Mosquitoes in St. Marys Test Positive for West Nile Virus

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Huron Perth Public Health (HPPH) reminds residents to protect themselves against mosquito bites following confirmation that mosquitoes collected from a trap in St. Marys tested positive for West Nile Virus (WNV). This is the first WNV positive mosquito finding of the season for Huron and Perth counties.

“It’s not surprising to see WNV positive mosquito pools in the month of August,” says Dale Lyttle, 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, especially when mosquitoes are most active.”

2023 Mosquito Surveillance and Control Activities

HPPH has been trapping and testing mosquitoes in locations across Huron and Perth since June 20. To reduce the risk of potential WNV transmission in Perth County, larvicide is being applied to roadside catch basins in Stratford, St. Marys, Listowel and Mitchell this summer to help reduce mosquito breeding.

West Nile Virus in Humans

In Ontario, no probable or confirmed human cases of WNV have 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 the chest, stomach or back. About one 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 containing DEET or Icaridin when outdoors. Be sure to follow the manufacturer’s directions.
  • Covering up with light-coloured 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.

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