OH&S Department: Spring 2025 Update (Measles – What You Need to Know)

Shared on behalf of the Occupational Health and Safety Department


Measles is a very contagious virus that can survive in the air or on surfaces for two hours. One infected person can infect 9 or 10 other unvaccinated close contacts. It can be transmitted by an infected person from four days prior to the onset of the rash to four days after the rash erupts.

Measles is becoming more prevalent in Ontario, with the number of cases being the highest it has been in 10 years. Although there are currently no cases of measles in Thunder Bay, we need to be aware of how to protect ourselves.

Occupational Health and Safety has recently reviewed all staff, to ensure they are in compliance with the mandatory requirement of either having laboratory evidence of proof of immunity to measles, or proof of two doses of the Measles, Mumps, Rubella vaccine.

Other ways we can protect ourselves is by ensuring we are up to date with N95 mask fit testing (see N95 mask fit information above). Staff should be performing Infection Control Risk Assessments on their patients (an evaluation of the interaction of the health care worker, the patient, and the patient environment to assess and analyze the potential for exposure to infectious disease) prior to each interaction with the patient, and wearing the appropriate PPE based on the Infection Control Risk Assessment and isolation signs posted for patients.