SIMCOE MUSKOKA – The Simcoe Muskoka District Health Unit (SMDHU) continues to see West Nile virus (WNv) activity in our communities with a positive test reported in a bird in the City of Barrie and a second mosquito pool testing positive for the virus in the Town of New Tecumseth. These positive results are in addition to the positive test in a bird in the municipality of Bradford West Gwillimbury during the month of July and a positive mosquito pool reported last week in New Tecumseth.

To date, no human cases of WNv have been reported in Simcoe Muskoka in 2025. However, the health unit is reminding the public that an increase in virus among birds and mosquitos presents a higher likelihood that the virus can spread to humans. West Nile virus circulates between birds and some species of mosquitoes. The virus can be transmitted to humans by a mosquito bite, if the mosquito has first bitten an infected bird.

The health unit continues its monitoring of mosquito populations by setting mosquito traps and looking for larvae in selected locations in Simcoe Muskoka throughout the summer. Where positive results have been obtained, additional surveillance measures are undertaken. Positive test results are a reminder that we all need to continue to take appropriate measures to protect ourselves against WNv at this time of year, and the best way to do this is by protecting yourself from mosquito bites.

The risk of contracting WNv from an infected mosquito is highest in late summer. The health unit recommends the following personal protection measures:

• Use an approved mosquito repellent and follow manufacturer’s instructions.
• Wear light-coloured clothing and cover up in areas where mosquitoes are present.
• Stay indoors when mosquitoes are most active – at dusk and dawn – when possible.

Although most people will not become sick if bitten by an infected mosquito, WNv can cause severe illness in some people. Symptoms of WNv include fever, muscle weakness, stiff neck, confusion, severe headache and a sudden sensitivity to light. In very rare cases, the virus may cause serious neurological illness. Anyone experiencing symptoms should seek medical advice.

Anyone with concerns about a dead bird can contact the Canadian Wildlife Health Cooperative (CWHC) at 1-866-673-4781.