Huron Perth Public Health (HPPH) is reminding residents to protect themselves from mosquito bites after positive tests for West Nile Virus (WNV) in mosquito samples from Listowel and Mitchell. These are the first positive findings of the season for Huron and Perth counties.
“It’s not surprising to see positive mosquito pools in the month of August,” says Dale Lyttle, Senior Public Health Inspector. “In the late summer months, people are at greatest risk of contracting West Nile Virus, so it is important to protect yourself while outdoors when mosquitoes are most active.”
Since June 16, 2025, HPPH has been trapping and testing mosquitoes across the region. To help reduce mosquito breeding and the risk of WNV transmission, larvicide is applied to roadside catch basins in Stratford, St. Marys, Listowel, and Mitchell throughout the summer.
In Ontario, one confirmed human case of West Nile Virus has been reported this year. Not everyone bitten by an infected mosquito will show symptoms, but mild illness, including fever, headache, body aches, nausea, vomiting, and rash, is possible. About 1 in 150 infected people may become seriously ill, with symptoms such as high fever, muscle weakness, vision loss, and coma. The virus can be fatal.
People over the age of 50 and those with weakened immune systems are most at risk. Symptoms usually develop between two and 15 days after being bitten.
HPPH advises residents to protect themselves by using insect repellent containing DEET or Icaridin, covering up with light-coloured clothing, taking extra precautions at dawn and dusk, and removing standing water around the home at least once a week to reduce breeding grounds.