Durham Region Health Department has confirmed that adult mosquitoes collected in Clarington have tested positive for West Nile virus (WNv). This marks the first positive mosquito batch for the virus in Durham Region for the 2025 season.
The mosquitoes were gathered from one of the Health Department’s monitoring traps in Clarington. From June through September, traps are set across the region and mosquito samples are sent for laboratory testing as part of ongoing surveillance efforts.
West Nile virus is transmitted to humans through the bite of an infected mosquito. Mosquitoes acquire the virus by feeding on birds carrying the disease. It cannot be transmitted from person to person or from birds directly to humans.
While the risk of infection remains low, the Health Department is reminding residents to take precautions. Most individuals who contract West Nile virus may experience mild symptoms such as fever, headache, body aches, nausea, vomiting, or a rash on the chest, stomach, or back. However, more serious symptoms can include muscle weakness, confusion, stiff neck, tremors, and sensitivity to light. These typically appear between two to 15 days after being bitten.
To reduce the risk of mosquito bites and possible infection, Durham Region Health Department recommends the following:
- Wear shoes, socks, and light-coloured clothing, including long sleeves and pants, especially during dawn and dusk when mosquitoes are most active.
- Use insect repellent containing DEET or Picaridin on exposed skin, following Health Canada guidelines.
- Eliminate standing water on your property where mosquitoes can breed.
- Ensure that window and door screens are in good condition to keep mosquitoes out.
The Region also treats catch basins and stagnant water sites with larvicide as part of its mosquito control strategy.
For more information on West Nile virus, residents can contact the Durham Health Connection Line at 905-668-2020 or 1-800-841-2729, or visit durham.ca/WestNile.