Hantavirus

 

What is hantavirus infection?

 

Hantavirus infection is a rare but serious illness. Typical symptoms are flu-like and include fever, headache, nausea, vomiting, muscle aches, diarrhea, abdominal pain and shortness of breath. These symptoms can occur any time between three days to six weeks (usually occurring around 14 days) after exposure. Infection without symptoms is rare.

Exposure to hantaviruses can cause a rare, but often fatal, disease called Hantavirus pulmonary syndrome (HPS). HPS can progress rapidly into serious lung complications and include the following symptoms: abnormal fall in blood pressure; lungs fill with fluid and severe respiratory failure.

There have been 23 cases of Hantavirus reported in Saskatchewan since 1994, including four cases in 2004, one case in 2008, one case in 2010 and three cases in 2011.

 

How is hantavirus infection spread?

 

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

The virus can also be transmitted by:

• being bitten by a deer mouse or other infected rodent, if the skin is broken;
• touching 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 and this has never been reported in North America. Hantaviruses are not spread from pets or livestock. However, cats and dogs may bring infected deer mice into contact with humans.

 

What are the sources of infection of hantavirus and where is it found in Saskatchewan?

 

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 or in man-made structures such as wood piles or old cars. They may enter buildings when the weather turns colder.

 

What do deer mice look like?

 

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.

Deer mouse photo, courtesy of Public Health Agency of Canada

 

Are there areas of the province where the risks are higher?

 

Ongoing studies in Saskatchewan have detected hantavirus in deer mice throughout a wide area of southern Saskatchewan. Human cases have occurred in prairie, parkland and forested areas, but the most recent cases have been found in central and north western parkland areas.

 

Are there people at higher risk of acquiring the disease?

 

The disease can affect all ages and gender of people. People are at higher risk if they come into contact with mice, their droppings or nesting materials. Most the exposures of people are from cleaning out or demolishing enclosed or poorly ventilated buildings that have had mouse infestations (i.e. grain bins, sheds, barns, garages, ventilation systems, trailers, elevators, etc.) or cleaning equipment such combines or vehicles that have been in storage.

 

What can people do to minimize their risk of getting hantavirus?

 

Preventative measures include controlling rodents such as mice, cleaning out buildings before use and minimizing the exposure to mice and their droppings. This includes:

• Trapping and safe removal of mice, keeping them out of buildings, trailers and equipment, and eliminating food sources and hiding places for them.
• Properly cleaning and disinfecting rodent-infested cabins and other enclosed buildings before use, and
• Minimizing exposure to sources of infection by wearing personal protective equipment or avoiding coming into contact with mice, their nests or harbourage areas (i.e. woodpiles).

The Saskatchewan Ministry of Labour Relations and Workplace safety has developed a set of guidelines for preventing hantavirus in the workplace and for the public entitled “Hantavirus Disease: Guidelines for Protection Workers and the Public”. It is available at: