Measles

Health Care Worker Immunity:

• Confirm presumptive immunity for all health care workers to minimize the risk of transmission.
• Public Health Ontario recommends the only health care workers with presumptive immunity provide care to suspect/confirmed cases of measles.
  • Evidence of Presumptive Immunity:  For health care workers, this includes at least two doses of measles-containing vaccine received on or after their first birthday or laboratory evidence of immunity, regardless of year of birth. 

Patient Vaccination:

• Health care providers should be aware of the outbreak recommendations to ensure those planning to visit/travel to affected regions are vaccinated appropriately, and providers should also continue to offer routine or catch-up immunizations as per Ontario’s Publicly Funded Immunization Schedules (the Immunization Schedules). 
• Publicly Funded Immunization Schedules for Ontario (June, 2022)
• Routine and Outbreak-related Measles Immunization Schedules (May 2025) 

Differential:

• Include measles in differential diagnosis, including returning travellers with respiratory symptoms or rash.

Isolate Suspect Cases:  

• Isolate suspected measles patients promptly in a single room with negative air flow (airborne isolation room).
• If you do not have an airborne infection isolation room, the patient should wear a mask and be placed in a single room.
• In either case, the door should remain closed and only measles-immune health care workers should attend to these patients.

Laboratory Testing:

• Laboratory confirmation should be sought in all suspected cases.
• Ensure that appropriate specimens have been collected, including specimens for viral detection (e.g., nasopharyngeal swab and urine sample), as viral identification should be prioritized and attempted for all cases of suspect measles.
• Refer to the Public Health Ontario (PHO) laboratory test information sheet for more information.

Virus Isolation (culture) and Molecular RNA (PCR) Detection: 

• Testing of multiple specimens increases the overall sensitivity. 
• Specimens for virus isolation or RNA (i.e., PCR) detection include: 
  • Nasopharyngeal swab or aspirate and/or throat swabs collected within 7 days of rash onset; and 
  • Urine (minimum 50 mL collected in a sterile container) collected within 14 days of rash onset.

Serology:

• It is NOT recommended that serology be ordered as the only test for measles diagnosis. 
• IgM serology for measles is most useful in primary infection and may be of limited use in an individual who has a history of measles vaccination.

Laboratory Services – Public Health Ontario (PHO):

• Measles – Diagnostic – PCR
• Measles – Serology  

Report IMMEDIATELY:

• Report all suspect cases of measles to TBDHU immediately.
• Do not wait for laboratory confirmation.
• Call (807)625-8318 or toll-free 1-888-294-6630, ext. 8318 (Monday-Friday, 8:30am to 4:30pm).
• After hours and on weekends/holidays call Thunder Bay Answering Service at (807) 624-1280.

Review Additional Resources:

• See below for other valuable resources. 
• Sign up online for the health care provider electronic updates and alerts
• This page will updated as new inform becomes available.