Measles is making a comeback in Canada. What’s driving the surge?

Measles is making a troubling comeback in Canada this year, with cases rising sharply after years of near-elimination. What's going on?

Measles is making a troubling comeback in Canada this year, with cases rising sharply after years of near-elimination.

So far this year, Canada has reported 95 cases of measles (as of Feb. 21), with British Columbia, Manitoba, Ontario and Quebec bearing the brunt of the outbreak, the latest data from the Public Health Agency of Canada (PHAC) shows.

At this time last year, there were only four reported measles cases.

By the end of 2024, Canada had recorded a total of 146 cases.

“If you look at Ontario in the 2025 calendar year, it’s only February. And we already have roughly the same amount of cases of measles in February of 2025 as we did all of 2024. So no, we are not headed in the right direction,” said Dr. Isaac Bogoch, an infectious diseases specialist at Toronto General Hospital.

Measles is one of the most contagious infectious diseases — more contagious than diseases like COVID-19, influenza and chickenpox. This high level of contagiousness is one reason why measles outbreaks can spread rapidly, particularly in areas with low vaccination rates.

“It’s so transmissible; if someone was in a room that had the measles and then they left the room, and an hour or two later, another person entered that room who is not immune to measles, there’s a high probability that they would get infected with measles,” Bogoch said.

“It has a knack for finding unvaccinated or under-vaccinated people and under-vaccinated communities.”