Health Department reports more West Nile virus positive mosquitoes

Whitby, Ontario – Durham Region Health Department has received notification of more adult mosquitoes that have tested positive for West Nile virus (WNV), with positive mosquitoes now reported at an additional mosquito trap site in Oshawa. This latest confirmation was received on Aug. 20. The first positive mosquitoes were reported from a trap located in north Oshawa on July 28. 

“This latest confirmation from additional traps in Oshawa now brings us to a total of four trap sites in Durham Region that have had mosquitoes test positive for West Nile virus so far this season,” said Laura Freeland, Manager, Health Protection with Durham Region Health Department. In addition to the two Oshawa locations, positive mosquitoes were also confirmed at two Pickering trap sites on Aug. 13. 

“As positive mosquitoes have been identified in Oshawa and Pickering, this is now evidence that West Nile virus is circulating in various areas of the community,” Ms. Freeland further explained. “Therefore, it’s important for residents in all Durham Region communities to take precautions against West Nile virus, including avoiding mosquito bites and removing standing water from their properties where mosquitoes are able to breed.” 

WNV 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 or from bird to person. 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. 

Although the risk of becoming infected is low, residents should still take the following precautions to minimize the risk of mosquito bites and the possibility of being infected with WNV:

• 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 that window and door screens are in good repair to prevent mosquitoes from entering your home. 

Durham Region Health Department sets mosquito traps across the Region and submits mosquitoes for laboratory testing every week between June and September. In addition, Regional catch basins and other stagnant water sites are treated with a larvicide to reduce mosquito breeding. For more information on WNV, please call Durham Health Connection Line at 905-668-2020 or 1-800-841-2729, or visit durham.ca/westnile.

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For more information, please contact the Health Department.