Canada’s top doctor concerned about measles outbreaks in Ontario, Quebec

Chief Public Health Officer of Canada, Dr. Theresa Tam speaks at the Canadian Immunization Conference, in Ottawa, Wednesday, Nov. 27, 2024. THE CANADIAN PRESS/Adrian Wyld

Canada’s top doctor says she is concerned about measles outbreaks with a growing number of cases acquired locally and spreading in Ontario and Quebec.

Dr. Theresa Tam says the majority of recent infections reported in Canada were among people who were unvaccinated, including many children, and infants under one.

Tam says all of the people who were recently infected were exposed to measles in Canada, rather than international travel, which was the initial source.

Health Canada reported eight measles cases as of Jan. 11, but local public health units have released more recent numbers with much higher case counts.

Ontario public health reported 38 measles cases – 12 confirmed and 26 probable – as of Jan. 15 linked to an out-of-province travel exposure in New Brunswick. Grand Erie Public Health also reported a new measles case Wednesday in a child who is recovering at home.

As of Tuesday, health officials in Quebec reported 16 cases of the highly contagious infection.

Tam says measles can spread “very quickly” and warns 90 per cent of unvaccinated people or those who haven’t had a prior infection will get sick if they are near someone who has it.

Measles is airborne disease and in rare cases can lead to respiratory failure, swelling of the brain and death.

“I’m concerned that vaccination rates for measles among children are not high enough in some areas of Canada to prevent the spread of measles,” Tam said in a statement Wednesday.

A study published in the Canadian Journal of Public Health in October found a decline in measles vaccination coverage children ages two to seven before, during, and after the COVID-19 pandemic.

This report by The Canadian Press was first published Jan. 29, 2025.

Hannah Alberga, The Canadian Press