HealthLink BC File #36, February 2012
Hantavirus Pulmonary Syndrome (HPS)
- What is Hantavirus Pulmonary Syndrome?
- What are the symptoms?
- Is there a treatment?
- How is it spread?
- Who is at risk of being exposed to the hantavirus?
- What activities put me at risk?
- How can I protect myself?
What is Hantavirus Pulmonary Syndrome?
Hantavirus Pulmonary Syndrome (HPS) is a severe disease caused by a virus called hantavirus.
Although the virus has been present for a long time, it has only been recognized recently in North America. This rare disease was first identified in the southwestern United States in 1993. HPS was first found in Canada in 1994. Since then a small number of cases have been found mostly in the western provinces of Manitoba, Saskatchewan, Alberta, and British Columbia.
The disease is considered to be very rare - only about 600 cases have been reported in all of the United States and Canada. The BCCDC has reported 0-3 in B.C. every year.
What are the symptoms?
HPS begins as a flu-like illness. In the early stage of the disease, a person may have a fever, sore muscles, headaches, nausea, vomiting, stomach ache, and shortness of breath. As the disease gets worse, fluid builds up in the lungs, making it harder to breathe. In North America, about 1 out of 3 people with HPS have died.
Is there a treatment?
Although there is no specific treatment, medication, or cure, many of the symptoms and complications of HPS can be treated. Most patients are admitted to intensive care in a hospital. Some patients may be given anti-viral drugs, medicine and IV fluids to maintain blood pressure and prevent shock.
How is it spread?
In North America, there is no evidence that the disease spreads from one person to another. In Canada, the virus has been found only in wild deer mice, which are found across North America. Hantavirus is mainly spread when mouse droppings, urine or nesting materials are moved, sending virus particles into the air where they can be breathed in. In rare cases, the virus may be spread from mouse bites or through small breaks in the skin when handling a wild mouse. Always wash your hands after touching any rodents or their droppings. Domestic pets are not believed to be a source of infection.
Who is at risk of being exposed to the hantavirus?
People who live in areas where the virus is present, and who come in close contact with the saliva, urine, droppings or nests of mice, may be at risk of catching the virus. However, the chances of this happening are extremely low. Rodent infestation in and around the home remains the main risk for contact with hantavirus.
Which activities put me at risk?
High-risk activities include cleaning unused buildings, housecleaning, and working on construction, utility and pest control. Workers can be exposed in crawl spaces, under houses, or in vacant buildings that may have mice.
Campers and hikers can also be exposed when they use infested trail shelters or camp in other deer mouse habitats.
The chance of being exposed to hantavirus is greatest when people work, play, or live in closed spaces where wild mice are currently living. However, many people who have contracted HPS reported that they had not seen mice or their droppings before becoming ill. Therefore, precautions should be taken even if you do not see mice or their droppings.
How can I protect myself?
The best ways to prevent infection from hantavirus is to avoid contact with rodents and their droppings by controlling rodents in and around the home. Keep mice out of your home and learn how to clean up safely. Contact your local public health unit before you clean up the home of someone who has HPS.
Remove mice from your home
Use spring loaded traps to remove rodents from buildings. Dispose of them in sealed, double plastic garbage bags. Bury garbage bags in a 0.5 - 1 metre deep hole, burn them or put them in the trash according to local by-laws. Disinfect the traps with a mixture of 1 part bleach and 10 parts water, after dead mice have been removed.
Stop mice from getting in your home
Reduce the amount of rodent shelter, such as thick bushes or wood piles, plus food or garbage within 35 metres of your home. Block all holes around the walls, windows, doors, and roof of your home.
Safely clean areas where mice have been
During clean-up, wear an appropriate, well-fitting filter mask, rubber gloves and goggles. These masks include NIOSH-approved 100 series filters, such as N100, P100, and R100 (formerly called HEPA filters), or a respirator with P100 cartridges. An N95 mask may also be used. A dust mask for insulating or painting is not the same as these filter masks, so should not be used. Filter masks are available at safety supply stores and some hardware and home building stores. Your local public health unit, WorkSafeBC or the Workers Compensation Board can provide more information about masks, their use and limitations.
Prevent stirring up dust when you are cleaning areas where mice have lived. This includes ventilating any enclosed area for 30 minutes and wetting down the area with household disinfectant before you start. Most general purpose disinfectants and household detergents are effective. A mixture of 1 part bleach and 10 parts water can also be used. Pour mixture carefully onto the area to avoid disturbing any virus present - do not use a sprayer.
Wipe up droppings, nesting materials and other waste with a paper towel and place in a plastic garbage bag. Do not sweep or vacuum.
Double bag the contents, seal the bags, and then bury, burn, or place the bags in the trash, according to local by-laws.
Clean floors, carpets, clothing and bedding, and disinfect counter-tops, cabinets and drawers that have been in contact with mice.
Wash rubber gloves with disinfectant or soap and water before removing them. Wash your hands with soap and water after removing gloves.
Avoid mice when hiking or camping
- Try not to disturb rodent burrows. Do not use cabins where there are mouse or rat droppings.
- Keep your food in rodent-proof containers.
- Do not handle or pet any rodents, even if they appear tame.
- Do not pitch tents or place sleeping bags in areas near rodent droppings, rodent burrows, or possible rodent shelters, such as woodpiles.
- If possible, do not sleep on the bare ground. Use a cot with the sleeping surface at least 30 centimetres (12 inches) above the ground or use tents with floors.
- Dispose of garbage according to local requirements.
- Use only bottled water or water that has been disinfected by filtering, boiling, chlorination, or iodination for drinking, cooking, washing dishes, and brushing your teeth.
For more information on how to control rats and mice, see HealthLink BC File #37 Getting Rid of Rats and Mice.
For more HealthLinkBC File topics, visit www.HealthLinkBC.ca/healthfiles/ or your local public health unit.
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