West Nile Virus Returns to Canada: Prevention and Awareness

The West Nile virus has made its unwelcome return to Canada for another season. It has been detected in mosquitoes across various regions of Ontario, including Toronto, just in the past week. Despite there being no reported human cases of the virus in Canada as of the current week, health-care professionals are urging caution.

First Detection of West Nile Virus

The West Nile virus was first detected in Canada in August 2002 according to Infection Prevention and Control Canada (IPAC). The virus primarily infects birds and is spread to humans by mosquitoes that have fed on the blood of these infected birds. Human cases are typically seen in mid- to late summer and into early fall. About 70 to 80 per cent of the infected people may not even realize they have it, as they will show no symptoms.

Symptoms of West Nile Virus

For those who do show symptoms, they typically include fever, headache, body aches, a mild rash, and swollen lymph glands. These symptoms usually appear within two to 15 days after infection. The Public Health Agency of Canada (PHAC) reports that less than one per cent of people infected with the virus will develop severe symptoms and health effects. It can cause inflammation of the brain and spinal cord, and even a paralysis-type syndrome that’s reminiscent of polio.

Who is at Risk?

People 50 years and older, those with chronic diseases like cancer and heart disease, and those with weakened immune systems are at higher risk of severe symptoms. In severe cases, symptoms can include the rapid onset of a severe headache, high fever, stiff neck, nausea, vomiting, difficulty swallowing, drowsiness, confusion, and loss of consciousness. Muscle weakness or paralysis are also possible in severe cases.

Preventing the Spread of West Nile Virus

The risk of becoming infected with West Nile virus starts in mid-April and lasts typically until the first hard frost in either late September or October. To reduce the risk, people should cover exposed skin by wearing long pants and loose-fitting, long-sleeved shirts, socks, and a hat. Light-coloured clothing is recommended as mosquitoes are attracted to dark colours. Insect repellents containing DEET or icaridin can also help prevent bites. It’s also suggested to put screens on windows and doors to reduce mosquitoes near homes.

Enjoying the Summer Safely

Despite the presence of the West Nile virus, Canadians are encouraged to still enjoy the summer. Dr. Isaac Bogoch, an infectious diseases specialist, advises citizens to be aware of the virus but not to let it prevent them from enjoying outdoor activities. “No reason to hide indoors because of this. Just go outside, have a wonderful time”, he said.