Mosquitoes in Toronto have tested positive for West Nile Virus. Here’s what you need to know to protect yourself – CTV
July 22, 2025
West Nile is back in the headlines, with mosquitoes testing positive for the virus in Toronto, Niagara Region and York Region in the last week.
While there haven’t been any confirmed cases in humans in Ontario so far this year, there are a few crucial things to know about the virus and how to protect yourself from it.
What is the West Nile virus?
West Nile is a mosquito-borne virus that has the potential to cause fatal neurological disease. It is transmitted to humans through mosquitoes.
Mosquitoes initially catch West Nile by feeding on perching birds, like robins, that habour the virus, creating a cycle, explained Dr. Robyn Klein, a professor at Schulich Medicine & Dentistry whose focus is on neurovirology and neuroimmunology.
