Health Care Professionals

Fact sheets

• Measles
• Measles Exposure
• Measles, Mumps, and Rubella (MMR) Vaccine
• Measles, Mumps, Rubella and Varicella (MMRV) Vaccine
• Self-Isolation

FAX abouts

Measles in Durham Region
March 6, 2026

News releases

• Health Department investigating additional case of measles in Durham Region
  March 18, 2026
• Health Department investigating two new confirmed cases of measles in Durham Region
  March 8, 2026
• Health Department investigating confirmed case of measles in Durham Region
  March 6, 2026

Clinical signs and symptoms of measles are:

• Fever greater than or equal to 38.3 degrees Celsius oral and
• Generalized maculopapular, erythematous rash for at least three days, and
• At least one of the following:
  • Cough
  • Runny nose (coryza)
  • Red eyes (conjunctivitis)

Measles is characterized by a prodrome of fever (greater than or equal to 38.3 degrees Celsius oral), cough, coryza (runny nose) and conjunctivitis which usually begin 10 to 12 days after exposure (range seven to 21 days).

Koplik spots (tiny blue-white spots on the buccal mucosa) may also be present during the prodromal period.

Three to seven days after the onset of prodromal symptoms, a red maculopapular, non-itchy rash appears on the face and then spreads downward to the neck, trunk, arms, legs and feet. The rash usually appears about 14 days after exposure (range seven to 21 days).

Individuals who have received one or two doses of measles-containing vaccine may develop an infection with milder symptoms.

Unvaccinated or individuals who have not had two doses of measles-containing vaccine are at increased risk of measles.

The following individuals are at increased risk of more severe measles disease:

• Immunocompromised individuals, especially those who have severely impaired cell-mediated immunity, such as individuals who have recently undergone bone marrow transplantation, individuals with primary T-cell dysfunction, individuals with acute lymphoblastic leukemia, and individuals living with AIDS in whom measles can be severe, atypical and prolonged.
• Individuals with other forms of immunosuppression (e.g., other forms of malignancy), and those receiving high dose steroids or other types of immunosuppressive drugs.
• Children younger than five years of age and adults 20 years of age and older.
• Malnourished children, particularly those with vitamin A deficiency.
• Susceptible pregnant women in who infection is associated with risk of fetal loss and prematurity; there is no evidence that infection leads to congenital defects.

• Measles PCR testing 
• Measles serology testing

Contact Durham Region Health Department prior to collecting specimens. Courier service will be arranged to facilitate timely shipping and testing of specimens.

1. Promptly isolate any suspect or confirmed measles patients in a single clinic room or in a single room with negative air flow (airborne infection isolation room) if available.
2. Collect the following samples within 7 days of rash onset and send separately from routine specimens:
   • Throat swab diagnostic PCR
   • Nasopharyngeal (NP) swab diagnostic PCR
   • Urine diagnostic PCR
   • Measles serology (IgG and IgM) - May provide additional diagnostic value, however it is not mandatory and the decision to collect blood for serology remains at the discretion of the health care provider.
3. Clearly mark "STAT – Suspect case of measles" on each laboratory requisition and on the outside of the specimen bag, include a PHO Laboratory Requisition form with following information:
   • Symptoms
   • Date of illness onset
   • Exposure history
   • Travel history
   • Vaccination history
4. Call Durham Region Health Department to notify of suspect case and to assist with sending samples to the Public Health Ontario Laboratory (PHOL) - Toronto site for STAT measles testing by calling 905-668-4113, ext. 2996 or after hours at 905-576-9991.
5. Store specimens in the fridge between 2 to 8 degrees Celsius and ship to PHOL on ice packs.
6. Instruct your patient to isolate at home after leaving your clinical facility and that Durham Region Health Department will contact them for further direction and support. See Facts about... Self-Isolation.
7. PCR is the preferred diagnostic test during acute stage of illness due to higher sensitivity compared to measles serology.
8. IgM serology should not be the only diagnostic test relied upon for the diagnosis of measles. Diagnosis for a symptomatic patient requires additional samples (e.g., throat swab and urine) for testing by PCR.

Diagnostic laboratory tests for detection of measles

MMR vaccine OR immune globulin (Ig) may be used for measles post-exposure prophylaxis in susceptible individuals.

MMR vaccine

Susceptible immunocompetent contacts six months of age and older who have no contraindications should be given MMR vaccine within 72 hours of the exposure.

Immune Globulin (IMIg and IVIg)

IMIg/IVIg, if administered within six days of exposure, may provide some protection or modify the clinical course of disease among susceptible contacts. As the efficacy of Ig prophylaxis decreases with time from exposure, prompt administration of Ig is encouraged, if needed. Ig should be reserved for susceptible contacts at higher risk of disease severity.

Susceptible high-risk contacts include:

• Immunocompromised individuals *See Recommendations: Measles post-exposure prophylaxis for individuals who are immunocompromised due to disease or therapy;
• Susceptible pregnant individuals;
• Susceptible infants less than six months of age
• Susceptible immunocompetent infants six to 12 months of age who are identified after 72 hours and within six days of a measles exposure.

Canadian Immunization Guide Measles PEP Table

Individuals who receive an Ig as PEP should continue to monitor for signs and symptoms of measles for 28 days after the last exposure.

• Measles vaccines: Canadian immunization guide
• Updated NACI recommendations for measles post-exposure prophylaxis
• Blood products, human immunoglobulin and timing of immunization: Canadian immunization guide

Vaccine

• Ontario's routine immunization schedule
• Measles vaccines: Canadian immunization guide

If MMR vaccine is given prior to 12 months of age as PEP, two additional doses of measles-containing vaccine must be administered after the child is 12 months of age to provide long lasting immunity to measles.

When MMR vaccine is offered 72 hours after exposure, it will not be as effective for PEP, however it provides an opportunity to update immunizations, starting and completing a two-dose series that will provide long-term protection from any subsequent measles exposures.

MMR vaccine: Other considerations

• If a dose given for travel is administered on or after the first birthday and is separated from any previous live attenuated vaccine by at least 28 days, the dose is valid and will meet school-entry immunization requirements in Ontario.
• If a patient’s immunization records are unavailable, immunization with measles-containing vaccine is preferable to ordering serological testing to determine immune status. This avoids the potential for false positive and/or false negative results, reduces the risk of missed opportunities for immunization.
• It is safe to give additional dose of MMR vaccine to those who are already immune.
• Routine serological testing to determine immunity in healthy individuals is not routinely recommended.

• All health care workers (HCWs) should have documented immunity to measles.
• Only HCWs (regardless of age) with presumptive immunity to measles should provide care to patients with suspect/confirmed measles, including:
  • At least two doses of measles-containing vaccine received on or after their first birthday.
    or
  • Laboratory evidence of immunity.
• All HCWs should wear a fit-tested, seal-checked N95 respirator when enter the room and/or caring for a patient with suspect/confirmed measles.
• All patients with suspect or confirmed measles must be isolated in a single room with negative air flow (airborne infection isolation room) with the door closed, if available.
• In addition to the use of Routine Practices, additional personal protective equipment (PPE) such as gloves, gowns and eye protection and facial protection may be added as required based on risk assessment as per Acute Respiratory Infection Precautions (previously known as Droplet and Contact Precautions) practices.
• Where possible, all procedures should be conducted in the separate patient room with the patient wearing a medical mask, if tolerated.
• Schedule the patient visit to minimize exposure of others (e.g., at the end of the day), and ensure the patient arrives wearing a medical mask and an appropriate room (airborne infection isolation room, if available) is available to place the patient in immediately upon arrival.
• After the patient leaves, the door to the room where the patient was examined must remain closed with signage to indicates that the room is not to be used. Allow sufficient time for the air to change in the room and be free of respiratory particles before using the room for non-immune individuals (two hours is a conservative estimate if air changes are not known). For institutional settings, this time period can be reduced depending on the number of room air changes per hour.
• Conduct routine cleaning of the room and equipment once sufficient time has elapsed to ensure adequate air exchange has occurred in the room.

Interim IPAC recommendations and use of PPE for care of individuals with suspect or confirmed measles

Provincial Infectious Diseases Advisory Committee, Routine Practices and Additional Precautions in All Health Care Settings, 3rd Edition

• Measles: For health professionals (Public Health Agency of Canada)
• How to recognize and respond to measles