Updated June 2025
IMPORTANT: health care providers should promptly isolate any patient with suspect or confirmed measles in a single room with negative air flow (airborne isolation room) if available. Further details included below.
Immediately report all suspect or confirmed cases of measles infection to Toronto Public Health (TPH) at 416-392-7411 during business hours (8:30 am to 4:30 pm, Monday to Friday) or 311 after hours.
The measles virus is spread via the airborne route and close contact with respiratory secretions. It is one of the most highly infectious viruses known with greater than 90% secondary attack rates among susceptible persons.
For information on the epidemiology of measles in Toronto see TPH’s Measles fact sheet.
Clinically compatible signs and symptoms are characterized by:
Most people exposed to measles become symptomatic after 10-14 days. Incubation period ranges from seven to 21 days. Cases are infectious from one day before the start of the prodromal period, which is usually about four days before rash onset, to four days after onset of rash. Exclusion for measles exposure begins five days after first exposure due to the possibility of transmission before symptoms begin.
Follow PCR testing information for Measles from Public Health Ontario.
NOTE: Priority specimens for measles testing must be packaged separately from routine specimens – mark STAT on the outside of the package.
Ensure your office has specimen containers and supplies available for testing. Confirm the expiry dates on the specimen containers (e.g., swabs). Kits can be ordered from PHOL.
Measles PCR is a diagnostic test for the detection of viral RNA in clinical specimens collected from patients suspected of having Measles and is useful during the early phase of the disease following symptom onset.
Measles PCR is the preferred testing method during periods of significant community transmission such as the current multi-jurisdictional outbreak. Measles serology testing may provide additional diagnostic value, however blood collection may cause additional health care visit and community exposure and therefore is not mandated. The decision to collect blood for serology remains at the discretion of the health care provider.
Testing for immune status (IgG) is not routinely recommended for unvaccinated, under-vaccinated individuals, and unknown vaccination status. Measles-containing vaccine should be offered as the ideal protective measure in accordance with Canadian Immunization Guide.
For suspected cases of Measles, contact TPH prior to collecting specimens.
On each laboratory requisition for virus detection (PCR) or diagnostic serology clearly mark “suspect case of measles.” All requisitions should contain the following information: patient’s symptoms and date of onset, exposure history, travel history (if any) and vaccination history. The diagnostic tick box should also be marked. Specimens must be stored and shipped cold.
Ensure the case has been reported to TPH as per above.
Note: A negative PCR result should not be used to rule out measles and needs to be interpreted along with serology, symptoms, exposure history and vaccination status. In certain situations, such as when there is a high index of suspicion for measles (e.g., compatible illness in a returned traveller or contact with a laboratory-confirmed case) it may be warranted to test beyond the above time periods when specimens could not be collected earlier in the illness. This can be discussed with Toronto Public Health (TPH) on a case-by-case basis.
Contact the Public Health Ontario (PHO) Laboratories customer service at 416-235-6556 or 1-877-604-4567 if you have any questions.
NOTE: Ontario is currently experiencing a measles outbreak. In addition to the routine measles vaccination recommendations, see Outbreak Related Measles Immunization Strategy.
Publicly funded MMR vaccine can be provided based on the following recommendations:
Age Group | MMR Vaccine Recommendations |
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Infants and children NOT travelling |
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Infants and children travelling to areas where measles is circulating |
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Born before 1970 in Canada |
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Born in 1970 or later |
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All others |
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*MMR is a live virus vaccine. Two live virus vaccines can be given on the same day or at least 28 days apart. The exception is with MMRV and MMR vaccine which must be given six weeks apart according to the Immunization of School Pupils Act. MMR and Var may be given at the same visit if required.
#Preschool children who are given their second MMR before 4-6 years of age can then receive their second varicella-only vaccine at age 4-6 years (not MMRV).
NOTE: Measles-susceptible individuals who are pregnant should wait until after giving birth to get vaccinated with MMR vaccine. Susceptible individuals who are breastfeeding can be vaccinated with MMR vaccine. Pregnancy should be delayed by at least four weeks following vaccination with MMR vaccine.
Source: Ontario’s Publicly Funded Immunization Schedule, Canadian Immunization Guide.
For prevention of measles transmission in health care settings, all employees (e.g., nurses, physicians, support staff) should ensure that they are immune to measles. In the event of a measles exposure, employees will be excluded from work from five to 21 days post measles exposure unless they can provide proof of immunity regardless of their year of birth. Proof of measles immunity includes:
Population | Time since exposure to measles ≤ 72 hours | Time since exposure to measles 73 hours to six days |
---|---|---|
Susceptible infants zero to six months of age | IMIg (0.5 mL/kg) | IMIg (0.5 mL/kg) |
Susceptible immunocompetent infants six to 12 months of age | MMR vaccine | IMIg (0.5 mL/kg) |
Susceptible immunocompetent individuals 12 months of age and older | MMR vaccine series | MMR vaccine series |
Susceptible pregnant individuals | IVIg (400 mg/kg) or IMIg (0.5 mL/kg), limited protection if 30kg or more |
IVIg (400 mg/kg) or IMIg (0.5 mL/kg), limited protection if 30 kg or more |
Susceptible immunocompromised individuals six months of age and older | IVIg (400 mg/kg) or IMIg (0.5 mL/kg), limited protection if 30kg or more |
IVIg (400 mg/kg) or IMIg (0.5 mL/kg), limited protection if 30 kg or more |
Individuals with confirmed measles immunity | No PEP required | No PEP required |
Airborne precautions are used in addition to Routine Practices for patients known or suspected of having measles. Additional personal protective equipment (PPE) such as gloves and gowns may be added as required based on risk assessment as per Routine Practices.
In a clinical office setting, follow the most up to date provincial guidance:
In an acute care setting, promptly isolate the patient with suspect or confirmed measles in a single room with negative air flow (airborne isolation room) and the door closed. Precautions should be in place for four days after the start of the rash and for the duration of illness in immunocompromised patients.
Patient movement should be curtailed unless absolutely necessary and then only conducted with the patient wearing a surgical mask.
Ontario PPE Supply Portal – To order N95 respirators and other PPE.
Routine Practices and Additional Precautions in All Health Care Settings (PIDAC)
Immediately report all suspect or confirmed cases of measles infection to TPH at 416-392-7411 during business hours (8:30 am to 4:30 pm, Monday to Friday) or 311 after hours.