'It is critical we work together' says chief medical officer of health
Ontario is grappling with its largest measles outbreak in over a decade, with 350 confirmed cases since 2024, including 31 hospitalizations. In just the past several weeks, 173 new cases have emerged, prompting an urgent warning from Dr. Kieran Moore, Ontario’s chief medical officer of health. “It is critical we work together to mitigate further spread of this vaccine-preventable disease.”
Health officials report that over 96 per cent of cases involve individuals who are either unimmunized or have unknown immunization status, with most infections occurring in southwestern Ontario among unvaccinated people. The majority of cases stem from community exposure or travel-related transmission.
Workplace risk and precautions
With measles spreading rapidly, workplace health and safety professionals must take proactive steps to protect workers, particularly in high-risk environments like healthcare, childcare, education, and public-facing industries. Measles is highly contagious, spreading through respiratory droplets and lingering in the air for up to two hours after an infected person has left an area.
Employers should consider the following safety measures:
- Verifying immunization records for employees, especially in high-contact settings.
- Encouraging vaccination among those who are unimmunized or uncertain of their status.
- Enhancing infection control measures, such as isolating symptomatic individuals and implementing strict cleaning protocols.
- Educating workers about measles symptoms, which include fever, cough, runny nose, red eyes, and a distinctive rash that typically appears several days after initial symptoms.
Vaccination: The most effective protection
“Vaccination is the most effective way to limit the spread of measles and protect yourself and your loved ones,” says Dr. Moore. He highlights the longstanding safety and effectiveness of the measles, mumps, and rubella (MMR) vaccine.
“The MMR vaccine has been in use for more than 50 years and is proven to be one of the safest and most effective vaccines available. Children who are fully immunized with two doses of the measles vaccine are nearly 100 per cent protected, with one dose estimated to be up to 95 per cent protective.”
As part of Ontario’s routine vaccination schedule, children should receive:
- First dose at 12 months old
- Second dose between four and six years old
Adults who are unsure of their immunization status should contact their healthcare provider or local public health unit.
What to do if exposed
Measles is not just highly contagious—it can lead to severe health complications, including pneumonia, respiratory failure, swelling of the brain, and, in rare cases, death.
“If you think you or a family member has been exposed to measles, please contact your health care provider immediately,” says Dr. Moore. “Before any visit, be sure to call ahead to let them know that you are coming and that you suspect that you may have measles so appropriate precautions can be taken.”
Ontario’s response to the outbreak
Public health authorities are working closely with healthcare providers to contain the outbreak.
Ontario health and safety professionals play a crucial role in preventing workplace transmission. Ensuring employees are vaccinated, informed, and protected will help contain the outbreak and safeguard public health.
For more information on measles prevention and workplace safety guidelines, contact your local public health unit or visit the Ontario Ministry of Health’s website.
