Public Health Sudbury & Districts reports human case of West Nile virus

Public Health Sudbury & Districts has received laboratory results confirming an adult in Greater Sudbury has tested positive for West Nile virus (WNv). Before this, the most recent laboratory confirmed cases within the Sudbury and Manitoulin districts were in 2017.

A mosquito that was positive for West Nile virus was detected in the Manitoulin District earlier this season through routine surveillance, and positive mosquitos and birds have been identified within the districts in previous years. Routine surveillance via trapping of mosquitos continues within the Public Health Sudbury & Districts’ service area.

“Although reports of West Nile virus in humans are uncommon, the threat posed by the virus remains as the virus is found across Ontario,” said Jonathan Groulx, a manager in Public Health’s Health Protection division. “Taking precautions to protect against the infection is important,” added Groulx.

West Nile virus is spread through the bite of an infected mosquito. Mosquitoes get the virus by feeding on infected birds. Symptoms can range from mild to severe. Most people infected with the virus have no symptoms while others may experience mild symptoms including fever, headache, body aches, mild rash, and swollen lymph glands. In very rare cases the infection can affect the central nervous system and cause serious symptoms.

Late summer is typically the time of greatest risk for contracting West Nile virus. Mosquitoes can carry higher levels of the virus at this time, and this is when people might not be as careful about protecting themselves from mosquito bites. Here are some simple measures you can take to continue to protect yourself and your family:

Reduce the risk around the home

  • Install or repair window and door screens.
  • Remove standing water from around your home where mosquitoes can breed.
  • Carry out regular yard and lawn maintenance: collect lawn cuttings, raked leaves or other decaying debris and recycle or mulch them so that organic matter does not end up in storm sewers as a food source for mosquito larvae.
  • Turn over compost frequently.

Personal precautions

  • If possible, stay indoors from dusk to dawn when mosquitoes are most active.
  • Use mosquito netting when sleeping outdoors or in an unscreened structure and to protect small babies when outdoors.
  • Wear light-coloured, long-sleeved shirts, long pants, shoes, and socks when outside, especially from dusk to dawn, when mosquitoes are most active.
  • Use an approved insect repellent and follow the manufacturer’s recommendations.

For more information about West Nile virus, please contact Public Health Sudbury & Districts at 705.522.9200, (toll-free at 1.866.522.9200) or visit

This item was last modified on September 8, 2023