Crow from Grey-Bruce tests positive for West Nile Virus

West Nile Virus risks

West  Nile Virus (VWN) has been found in a crow in Grey Bruce County.

Grey Bruce Public Health was notified that an American crow from Grey-Bruce tested positive for the mosquito-borne disease.

The crow, known carriers of WNV, was submitted to the Canadian Wildlife Health Co-operative for testing earlier this month.

The health unit says the risk to humans remains low, yet finding a diseased bird serves as a reminder of the importance of taking steps to prevent mosquito bites.

“People are most at risk of becoming infected with West Nile Virus in late summer,” said senior public health manager Andrew Barton.

“The single most effective way to prevent the virus is to prevent mosquito bites, such as by using insect repellent containing DEET or Incaridin and covering exposed skin outdoors, particularly at dusk and dawn when mosquitoes are most active,” Barton said.

This is the first bird to test positive for WNV in Grey-Bruce in 2024.

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As of August 17, six Ontario residents have tested positive for WNV, according to Public Health Ontario. No human cases of the virus have been reported in Grey-Bruce.

WNV circulates between birds and mosquitoes. The virus can be transmitted to humans by a mosquito bite if the mosquito has first bitten an infected bird.

The health unit sets mosquito traps from May to September in each Grey-Bruce municipality as part of its West Nile surveillance program. The traps are sent to a laboratory for species identification and viral testing.

So far this year, no positive mosquito pools have been identified in Grey-Bruce. Public Health has set up additional traps where the dead crow was located.

Ways to prevent mosquito bites and prevent WNV include:

• Wearing light-coloured long pants and long sleeves, socks, and a hat when outdoors;
• Reducing mosquito habitats near the home by eliminating standing water in flowerpots, eavestroughs, etc.;
• Taking extra protection measures between dusk and dawn when mosquitoes are most active and
• Ensuring door and window screens fit securely and are free of holes.

Most people infected with WNV do not experience any symptoms. Other people may see symptoms two to 15 days after being bitten by an infected mosquito. Symptoms are usually mild, including a fever and headache; however, serious symptoms can occur.

Some people are at greater risk for serious health effects from the virus. These include anyone:

• over the age of 50;
• with chronic diseases, such as cancer, diabetes, alcoholism, and heart disease;
• who require medical treatment that may weaken their immune system, such as chemotherapy.

Anyone with concerns about a dead bird can contact the Canadian Wildlife Health co-operative at 1-866-673-4781.