Hantavirus Pulmonary Syndrome, or HPS, is a severe illness that is caused by a virus called hantavirus which is carryied by deer mice. This rare disease was first identified in the southwestern United States in 1993.
Although the virus has been present for a long time, it has been recognized recently.
HPS was first found in Canada in 1994, when 3 cases were reported in British Columbia.
Since then about 50 more cases have been found, mostly in the western provinces of Manitoba, Saskatchewan, Alberta and British Columbia.
The disease is considered to be extremely rare - only about 400 cases have been reported in all of the United States and Canada
The deer mouse is commonly found in fields of rural and semi-rural areas of B.C., they usually nest in hollows around trees roots or rocks.
Its fur's colour varies from golden brown to pale grey with white chest and legs. They have noticeable big eyes, long round ears and long whiskers as well as four toew on the forefeet and five toes on the hind feet.
Adults mice weigh between 10 to 35g and mesure approximatively 170mm (including the tail). They have in average four litters of 2 to 9 youngs per year.
The deer mouse is omnivorous, its diet includes seeds, plant greens, berries, nuts, mushrooms, and insects; they also like gnawing on bones or antlers in order to get calcium.
Their predators include: weasels, skunks, minks, bears, coyotes, wolves, owls, foxes, snakes and raccoons.
TRANSMISSION OF THE DISEASE:
Hantavirus is spread by breathing in mice droppings, urine or nesting materials. The only mice involved are deer mice (Peromyscus maniculatus). Occasionally, it can be spread through small breaks in the skin when handling a wild mouse, or by mouse bites. There is no confirmation whether or not Hantavirus can be spread from one person to another.
People living in areas where the virus is present may be at risk of catching it from close contact with wild mice. Fortunately the risk of catching the disease is very low.
Campers and hikers are at risk when using infested trail shelters or camping in deer mouse habitats. Anybody working, doing activities or living in closed spaces where there is a high population of deer mice are at greater risk. Precautions should be taken near vacant buildings even if you don't see any mice.
SYMPTOMS:
Hantavirus Pulmonary Syndrome starts with flu-like symptoms (fever, sore muscles, headache, nausea, vomiting and shortness of breath). As the disease gets worse, fluid builds up in the lungs, which makes it harder to breathe.
Symptoms could develop from one to six weeks following the exposure, with an average of from two to three weeks. Once the initial symptoms appear, the disease can progress rapidly and become life-threatening within a few days.
In North America one person out of three carrying HPS have died.
TREATMENT:
The British Columbia Ministry of Health affirms that there is currently no cure or treatment for HPS, but most of the symptoms and complications can be treated through hospitals' intensive care.
The treatment will be mainly supportive, for example: using assisted mechanical breathing (mechanical ventilation) and maintaining fluid and electrolyte balance and blood pressure.
AVOIDING MICE:
When hiking or camping, avoid mice and try not to disturb rodent burrows, always use a ground cover or a tent with a floor. Don't use cabins where there are mouse or rat droppings. Keep your food in rodent-proof containers.
Avoiding contact with mice and their droppings as well as controlling rodents in and around the house are the best ways to prevent Hantavirus Pulmonary Syndrome infection. Remove any cluster within 35 meters of your home that could be used by mice as a shelter: thick bushes, garbage, and woodpile
Make sure there are no holes in your walls, roof and other places that could let mice inside the house. Always wash your hands after touching any rodents or their droppings.
It is also important to learn how to clean up safely a place inhabited by rodents: the Ministry of Health gives use full instructions to clean up an infected area, they also emphasizes on how to dispose safely of dead mice: http://www.bchealthguide.org/healthfiles/hfile36.stm
Important Note: the British Columbia Ministry of Health advises to contact your public health office before cleaning up the home of someone who has HPS.
