MEMO: Increased Measles Activity in Ontario

Issued by: Dr. Jessica Jackman, MD MPH FRCPC FACPM DipABLM, Associate Medical Officer of Health
Date: February 25, 2025

Measles is a highly contagious and potentially severe viral infection. Ontario is seeing increased measles activity, due to a measles outbreak in southwestern Ontario (refer to page 3 for affected health unit areas). As of February 24th, 2025, Niagara region does not have any cases of measles, however the ongoing measles outbreak in southwestern Ontario, and its proximity to Niagara, poses health risks to our community. The purpose of this alert is to provide updated measles vaccination recommendations and review health care provider actions when measles is suspected.

Measles Vaccination Recommendations

For non-healthcare workers, if immunization status is unclear, vaccination is preferred over serology. This does not apply to specific occupational groups, such as healthcare workers, who require either documentation of immunization or serologic proof of immunity regardless of their birth year. Refer to PHO Measles-Serology for details.

Measles vaccination recommendations as of February 25, 2025

Continue to provide vaccinations as per the Publicly Funded Immunization Schedules for Ontario.

Measles vaccine recommendations may be subject to change in an outbreak situation or if new guidance from the Ontario Ministry of Health is released based on increased measles. Monitor Vaccinations for Measles - Niagara Region, Ontario for any updates to the recommendations provided below.
Use the General Vaccine Order Form to place an order for vaccine

Infants six to 11 months

One dose of MMR vaccine is recommended if an infant is travelling to areas (including within Ontario) and countries where disease is of concern
Two additional doses of measles-containing vaccine are required beginning on an individual’s first birthday – one dose of MMR vaccine at 1 year of age (at least four weeks after the previous dose) and one dose of MMRV vaccine between 4 and 6 years of age (preferably prior to school entry if they are four years of age)

Children and youth

The first dose of measles-containing vaccine is given at 12 months of age
A second dose is routinely given between 4 to 6 years of age
- Due to increased measles activity in the province, consider providing the second dose as soon as a child turns four years of age
- Please note, it is not recommended to provide the second dose of measles- containing vaccine prior to 4 years of age
Children who have not received measles-containing vaccine according to this timeline are recommended to receive two doses according to the Publicly Funded Immunization Schedules for Ontario

Pregnant patients

Live vaccines like MMR and MMRV are generally contraindicated during pregnancy. Please refer to the Canadian Immunization Guide for more details.

Make a strong recommendation to choose vaccination

Health care providers are a trusted source of information. Patients are more likely to choose to vaccinate when their health care provider makes a strong and confident recommendation. Therefore patients who otherwise would not be getting vaccinated may decide to receive measles-containing vaccine because of the trusted relationship with their doctor.
Please consider proactively reaching out to patients on your roster that are not vaccinated, due, or overdue for measles-containing vaccine. Patients may be able to access their immunization record for you using Immunization Connect.
Key message for patients:
- Recent cases of measles reported in Ontario are an important reminder to check your immunization records to make sure you’re up to date with all your vaccinations

Health Care Provider Actions When Measles is Suspected

Reporting

If you suspect measles in a patient please report it immediately to Niagara Region Public Health. Do not wait for laboratory confirmation. Contact the Infectious Disease Program at:
- 905-688-8248 or 1-888-505-6074 ext. 7330
- After-hours: 905-984-3690
Consider measles in your differential diagnosis if a patient presents with a fever, respiratory symptoms, conjunctivitis, and/or a maculopapular rash that begins on the face and spreads downwards (typically appears 3-5 days after onset of prodromal symptoms). This is particularly important if they have a history of recent travel to areas with increased measles activity, and/or are not fully vaccinated.

Infection Prevention and Control Practices

Patients with suspected measles should be placed under airborne precautions and promptly isolated in a single room with negative air flow (airborne infection isolation room or AIIR) and the door closed. If you do not have an AIIR, the patient should wear a surgical mask and be immediately placed in a single room with the door closed.
Measles virus can remain airborne for up to two hours. No further patients should be placed within the room for a two-hour period following use by an individual suspected to have measles.
You may consider giving patients with suspect measles the last appointment of the day.
Only immune staff should provide care to suspect cases of measles
Please ensure your office has enough PPE for airborne precautions

Testing

Specimen Collection:
- Indicate STAT on lab requisitions. Include travel history and vaccination status on the requisition.
- Recommended samples:
  - Nasopharyngeal and/or throat swab PCR (within 7 days of rash onset) AND urine PCR (within 14 days of rash onset)
  - Refer to PHO Measles-Diagnostic-PCR guidelines for details
- It is NOT recommended that serology be ordered as the only test for measles diagnosis. Refer to PHO Measles – Serology for details.
- To facilitate timely testing when needed, ensure specimen collection supplies, including viral swabs, are readily available. To order specimen collection supplies, use the PHOL Requisition for Specimen Containers and Supplies. See PHOL Kit and Test Ordering Instructions for more information.
Provide isolation guidance to the patient while test results are pending
- Please instruct patient to stay home and self-isolate from all public places such as childcare settings, schools, post-secondary educational institutions, workplaces, places of worship, sporting events, healthcare and other group settings; avoid contact with any non-household persons

More Information

Measles information for health care providers – Public Health Ontario
Contact the Infectious Disease Program at:
- 905-688-8248 or 1-888-505-6074 ext. 7330
- After-hours: 905-984-3690
Call the Vaccine Preventable Disease program at 905-688-8248 or 1-888-505-6074 ext. 7396. Please state that you are a health care provider and we will prioritize your call during times of high call volume.