Updated Provincial Recommendations for Measles Postexposure Prophylaxis
To: Ottawa Physicians and Nurse Practitioners
Date: March 24, 2025
From: Dr. Michelle Foote, Associate Medical Officer of Health
Subject: Updated Provincial Recommendations for Measles Postexposure Prophylaxis
Dear Colleagues,
The Ontario Immunization Advisory Committee (OIAC) has provided updated recommendations for measles post-exposure prophylaxis for individuals who are immunocompromised. See the summary and full statement on Public Health Ontario’s (PHO) Measles site. We anticipate an updated version of the At A Glance Measles: Post-Exposure Prophylaxis for Contacts will be posted to this site in the coming week.
For additional information on the assessment and management of suspect measles cases, please see OPH’s Public Health Alert from February 12: Measles Update and Resources for Health Care Providers.
For the latest information on the current outbreak of measles in Ontario, refer to PHO’s Enhanced Epidemiological Summary, available on PHO's Measles site. As of March 24, 2025, there are no known cases of measles among Ottawa Public Health residents in 2025.
If measles is suspected in a patient:
1. Provide the patient with a medical mask and place in a negative pressure room.
- In the absence of a negative pressure room, place the patient in a single patient room with the door closed. The door must stay closed, and the room must not be used for 2 hours after the patient leaves the room.
2. Obtain specimens for testing:
- NP swab, throat swab, and urine for measles PCR
- Diagnostic serology (Measles IgM and IgG) can be considered but is not required. Collection of samples for PCR testing is the most important component for diagnosing measles.
3. Contact Ottawa Public Health immediately to report the suspect case:
- Notify OPH at 613-580-2424 ext. 24224 from Monday to Friday 8:30 am to 4:30 pm or dial 3-1-1 after hours and ask for Public Health on-call.
- Reporting a suspect measles case should not be delayed pending lab results.
4. Instruct patient to isolate at home while results are pending.
Revised (April 11, 2025): Language on diagnostic serology edited for clarity and consistency.