Toronto Records First Human Case of 2026: How Residents Can Protect Against West Nile Virus

Toronto Public Health is urging residents to strengthen precautions against mosquito bites after the city recorded its first human case of West Nile virus in 2026.

The infection was reported in an adult Toronto resident on July 30. Earlier, on July 17, health officials confirmed that one batch of mosquitoes collected in the city had tested positive for the virus, marking Toronto’s first positive mosquito sample of the year.

West Nile virus is transmitted to people through the bite of an infected mosquito. Although public health officials say the overall risk of infection in Toronto remains low, residents are advised to take precautions throughout the summer, particularly around dawn and dusk when mosquitoes are most active.

Toronto Public Health recommends wearing light-coloured, long-sleeved shirts and long pants while outdoors. Residents should also use an insect repellent approved by Health Canada and carefully follow the manufacturer’s directions.

Window and door screens should fit tightly and be repaired if they contain holes. Residents are also encouraged to regularly remove standing water from their properties because mosquitoes can lay eggs and reproduce in even small amounts of stagnant water.

Water should be emptied from pool covers, buckets, flowerpots, children’s toys, discarded tires, birdbaths and garden equipment. Gutters and drains should be cleaned, while leaking outdoor taps and hoses should be repaired to prevent water from collecting around homes.

Most people infected with West Nile virus do not become ill. The Public Health Agency of Canada says approximately 70 to 80 per cent of infected people experience no symptoms.

Those who do develop symptoms may experience fever, headache, body aches, a mild skin rash or swollen lymph glands. Symptoms generally begin between two days and approximately two weeks after an infected mosquito bite.

More serious warning signs can include the sudden onset of a severe headache, high fever, stiff neck, confusion, drowsiness, muscle weakness, loss of coordination, difficulty swallowing or loss of consciousness.

Medical attention should be sought immediately if severe symptoms develop. Adults aged 50 and older, people with underlying medical conditions and individuals with weakened immune systems face a greater risk of serious illness.

There is currently no specific vaccine or treatment for West Nile virus infection in humans. Medical care focuses on relieving symptoms and providing supportive treatment, while severe cases may require hospitalization.

Toronto conducts mosquito surveillance from mid-June until mid-September. Twenty-two mosquito traps are placed across the city each week, and collected mosquitoes are sent to a laboratory for identification and West Nile virus testing.