Quebec’s ministry of health says it's on the verge of declaring its measles outbreak over, just as cases reach new heights in other parts of the country.
The province says it has not recorded a new measles case since it hit 40 infections on March 18.
If no additional cases are reported by Saturday – 32 days after the last contagious case – the ministry says it will signal the end of the outbreak.
That’s a stark contrast to Ontario, where measles cases have exceeded 800 since an outbreak began in the fall, and Alberta, which on Wednesday recorded 84 cases since March.
Quebec’s outbreak began in December 2024 with a traveller who was visiting the province while contagious with measles, before they were diagnosed.
Most of the province’s cases – 32 out of the 40 – were reported in Laurentides, about a two-hour drive north of Montreal.
Laurentians’ public health director Dr. Éric Goyer says measles entered the region after an infectious person at a conference in Montreal came into contact with a local, who then spread it to unvaccinated family members.
Measles has stayed relatively contained within the Laurentides because people work, shop and go to school within the region, he says.
But in 2011, Quebec faced its own sprawling spread of measles with more than 700 cases — at the time, it was the largest measles outbreak in a decade.
Since then, Quebec has established an electronic vaccination register, which Goyer says has been an important tool in dealing with this latest outbreak.
Ontario doesn’t have an electronic vaccine registry, which has been a point of contention in the province, with the province’s immunization advisory committee strongly urging the ministry of health to move to a digital system.
Quebec also has a stay-at-home policy for unvaccinated students and staff if there is at least one measles case at a school, which was enforced for 130 unvaccinated people in the region, lasting about four to seven days in each case.
"These are tools that we didn't have a few years ago and that now, in the current measles outbreak, are very, very helpful."
Quebec's measles vaccination coverage among secondary school students was about 91 per cent in the 2023 to 2024 school year, and just over 90 per cent in the current school year, which was measured up until the end of January.
In Ontario, 92 per cent of 17-year-olds were vaccinated against measles in the 2023 to 2024 school year, according to the latest public health data.
Because measles is one of the most contagious diseases in the world, 95 per cent vaccine coverage is needed to prevent outbreaks. Secondary school students in Laurentides have about 90 per cent coverage in the current school year.
In 2023, the public health unit contacted 6,000 parents of unvaccinated elementary school students based on the vaccination registry, and made 500 appointments for measles shots.
Vaccination initiatives during this latest outbreak helped boost coverage for nine and 10-year-olds from 90 to 92 per cent between December 2024 and April 2025.
“Every point that we can gain in terms of vaccination coverage helps us a lot,” Goyer says.
Dr. Nicholas Brousseau, a physician at Quebec’s national institute of public health, says the key difference is that the current measles outbreak didn't enter a highly unvaccinated community as it did in Ontario. If it had, it could have had a similar outcome.
“There may be small differences in vaccination coverage ... but in the end, I think this could have happened in Quebec or in other provinces,” says Brousseau.
Ontario’s top doctor has said the “vast majority” of Ontario’s measles cases are in Mennonite, Amish and other Anabaptist communities in the Southwestern public health unit due to under-immunization and exposure.
But the local medical officer of health has cautioned against associating the spread of the illness with a single demographic, and emphasized that being part of any particular group or religion doesn't put you at risk, but being unvaccinated does.
Goyer notes that there is no evidence the Quebec outbreak is rooted in any specific community.
Given the fact that the Laurentides is a rural area, Dr. Donald Vinh says health-care infrastructure is less accessible, compared to an urban centre like Montreal.
“It's clearly not the same as in urban areas. That's just a general phenomenon. And that could be one component,” Vinh says.
In Montreal, Dr. Earl Rubin says there have been no cases during this recent outbreak at Montreal Children's Hospital where he is the chair of the division of pediatric infectious disease.
"We thankfully were spared for now. And I mean, I don't want to talk too soon. You never know."
- With files from Maura Forrest
This report by The Canadian Press was first published April 16, 2025.
Canadian Press health coverage receives support through a partnership with the Canadian Medical Association. CP is solely responsible for this content.
Hannah Alberga, The Canadian Press
