Mosquitos test positive for West Nile virus in Ajax


Published August 4, 2023 at 1:10 pm

west nile ajax
Photo by Jimmy Chan

Another batch of mosquitoes tested positive for West Nile virus in Durham — this time in Ajax.

The adult mosquitoes were collected from one of the Durham Region Health Department’s mosquito trap sites, the health department said in a press release today (Aug. 4).

This is now the fifth mosquito batch in Durham Region to test positive for the virus this season.

The first batch was found in Oshawa in July.

Durham Region Health Department sets mosquito traps across the region and submits mosquitoes for laboratory testing every week between June and September.

This positive test comes as the health department advised residents to watch for symptoms of the virus.

Most people who contract the virus will experience mild illness including fever, headache, body ache, nausea, vomiting, and rash on the chest, stomach or back.

More serious symptoms can include muscle weakness, stiff neck, confusion, tremors, numbness and sudden sensitivity to light.

Symptoms usually develop between two and 15 days after being bitten by an infected mosquito.

West Nile virus is a mosquito-borne disease that is spread to humans via the bite of an infected mosquito. Mosquitoes become infected by feeding on the blood of a bird that carries the virus. The disease is not passed from person to person, nor from bird to person.

Although the risk of becoming infected is low, the Health Department recommends that residents take the following precautions:

  • Wear shoes, socks, and light-coloured clothing—including long sleeve tops and full-length pants when outside—especially at dusk or dawn when mosquitoes are most active.
  • Use insect repellent containing DEET or Picaridin on exposed skin, following Health Canada’s safety tips on using personal insect repellents.
  • Remove standing water from your property where mosquitoes can breed.
  • Ensure window and door screens are in good repair to prevent mosquitoes from entering your home.

Durham Region helps minimize mosquito populations by treating Regional catch basins and other stagnant water sites with a larvicide to help reduce breeding.

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