Measles Exposures in Ontario
Ongoing measles transmission in Ontario is impacting multiple public health units. Detailed information on measles cases in Ontario can be found in the Measles in Ontario Enhanced Epidemiological Summary.
For each measles case reported in Ontario, a public health investigation is completed to identify places where people may have been exposed to the measles virus.
Individuals who are not protected against measles AND who were in places where they may have been exposed to a case of measles on the following places and dates of possible exposure should check the website for their local public health unit for more information.
Getting vaccinated is the best way to protect yourself against measles.
In response to the current outbreak, in addition to routine immunizations, some public health units are offering early doses of measles vaccine (i.e., a dose of MMR vaccine for infants 6 to 11 months; a second dose of measles-containing vaccine before the age of 4) in affected regions and communities where the risk of exposure to measles is higher. Please see Routine and Outbreak-related Measles Immunization Schedules for more information.
The information on this webpage is updated on Tuesdays, or the next business day following a holiday. Please check your local public health unit website for updated information.
On this page:
- Places and dates of exposure to a case of measles
- What is measles?
- What to do if you are exposed to measles
Places and dates of exposure to a case of measles
Places visited by recent measles cases while infectious have been identified. Individuals who were in the following places during the dates and times specified should contact their local public health unit if they are not protected against measles. See the section What to do if you are exposed to measles to find out more.
These exposure sites have been compiled from public advisories issued by public health units and will be updated regularly, as the information may change as new cases are identified and current exposures become out of date. Please note: this list includes only known exposure sites and there may be sites that have not yet been identified.
Last updated on on July 29, 2025
Durham Region Health Department
| Exposure Location |
City/Town |
Exposure Dates and Times |
Monitor for Symptoms Until |
|---|---|---|---|
|
Salem United Reformed Church |
Bowmanville |
July 20 between 3:00 PM and 6:30 PM
July 20 between 9:30 AM and 1:00 PM |
August 10 |
| Exposure Location |
City/Town |
Exposure Dates and Times |
Monitor for Symptoms Until |
|---|---|---|---|
|
Chi-Cheemaun ferry |
n/a |
July 21 departure at 3:30 PM July 17 departure at 11:00 AM |
August 11 August 7 |
|
Chi-Cheemaun ferry |
n/a |
July 21 departure at 1:15 PM July 17 departure at 1:15 PM |
August 11 August 7 |
Hamilton Public Health Services
| Exposure Location |
City/Town |
Exposure Dates and Times |
Monitor for Symptoms Until |
|---|---|---|---|
|
Ellen Fairclough Building - Service Ontario |
Hamilton |
July 9 between 3:30 PM and 7:00 PM |
July 30 |
|
Upper Gage Clinic and Gage Pharmacy |
Hamilton |
July 9 between 11:30 AM and 2:30 PM |
July 30 |
|
Costco – Ancaster |
Hamilton |
July 7 between 3:00 PM and 8:00 PM |
July 28 |
|
Service Ontario |
Hamilton |
July 7 between 1:00 PM and 3:30 PM |
July 28 |
| Exposure Location |
City/Town |
Exposure Dates and Times |
Monitor for Symptoms Until |
|---|---|---|---|
|
St. Marys Memorial Hospital |
St. Marys |
July 14 between 8:55 AM and 11:35 AM |
August 4 |
| Exposure Location |
City/Town |
Exposure Dates and Times |
Monitor for Symptoms Until |
|---|---|---|---|
|
Canadian Tire |
Strathroy |
July 16 between 11:00 AM and 1:30 PM |
August 6 |
|
Real Canadian Superstore |
Strathroy |
July 15 between 11:00 AM and 1:30 PM |
August 5 |
|
Walmart |
Strathroy |
July 14 between 11:00 AM and 1:30 PM |
August 4 |
|
Grace Canadian Reformed Church |
Kerwood |
July 13 between 2:30 PM and 6:00 PM |
August 3 |
|
Hully Gully |
London |
July 10 between 9:00 AM and 12:00 PM |
July 31 |
Southwestern Public Health Unit
| Exposure Location |
City/Town |
Exposure Dates and Times |
Monitor for Symptoms Until |
|---|---|---|---|
|
Tillsonburg District Memorial Hospital Emergency Department |
Tillsonburg |
July 22 between 3:57 PM and 6:35 PM |
August 12 |
Sudbury & District Health Unit
| Exposure Location |
City/Town |
Exposure Dates and Times |
Monitor for Symptoms Until |
|---|---|---|---|
|
Chi-Cheemaun ferry |
n/a |
July 21 departure at 3:30 PM |
August 11 |
|
Chi-Cheemaun ferry |
n/a |
July 21 departure at 1:15 PM |
August 11 |
What is measles?
Measles is a respiratory infection that is highly contagious. Individuals with measles spread the virus by coughing or sneezing into the air. It can also be transmitted by touching your eyes, nose, or mouth after touching an infected surface. Symptoms of measles include fever, cough, runny nose, red watery eyes, and a red blotchy rash.
What to do if you are exposed to measles
If you are protected against measles, it is very unlikely that you will develop the disease. As a precautionary measure, watch for the onset of measles symptoms until 21 days after the date of exposure (see Places and dates of possible exposure to a case of measles) to find out more.
People are considered protected if they have at least one of the following:
- Proof of vaccination with two valid doses of measles-containing vaccine (e.g. MMR vaccine)
- Blood work showing antibodies to measles
- Documentation of prior laboratory-confirmed measles infection
- Are born before 1970 (with the exception of health care workers)
- All health care workers require evidence of vaccination with two valid doses of measles-containing vaccine or bloodwork suggestive of immunity (measles IgG reactive) regardless of year of birth
If you do not have any of the above, you are not protected against measles.
If you think you have been exposed and you are not protected against measles or if you are unsure about your immunization history:
- If you attend or work at a school, childcare, or healthcare setting, you MUST stay home and contact your local public health unit for further direction.
- If you have had no doses of MMR vaccine, stay at home and contact your local public health unit for further direction.
- If you have had one dose of MMR vaccine, call your healthcare provider or local public health unit to receive an additional dose of MMR vaccine. Notify your healthcare provider of your exposure so that they can take appropriate precautions to limit the spread of measles. Unless you work in a healthcare setting, you can immediately return to work, school, or daycare after you get a second dose of measles-containing vaccine.
- If you (or a family member) are at high risk of complications as listed below, contact your healthcare provider or local public health unit to discuss options to reduce the risk of measles infection through vaccination or a product called immunoglobulin. For these to be effective, they must be given very soon after exposure.
- Babies under one year age who have not received measles vaccine
- People with a severely weakened immune system
- Pregnant individuals who are not protected against measles
- If you are uncertain about your vaccination status, call your healthcare provider or your local public health unit to determine if you have received an MMR vaccine in the past.
- Watch for the onset of measles symptoms until 21 days after the date of exposure (see Places and dates of possible exposure to a case of measles).
- If you develop symptoms and need medical care, call ahead before you visit the doctor, clinic, or hospital to inform them of your exposure to measles so they can prepare for your arrival and take appropriate precautions.
- If you develop symptoms and do not need medical care, call your local public health unit.
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