The medical officer of health for Grey and Bruce counties says strong local vaccination rates and natural immunity are key factors helping to keep the measles outbreak under control in the region.
Dr. Ian Arra delivered an update to Grey County council on Thursday, appearing by video to share highlights from a March board of health meeting. His remarks come as health officials continue to monitor a multi-jurisdictional measles outbreak that began in October 2024.
Arra told council a majority of the public has immunity through vaccine or exposure.
"Anybody who's over 17, the immunization rate is above a provincial average, and it's in the 95 per cent range or around that number," Arra pointed out. "Under that, there is around 85 per cent with those numbers. I'm not losing sleep over major outbreaks or uncontrolled transmission."
However, Arra urged everyone to remain vigilant.
"We always recommend to stay home when sick," he added. "But during this time, many of these cases, you know, they manifest as just a common cold or some other symptom. But it's all over except for the shouting when the transmission already happened, because the person has been out and about."
The Grey Bruce Health Unit continues to advise the public to monitor for measles symptoms, which typically appear seven to 21 days after exposure, including high fever, cough, runny nose, sore eyes, and sensitivity to light. A rash of red spots and blotchy patches usually develops three to seven days after other symptoms, beginning on the face before spreading to the rest of the body.
Anyone experiencing symptoms is urged to immediately isolate at home and contact a health-care provider. Household members who are not immune should also remain home and seek guidance from Public Health.
Meanwhile, local health staff remain busy conducting contact tracing, a detailed and time-consuming process. He stressed tracing those potentially exposed is a crucial part of controlling the spread.
As the outbreak continues, public health officials are reminding residents of the critical importance of vaccination in protecting both individual and community health.
Ontario Public Health revealed 36 cases of measles in the region since the outbreak began, including 19 confirmed and 17 probable infections. The majority of these cases, 28 in total, have been reported in 2025, with 15 new cases emerging between April 28 and May 5.