West Nile Virus Activity Reported in Huron Perth

Huron Perth, ON - Huron Perth Public Health (HPPH) reminds residents to protect themselves against mosquito bites following confirmation that mosquitoes collected from traps in Listowel and Mitchell have tested positive for West Nile Virus (WNV). These are the first positive mosquito 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.”

Mosquito Surveillance and Control Activities

As part of annual mosquito surveillance, HPPH has been trapping and testing mosquitoes in locations across Huron and Perth since June 16, 2025. To reduce the risk of potential WNV transmission, larvicide is applied to roadside catch basins in Stratford, St. Marys, Listowel and Mitchell over the summer to help reduce mosquito breeding.

West Nile Virus in Humans

In Ontario, one confirmed human case of WNV has been reported. Not everyone who is bitten by an infected mosquito will show symptoms of the virus. Of those who do show symptoms, most will experience mild illness, including fever, headache, body aches, nausea, vomiting and rash on chest, stomach or back. About 1 in 150 people infected will get seriously ill, with symptoms like high fever, muscle weakness, vision loss and coma. WNV can lead to death.

Symptoms usually develop between two and 15 days after being bitten by an infected mosquito. People older than 50 are most at risk for WNV infection as are those with weakened immune systems.

Protect Yourself from Mosquito Bites

People can protect themselves from mosquito bites by:

• Using an insect repellent when outdoors containing DEET or Icaridin. Be sure to follow the manufacturer’s directions.
• Covering up with light-colored clothes, long sleeves and pants when outdoors or in areas where mosquito activity is high.
• Taking extra protection measures at dusk and dawn when mosquitoes are most active.
• Removing standing water around the home at least once a week to reduce mosquito breeding grounds.