Updated April 2024

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, and order the following tests: Measles PCR (nasopharyngeal (NP)/throat swab and urine specimen) and Measles Serology. 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:

  • fever
  • generalized maculopapular, erythematous rash for at least three days, and
  • at least one of: cough, coryza or conjunctivitis

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.

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 .

Diagnostic laboratory testing is indicated for individuals who have a clinical syndrome and history compatible with measles (e.g., travel or exposure to a case) and should include both measles virus detection by PCR (NP/ throat swab and urine) and diagnostic serology.

Specimen documentation and transport

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.

Measles virus detection by PCR

  • NP or throat swab: collected using Viral Transport Media (pink liquid medium) within seven days after rash onset; AND
  • Urine: minimum volume of 50 mL of urine collected within 14 days after rash onset.

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.

Diagnostic serology

Acute serology

A blood specimen (5ml) in serum separator tube (SST) for measles antibodies (IgM and IgG separately) collected at the first visit (ideally within seven days after rash onset). The requisition should be clearly marked “acute measles serology”.

Note: Diagnostic laboratory testing on well persons who have recently received measles-containing vaccine as part of the routine schedule or in advance of planned travel is not indicated.

Contact the Public Health Ontario (PHO) Laboratories customer service at 416-235-6556 or 1-877-604-4567 if you have any questions.

More information

MMR Vaccine Eligibility & Recommendations 

Measles continues to spread globally and is often travel-related. To prevent the spread of measles, one dose of MMR vaccine provides about 85% protection and two doses provide greater than 95% protection.

Publicly funded MMR vaccine can be provided based on the following recommendations:

Age Group MMR Vaccine Recommendations
Infants and children NOT travelling
  • Give one dose of MMR vaccine on or after the child’s first birthday.
  • Give MMRV vaccine as the second dose at age 4-6 years.*#
  • Where possible, give second dose of MMRV closer to age 4 than age 6.
Infants and children
travelling to areas where measles is circulating
  • Infants: MMR vaccine can be given early at 6-11 months of age. Two additional doses of measles containing vaccine are still required after the first birthday.
  • Preschoolers: Consider giving the second dose of MMR vaccine earlier than age 4-6 years
  • Ideally, give measles vaccine at least two weeks before travel.
Born before 1970 in Canada
  • Generally considered to have natural immunity since measles was circulating in Canada before 1970. Some of these individuals may be susceptible.
  • Individuals who work in a health care setting must show proof of immunity (record of two doses of MMR vaccine OR serology).
  • Post-secondary students and travellers should consider getting at least one dose of MMR vaccine.
Born in 1970 or later
  • If unknown status, give two doses of MMR vaccine at least 28 days apart.
  • If client only had one dose of MMR vaccine, give the second dose of MMR vaccine at least 28 days after the first dose.
  • If client had two doses of MMR vaccine, consider fully immunized – no serology required.
All others
  • All Ontarians, regardless of date of birth, are eligible for two publicly funded doses of measles-containing vaccine based on the health care provider’s clinical judgment and the needs of the patient (e.g., health care worker, post-secondary student, planning to travel where measles is circulating).
  • Note: Vaccination over serology is generally preferred.


*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.

Health care settings

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:

  • documentation of receipt of two doses of measles-containing vaccine on or after the first birthday, with doses given at least four weeks apart, or
  • laboratory evidence of immunity.

More information

Summary of updated measles post-exposure prophylaxis (PEP) recommendations for susceptible contacts

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)
IMIg (0.5 mL/kg), limited protection if 30kg or more
IVIg (400 mg/kg)
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)
IMIg (0.5 mL/kg), limited protection if 30kg or more
IVIg (400 mg/kg)
IMIg (0.5 mL/kg), limited protection if 30 kg or more
Individuals with confirmed measles immunity No PEP required No PEP required

Reference and more information

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:

  • Make every effort to see the patient at the end of the day if clinical status allows.
  • Quickly triage the patient out of the common waiting areas and move the patient to an examining room. If possible, the patient should enter and exit through a separate entrance and go directly in and out of the examination room.
  • Provide a surgical face mask for the patient to wear at all times while in all areas of the clinical office. For practices with a large pediatric component, pediatric masks are now available for purchase.
  • Keep the door to the treatment/exam room closed; open a window in the room if possible.
  • Visitors and staff should not enter the room unless they have documented immunity to measles (see Vaccination).
  • All health care workers, regardless of presumptive immunity to measles, are to wear a fit-tested, seal-checked N95 respirator when providing care to a patient with suspect or confirmed measles.
  • Place alert signage for staff on the closed door.
  • Allow sufficient time for the air to change in the room and be free of droplet nuclei before using the room for other patients – two hours is a conservative estimate of the time required. The time required may be minimized if the patient has worn a surgical mask consistently.
  • Routine cleaning for the room or equipment is sufficient after examining a patient under Airborne Precautions.

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.

More information

Ontario PPE Supply Portal  – To order N95 respirators and other PPE.

Interim IPAC Recommendation and Use of PPE for Care of Individuals with Suspect or Confirmed Measles.

Routine Practices and Additional Precautions in All Health Care Settings (PIDAC)

  • There is no specific treatment for measles.
  • Medical care is supportive to help relieve symptoms and address complications such as bacterial infections.

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.