The most recent measles outbreak in Quebec, the first cases of which were reported at the start of the summer, is officially over. A total of 28 cases were recorded, suggesting that the spread of the virus was limited. For every case of measles reported in Quebec, a public health investigation is carried out to determine the source of the infection, so that people at risk of having been exposed to the virus can be identified and contacted to monitor their symptoms. To combat measles, public health authorities remind the public that the best way to protect themselves against this highly contagious virus is to get vaccinated. According to the Ministry of Health’s criteria, for a measles outbreak to be declared over, 32 days must have elapsed since the last infectious case was identified in a setting in Quebec. As the last case of measles in Quebec was on July 1, the 32 days have now elapsed. The duration until the end of the outbreak is determined on the basis of two average incubation periods for the disease (twice 14 days) plus the maximum period of transmissibility of four days after the onset of the rash. This is the fourth outbreak in Quebec since 2024. In total, 130 cases were reported for these four outbreaks, according to the Government of Canada’s measles surveillance report. These figures include some measles cases reported in Quebec involving a person who does not reside in Canada. The first outbreak in Quebec, which began in February 2024, lasted around four months and saw 51 confirmed cases, making Quebec the epicentre of measles transmission across the country. There were 77 cases of measles across Canada at that time. Since then, the situation has changed. In 2025, Ontario and Alberta were by far the provinces most affected by the spread of measles, with each recording over 2,000 cases within their borders. As of July 18, 2026, 1,107 cases of measles had been reported in Canada. In the United States, the situation has worsened, with the country facing its worst outbreak in 35 years. As of July 30, according to the Centres for Disease Control and Prevention, 2,371 cases had been recorded in the United States. This report by The Canadian Press was first published in French on Aug. 3, 2026. 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.
