Canada loses measles elimination status after year-long outbreak

Canada has lost its measles elimination status following a year-long outbreak that has affected nearly every province and territory, according to health officials.

The Public Health Agency of Canada (PHAC) said the Pan American Health Organization (PAHO) formally notified the government on Monday that the country no longer meets the criteria for measles elimination.

The decision follows confirmation that the same strain of the virus has circulated in Canada for more than 12 months, primarily within under-vaccinated communities. While transmission has slowed, it remains active in several provinces.

The ongoing outbreak began in October 2024 and has involved thousands of confirmed cases across Alberta, British Columbia, Manitoba, New Brunswick, Nova Scotia, Ontario, Prince Edward Island, Quebec, Saskatchewan, and the Northwest Territories.

PHAC said it is working with PAHO, as well as federal, provincial, and territorial partners, to improve vaccination coverage, strengthen data sharing, and enhance surveillance efforts.

PAHO also announced that the Region of the Americas has lost its verification as free from endemic measles transmission after determining that endemic circulation had been reestablished in Canada.

“As a result, the Americas, which was the first region in the world to eliminate measles twice, has now lost its measles-free status,” PAHO said in a statement.

“This loss represents a setback—but it is also reversible,” said PAHO Director Dr. Jarbas Barbosa. “Until measles is eliminated worldwide, our Region will continue to face the risk of reintroduction and spread of the virus among unvaccinated or under-vaccinated populations.”

As of November 7, PAHO reported 12,596 confirmed measles cases across ten countries in the Americas, a 30-fold increase compared to 2024. Most infections occurred in Canada, Mexico, and the United States, with 28 deaths reported regionwide, including two in Canada.

Canada can regain its measles elimination status once transmission of the current virus strain is interrupted for at least 12 consecutive months.