Ontario measles outbreak linked to New Brunswick gathering

An outbreak of measles in Ontario is linked to a large gathering in a Mennonite community in New Brunswick last fall. Dr. Kieran Moore, Ontario's chief medical officer, noted that most cases are among unvaccinated individuals. As of February 26, there have been 177 reported cases in Ontario. The majority are in the Grand Erie and Southwestern Public Health regions. The outbreak is affecting some Mennonite, Amish, and other Anabaptist communities due to low vaccination rates and exposure to measles. In addition to Ontario, cases have also appeared in Manitoba from family visits. Moore warned that more cases may arise after travel during March break. He advised health-care providers to consider measles in patients with respiratory symptoms, especially those who have traveled to high-risk areas. New Brunswick declared its measles outbreak on November 1, 2024. Health officials there managed to vaccinate 239 people at various clinics. This outbreak resulted in a total of 50 cases, which was declared over on January 7. Nationwide, 369 measles cases have been reported in Canada since January 2025. Measles is preventable with vaccination. The measles-mumps-rubella (MMR) vaccine is available in Canada and is highly effective, especially with two doses.