Ontario ends measles outbreak after 2,375 cases, 1 death, with most victims unvaccinated.

Ontario has declared its measles outbreak over after 46 days with no new cases following the last rash onset on August 21, 2024, meeting national criteria. The outbreak, linked to a travel-related case in New Brunswick, caused 2,375 infections in Ontario—2,060 confirmed and 315 probable—with 43 additional non-outbreak cases in 2025. Most cases occurred in unvaccinated children and adolescents, and 96.4% of those under 20 were unvaccinated; among adults, 69.9% were also unimmunized. There were 165 hospitalizations, 122 of them in children, 12 ICU admissions, and one infant death. Public health officials stress ongoing vigilance, as measles remains circulating in Canada and globally, and emphasize the importance of vaccination to prevent future outbreaks.