Canada is at risk of losing its measles elimination status as an outbreak that started in New Brunswick last year continues to grow.

Measles has been considered eliminated in Canada since 1998, and the country saw an average of 91 cases annually before October 2024, when the outbreak began. The designation means that, within a certain geographical region, there has been no sustained measles transmission over 12 consecutive months.

Since then, of the 4,394 measles infections nationwide, Health Canada data shows that most individuals were exposed to the virus domestically (94 per cent) and were not vaccinated (88 per cent).

So far, measles cases have been reported in every province and territory except Nunavut, Yukon, and Newfoundland and Labrador. According to most recent figures, Ontario has reported 2,353 cases as of July 29 and Alberta has reported 1,691 as of Aug. 5. One death was reported in Ontario in an infant who was born prematurely and had a congenital case of measles, as well as other underlying medical conditions.