, a careful inspection is crucial. Look for tell-tale signs of a winter rodent infestation: small, dark droppings along baseboards and in cupboards; shredded paper, insulation, or fabric for nesting; and gnaw marks on food packaging or wooden structures.

If you find evidence of rodents, Health Canada and pest control experts strongly advise against sweeping or vacuuming the area dry. Instead, follow these methodical steps for safe cleanup:

1. Ventilate the Area: Before entering, open all doors and windows to air out the space for at least 30 minutes. Leave the area while it airs out to allow airborne particles to dissipate.

2. Wear Protective Gear: Protect yourself by wearing non-porous rubber or latex gloves. In poorly ventilated or confined spaces with heavy infestation, a HEPA-filtered respirator or an N95-rated mask is highly recommended to prevent inhaling viral particles. Goggles can provide additional protection for your eyes.

3. Soak, Don't Sweep: Prepare a disinfectant solution by mixing 1 part household bleach with 9 parts water. Generously spray the droppings, nesting materials, and any dead rodents with the solution until they are thoroughly soaked. Let it sit for at least 10 minutes to neutralize the virus.

4. Wipe and Dispose: Use paper towels to wipe up the disinfected materials. Place the used paper towels and waste in a heavy-duty plastic bag. Seal the bag tightly, then place it inside a second bag and seal it as well. Dispose of the bag in your regular trash, according to local regulations.

5. Clean the Entire Area: Mop floors and wipe down countertops, cupboards, and any other surfaces that may have been contaminated using the same bleach solution.

6. Final Cleanup: Once finished, wash your gloved hands with the disinfectant or soap and water before taking the gloves off. After removing the gloves, wash your bare hands thoroughly with soap and warm water.

Long-Term Prevention Strategies

Effective cleanup is essential, but preventing rodents from getting inside in the first place is the best long-term solution. After your initial opening, take time to rodent-proof your property for the seasons to come.

Inspect the exterior of your cottage, shed, and garage for any holes or cracks. Mice can squeeze through openings as small as a dime (about ¼ inch or 6 mm). Seal any gaps you find with steel wool, wire mesh, or caulk. Ensure that food is not an attractant by storing all pantry items, including pet food, in sealed, rodent-proof containers made of metal or thick plastic. Keep the area around your property clear of clutter, tall grass, and woodpiles, which can provide shelter and nesting sites for rodents.

By taking these informed precautions, cottage owners can mitigate the risk of hantavirus and ensure their seasonal sanctuary remains a place of relaxation and rejuvenation, not a source of preventable illness.