Parents, educators on alert as Ontario measles outbreak rises to 572 cases

TORONTO — A mother of an infant, a principal of a religious school, and a public health physician — they all share the desire to get kids vaccinated against measles as Ontario recorded another 102 cases over the past week.

Public Health Ontario said Thursday there have been 572 cases since the outbreak began in October, 453 of them confirmed and 119 probable. Of the 42 people requiring hospitalization, two have required intensive care, and 36 have been children — most of them unvaccinated.

The highly infectious disease is still predominantly impacting unvaccinated infants, kids and teenagers, most in Southwestern and Grand Erie public health units.

That worries Rosemary Tamburini, whose nine-month-old baby is just a few months shy of his first measles shot.

She doesn’t want to wait to vaccinate her child any longer, and is considering early immunization.

“I don’t think I’m alone in that. I’ve had discussions with several moms in Ontario who are in a similar situation looking to potentially get vaccinated early,” said Tamburini, who lives in Toronto’s west-end suburb, Etobicoke.

The measles vaccine typically starts for babies at one-year-old, but Ontario public health units have made it available to babies as young as six months in response to the outbreak.

New measles cases have appeared in Waterloo, in the western edge of the Greater Toronto Area, and Lambton County in southwestern Ontario. Just south in Chatham-Kent, cases nearly doubled to 39 in the past week, and the spread continues northeast in Huron Perth where 55 people have been sickened.

Almost all of the cases are tied to a multi–jurisdictional outbreak that began with a travel-related case in New Brunswick and spread to Ontario and Manitoba. Ontario’s medical officer of health sent a memo to local public health units earlier this month stating the origin of the outbreak was a large gathering with guests from Mennonite communities in New Brunswick last fall.

Dr. Kieran Moore said cases are “disproportionately affecting some Mennonite, Amish, and other Anabaptist communities due to a combination of under-immunization and exposure to measles in certain areas.”

Not long after Christmas, a student at Walsingham Christian School, a private school in Norfolk County, part of the Old Colony Mennonite church, got measles.

Principal Martin Klassen said they called an impromptu meeting with parents to discuss vaccination and distributed information in Low German to a few parents not fluent in English. Most kids at the school are vaccinated, Klassen said. And for parents whose kids were not, “They were open to it,” he said.

In total, four kids tested positive for measles at the school around late January and early February, and all are back to school.

“Families deciding to get their children vaccinated or deciding to not get their children vaccinated has actually nothing to do with the baptism view that we have of religion. Absolutely nothing. Our ministers, our church, our brotherhood, we wouldn’t be spreading a view on should you or should you not get vaccinated,” Klassen said.

Further northeast in the province, Kelly Moorcroft teaches music at schools in Ottawa. Her first reaction to the outbreak in Ontario was anger and frustration.

“When I see something like measles making a comeback when it had been declared eradicated, it’s so discouraging,” Moorcroft said.

So far, Ottawa has not reported measles cases, but she’s watching closely, and preparing.

“If I were to have a student come into my studio and flat out say, ‘I’m not getting vaccinated,’ I’m not sure what I would do with that student. I would probably fire them from my studio,” she said.

But Moorcroft also acknowledged that many people in Ontario don’t have a family doctor to keep them on schedule with vaccinations.

“I’m lucky I have a doctor. There’s a lot of people out there that don’t have those.”

Huron Perth has set up vaccination clinics particularly for people without primary care providers.

Dr. Miriam Klassen, the public health unit’s medical officer of health, says health providers are also available to talk through safety concerns people may have about vaccine side effects and share information to mitigate fears.

“I actually would say we’re successful because people who are accessing vaccines haven’t been getting ill…. Most people are getting vaccinated and they aren’t getting impacted,” Klassen said.

Outbreaks are also being monitored in other provinces, though the case counts are smaller — including in British Columbia, Manitoba and Alberta where 18 people are diagnosed, most of them minors. Last week, Saskatchewan confirmed its second case and said it was investigating a third. The latest numbers in Quebec are unchanged at 40 cases since last week.

Measles is one of the most contagious diseases in the world. The World Health Organization says the virus can remain active in the air or on infected surfaces for up to two hours.

It usually begins with a fever, cough, runny nose and red watery eyes, followed by a red blotchy rash that starts on the face and spreads to the body and limbs. The virus can lead to pneumonia, inflammation of the brain and death.

The number of cases reported in Ontario over the last week is more than the number of cases recorded over the course of a decade between 2013 and 2023.

Throughout that entire time, Dr. Sarah Wilson has been with Public Health Ontario.

“I have to say that I had always hoped that we wouldn’t have this experience of supporting such a large measles outbreak,” Wilson said.

She’s part of a team that puts together the now-weekly reports on measles cases in the province, and when she looks at the numbers, she thinks about the people they represent.

“Especially when we look at those hospitalizations…there is personal stories behind the numbers.”

In the United States, there have been 378 confirmed cases recorded across 18 jurisdictions this year, according to Centers for Disease Control and Prevention (CDC) data from last week.

This report by The Canadian Press was first published March 27, 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