Durham Region reports first human cases of West Nile virus illness this year

Whitby, Ontario - Durham Region Health Department has received confirmation of two human cases of West Nile virus (WNV) illness, the first human cases in the Region this year. Also, Public Health Ontario is reporting an additional probable human case for the Region with confirmation pending. To date, 24 human cases have been reported in Ontario, while 166 WNV positive groups of mosquitoes have been identified across the province.

“While the overall risk of becoming infected with WNV is low, it’s important for everyone to take precautions to avoid mosquito bites,” explained Laura Freeland, Manager, Health Protection, with the Health Department. “Even though we’re now experiencing cooler weather, mosquitoes could still be active, and precautions are still advised.”

WNV illness is a mosquito-borne disease that is spread to humans through 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 three and 15 days after a bite from an infected mosquito.

Area residents are encouraged to help reduce the risk of WNV by removing stagnant water around their properties, including:

• removing unused objects that could collect water, such as tires, flowerpots, toys, etc.;
• turning over items such as wading pools, recycling boxes, wheelbarrows, and boats/canoes when not in use; and
• changing the water in bird baths and wading pools weekly and aerating ornamental ponds.

To minimize the risk of mosquito bites and the possibility of WNV infection, the Health Department recommends taking the following precautions:

• Wear shoes, socks and light-coloured clothing, including long sleeve tops and full-length pants, when outside especially during evening, nighttime or dawn when mosquitoes are most active.
• Ensure that window and door screens are in good repair to prevent mosquitoes from entering your home.
• Use an insect repellent containing DEET or Picaridin on exposed skin, following Health Canada’s safety tips on using personal insect repellents. Health Canada has more information on using insect repellents containing DEET at www.canada.ca/en/health-canada/services/about-pesticides/insect-repellents.html.

As part of its WNV surveillance program, the Health Department placed several mosquito traps throughout Durham Region. Mosquitoes caught in these traps were collected and tested weekly for the virus and a total of 10 groups of mosquitoes tested positive for WNV. The Health Department’s adult mosquito surveillance has now concluded for the 2020 season. For more information on WNV, please call Durham Health Connection Line at 905-668-2020 or 1-800-841-2729. Information is also available at durham.ca/westnile.

- 30 -

For more information, please contact the Health Department