Hantavirus cardiopulmonary syndrome (HCPS or hantavirus) is a rare but severe illness caused by hantaviruses such as the Sin Nombre virus. These viruses are found in wild mice and transmitted to humans via exposure to rodents.
Hantaviruses belong to the Hantaviridae family of viruses that are found in rodents. These viruses are found in many parts of the world, and they can cause two different types of disease syndromes. One form of the disease, known as hemorrhagic fever with renal syndrome (HFRS) occurs with viruses found in Asia and Northern Europe. The other form of the disease, Hantavirus Cardiopulmonary Syndrome (HCPS), is observed in the Americas, including BC.
The most serious HCPS illness is caused by the Sin Nombre Virus (SNV).
SNV was first described in the southwestern United States in 1993. Subsequent studies showed that the virus had been present for a long time and was first discovered in the early 1990s. The first time HPS was found in Canada was in 1994, when three cases were reported in BC. Every year, zero to four cases are reported among BC residents, including travel-related cases of hantavirus. Cases also occur in other western provinces.
In Canada, the virus is found only in wild mice, specifically the deer mouse (Peromyscus maniculatus) which is widely distributed in North America. The mice shed the virus in their urine, droppings and saliva. When fresh rodent urine, droppings or nesting materials are stirred up, tiny droplets, or aerosols, containing the virus become suspended in the air. The main route of spread to humans occurs through breathing in (inhaling) the virus.
Although rare, the virus can also be transmitted through the bite of an infected mouse.
Domestic pets are not believed to be a source of infection.
In North America, there is no evidence that the disease spreads from person-to-person, although cases acquired through person-to-person transmission have been documented in other parts of the globe.
If you have been exposed to mice or their droppings, and you develop symptoms, speak to a health care provider or call 811 for advice. It is possible to be exposed to the virus and have mild symptoms or not get sick at all.
HPS begins as a flu-like illness. In the early stage of the disease, a person may experience:
- fever & chills
- muscle aches, especially in the thighs, hips, back, and sometimes shoulders
- fatigue
There may also be:
- headaches
- dizziness
- abdominal problems, such as nausea, vomiting, diarrhea, and stomach pain
Four to 10 days after the initial phase of illness, the late sign and symptoms of HCPS appear. These symptoms appear rapidly for severe cases and are characterized by:
- cough
- laboured breathing
- shortness of breath
- fast heart rate
- heart rhythm abnormalities
Severe cases of HCPS can cause leaky blood vessels leading to fluid buildup in the lungs, bleeding, and failure of the heart to pump effectively. The combination of these changes can lead to low blood pressure, inadequate blood flow, failure of several organs and even death.
HPS is diagnosed based on clinical and laboratory evidence using blood tests and/or samples of fluid collected from the lungs.
There is no specific treatment for hantavirus infection. People with hantavirus infection and severe symptoms need in-hospital supportive care, including rest, hydration, and treatment of symptoms.
Only deer mice are considered a significant source of hantavirus in BC. However, since it is not easy to determine what kind of rodents may be in a home, it is best to remove all rodents and rodent-proof your home. Here are some ways to determine if a home or workplace is infested:
- Rodent droppings are one of the most reliable signs of a rodent problem. You may find droppings in cupboards, drawers or in bins, under the sink, along walls etc.
- Nests – you may find accumulations of materials that are soft and warm for rodents, like shredded paper, bits of insulation, furniture stuffing, etc.
- Food boxes, containers or food itself that appears to be nibbled
- Since rodents need to gnaw things constantly, to keep their teeth from growing too long, you may find signs of gnawing
- An ammonia-like odour may be a sign of an infestation
- Seeing rodents in the daytime is a possible sign of a heavy infestation
- For information on how to protect yourself at home or at your workplace, check out HealthlinkBC, speak to your local health unit or visit
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