The MUHC says there have been no reports of measles transmission so far since an employee with the virus worked at the Glen site between March 23 and 27 but that they are waiting on some test results and remain on alert.
Infectious diseases specialist Dr. Marie-Astrid Lefebvre says they are not too concerned because the employee in question had limited contact with the public and patients and that the majority of the population has been immunized.
Lefebvre said they did not know the exact number of people who could have been exposed.
The cut-off date for the incubation period is April 17 and the MUHC is also waiting on test results in the next 48 hours for some whose immunization status is unknown.
The employee worked in the cardio surgery unit, infectious diseases clinic and the cardiovascular, heart failure and heart transplant clinic during that period.
Lefebvre said the employee displayed very vague symptoms and the classic rash only showed up five days later, having likely contracted the virus during a trip to the Caribbean three weeks earlier.
Lefebvre said the employee was vaccinated as per MUHC protocol but that for a small percentage of people, it doesn't work or becomes less effective over age and time.
The MUHC initiated its protocol to alert patients and staff including registered letters.
Lefebvre said that to her knowledge, this was the first such case at the MUCH and that the chance of it happening again is low.
Lefebvre says they could not identify the employee for confidentiality reasons.