End of the measles outbreak in Quebec
Posted August 3, 2026 12:48 pm.
The most recent measles outbreak in Quebec, the first cases of which were reported at the beginning of the summer, is officially over. A total of 28 cases were identified, suggesting that the spread of the virus was limited.
For each case of measles reported in Quebec, a public health investigation is conducted to determine the origin of the infection in order to identify people at risk of having been exposed to the virus and contact them to monitor their symptoms.
To combat measles, public health officials remind the population that the best way to protect themselves against this highly contagious virus is to get vaccinated.
According to the criteria of the Ministry of Health, for the end of a measles outbreak to be declared, 32 days must have passed after the presence of the last contagious case in a setting in Quebec.
Since the last case of measles in Quebec dates back to July 1st, the 32 days have passed.
The duration of the end of the outbreak is determined on the basis of two average incubation periods of the disease (two times 14 days) plus the maximum transmissibility period of four days after the appearance of the rash.
This is the fourth outbreak in Quebec since 2024. A total of 130 cases have been reported across these four outbreaks, according to the Government of Canada’s measles surveillance report. This data includes some measles cases reported in Quebec involving individuals who do not reside in Canada.
The first outbreak in Quebec, which began in February 2024, lasted approximately four months and 51 cases were confirmed, making Quebec the epicenter of measles transmission across the country. There were 77 cases of measles in all of Canada at that time.
Since then, the situation has changed. By 2025, Ontario and Alberta were by far the provinces most affected by the spread of measles, each exceeding 2000 cases within their territory.
As of July 18, 2026, 1107 cases of measles have been reported in Canada.
On the American side, the situation has worsened, with the country facing its worst outbreak in 35 years. As of July 30, according to the Centers for Disease Control and Prevention, 2,371 cases had been recorded in the United States.
—The Canadian Press’s health coverage is supported by a partnership with the Canadian Medical Association. The Canadian Press is solely responsible for this journalistic content.
–This report by La Presse Canadienne was translated by CityNews
