What to know about rising cases of measles in Canada
Measles, though having been officially eliminated in Canada, is one of the world’s most contagious diseases, and as outbreaks of the preventable virus continue to occur in Europe and the U.S., and cases pop up throughout Canada, it could be a sign vaccination rates have fallen below what is necessary to keep the disease at bay.
“If one person who’s infected is exposed to 10 people who are not infected, probably nine of those 10 people will get the infection, (assuming they are not vaccinated),” said Jacqueline Khet-ling Wong, staff physician and assistant professor in the Department of Pediatrics, Division of Infectious Diseases, at Mcmaster University. “The groups where we normally see complications would be children, pregnant women and the immunocompromised, but, worldwide, in terms of the number of infections, hospitalizations, complications and even deaths ... is borne by children.”
On Friday, according to Montreal health officials, a case of measles in Laval shows signs that it may be active in the community, as an unvaccinated person contracted the virus without leaving the country and without interacting with another known host.
This comes at the beginning of March break in Quebec and New Brunswick and, at most, a few weeks before it happens in other provinces. March break and international travel as a whole, according to Chief Public Health Officer Theresa Tam, could be a significant catalyst in the spread of measles in unprotected pockets of the Canadian population. Tam urged those who are currently not fully vaccinated against the virus to get their two doses, especially before any international travel.
“You’re just a flight away sometimes in terms of exposure to infections in other parts of the world,” Wong said. “Before you travel, it’s always a good opportunity to talk to either your primary care provider or to go to a travel clinic to see if there’s anything you can do ... so that you enjoy your travel and stay healthy while you’re there and when you return.”
As of Feb. 23, health officials were aware of six cases of measles in Canada since the beginning of the year, but with the string of recent cases in Montreal, that number has certainly risen. In 2023, there was a total of 12 known cases of measles throughout the entire year.
The first known case of measles this year was an infant in Toronto, who is believed to have contracted the virus after international travel. However, another case in York Region, Ont., saw a fully vaccinated 30-year-old man become infected with a mild form of the disease.
Unlike the three other cases of measles in Ontario before that point, he had contracted the virus without travelling or interacting with anyone known to be carrying the virus.
Since COVID-19, surveys have shown that Canada has a small minority of people who are increasingly vaccine hesitant or against vaccination for their children. According to data from Statistics Canada, the percentage of two-yearolds who have one dose of the vaccine has increased from 89.2 per cent in 2015 to 91.6 per cent in 2021. However, the percentage of seven-yearolds who have two doses of the vaccine has decreased from 87 per cent in 2017 to 79.2 per cent in 2021. While no vaccine offers guaranteed protection, those with two doses of the measles vaccine are less likely to get infected than those with one dose or none.