Toronto Public Health reports first confirmed human case of West Nile virus in 2025

Toronto Public Health is reporting its first laboratory-confirmed human case of West Nile virus in an adult resident in 2025. West Nile virus is transmitted to people through the bite of an infected mosquito.

Residents can take the following precautions to avoid bites from mosquitoes:

• Wear light-coloured, long-sleeved shirts and long pants when outdoors.
• Apply insect repellent approved by Health Canada and follow the manufacturer’s instructions.
• Take extra care at dawn and dusk when mosquitos are most active by using insect repellent and covering exposed skin.
• Eliminate standing water on your property where mosquitoes can breed. This includes water that collects in items such as buckets, planters, pool covers, toys and waste containers.
• Ensure windows and doors have tight-fitting screens.

West Nile virus symptoms usually start to show between two and 14 days after a person is bitten by an infected mosquito. Symptoms can include:

• Fever
• Headache
• Nausea
• Vomiting
• Body aches
• Skin rash
• Swollen lymph glands
• Stiff neck

Older individuals or people with compromised immune systems are at higher risk of severe illness.

More information about West Nile virus and ways to reduce the risk of infection are available on the City’s webpage.

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