Ontario Declares Measles Outbreak Over, Public Health Officials Say
Ontario has formally declared the measles outbreak that unfolded over the past year to be over, according to a weekly epidemiology report from Public Health Ontario. The decision aligns with national guidance that marks an outbreak as complete 46 days after the onset of a rash in the last affected individual.
The last reported case in the outbreak developed a rash on August 21, setting the official endpoint as the later days of August and the closing weeks of summer 2025. After nearly a year of transmission and intense public health action, the province now transitions from escalation to continued vigilance against the disease.
Scope of the Outbreak
Ontario’s outbreak, which began on October 18 of the previous year, involved 2,375 people across 26 public health units. The source of the outbreak traces back to a exposure linked to a measles case contracted in New Brunswick, underscoring how quickly measles can travel within Canada’s interconnected communities.
The surge prompted a comprehensive public health response, including vaccination campaigns, outreach to schools and childcare facilities, and public information efforts designed to prevent further spread and protect vulnerable populations.
Impact and Consequences
While the majority of cases recovered, the outbreak had serious consequences. A baby in southwestern Ontario died after the mother contracted measles and delivered prematurely, highlighting the risk measles poses to newborns and pregnant individuals. Separately, another infant died in Alberta amid its ongoing measles outbreak, illustrating that the disease remained a concern in multiple provinces even as Ontario’s outbreak reached its end.
Current Situation and Public Health Guidance
Even with the outbreak declared over, health officials stress that measles continues to circulate in Canada. Ongoing surveillance and vaccination remain critical tools to prevent a resurgence, with public health units maintaining readiness to respond to any new cases or clusters that might surface.
Public Health Ontario notes that the end of the outbreak is supported by national criteria and is not a sign that measles has disappeared from the population. Citizens are encouraged to stay up to date with measles-containing vaccines, especially those in high-risk groups such as young children, pregnant individuals, and people with compromised immune systems.
What This Means for Ontario Residents
For residents, the declaration means a shift from emergency response to ongoing prevention and routine vaccination efforts. Schools and workplaces may experience a normalization of activities that were disrupted during the outbreak, but health officials remind everyone that vaccination remains the best defense against future measles spread.
Officials also emphasize the importance of seeking medical attention if measles symptoms appear, including fever, cough, runny nose, and a distinctive rash. Because measles is highly contagious, early identification and isolation of suspected cases help protect vulnerable populations and curb further transmission.
Looking Ahead
As Canada continues to monitor measles activity, provinces will likely maintain vaccination campaigns and public education to sustain herd immunity. The Ontario case demonstrates how a coordinated public health response can contain and eventually end a large-scale outbreak, even as measles remains a national health concern.
This report by The Canadian Press was first published Oct. 9, 2025. Public health officials will continue to track measles indicators and release updates as needed, ensuring the public remains informed about any new developments.
