Measles

Measles spreads quickly from person to person through droplets from an infected person's mouth, nose and throat. These airborne droplets spread through talking, coughing or sneezing. The measles virus can also stay in the air for up to two hours after an infected person has left the enclosed area.

A person with measles can spread the virus from four days before a rash appears to four days after the rash appears.  

More information is available on the Measles Fact Sheet | English | French

Symptoms may start around seven to 21 days after exposure Generally, the illness lasts for about 10 days on average.

Symptoms include:

• Cough
• Runny nose
• Fever
• Red and watery eyes
• A red, blotchy rash. Typically beginning at the head and spreading down the body to the arms and legs, usually appearing three to seven days after becoming ill. The rash disappears in the same order of appearance (head to foot) in about four to seven days
• Sensitivity to light
• Small white spots with a white centre inside the mouth (Koplik spots)

Most people recover completely from measles but the infection can cause complications such as ear infections, lung infections (pneumonia), inflammation of the brain (encephalitis), death and permanent brain damage.

Measles can be serious in all age groups if you are not vaccinated. However, several groups are more likely to develop complications from measles infections:

• Infants and young children (under five years of age)
• Pregnant people who are unimmunized are at an increased risk of miscarriage or premature delivery and low birth weight of infant
• People with weakened immune systems 

Getting the measles (MMR) vaccine is the best way to protect yourself and others. 

Measles, Mumps and Rubella (MMR) vaccines are safe and provide long-lasting protection. Two doses of MMR vaccines are approximately 97% effective in preventing measles infection.

Recommendations for measles (MMR) vaccine

Infants under 12 months of age

Infants under 12 months of age are at the greatest risk for measles infection. Infants 6 to 11 months of age travelling to an area where measles is circulating can get vaccinated before travel. NOTE: Two additional doses of measles-containing (MMR) vaccine must be administered after the child turns 12 months to ensure long-lasting immunity to measles.

Children

Children receive two doses of measles-containing (MMR) vaccine for full protection.  As outlined in Ontario's routine immunization schedule, children typically receive their first dose of a measles-containing vaccine after their first birthday and the second dose between ages four to six.

Individuals born in 1970 or later

Individuals born in 1970 or later require two doses of measles (MMR) vaccine for protection if they did not have a measles infection. Those who attend post-secondary institutions or work in educational settings (licensed childcare centres or schools) are recommended to have immunity documentation, such as two doses of a measles-containing (MMR) vaccine, proof of immunity via a blood test or a record of confirmed measles infection.  

Individuals born before 1970

Individuals born before 1970 may have had measles infection, which provides lifelong immunity. If unsure and travelling to an area where measles is present, they may receive one dose of the measles (MMR) vaccine.

Health care workers and military personnel need to be immune against measles to work, regardless of birth year. This includes having documented proof of two doses of a measles-containing (MMR) vaccine, proof of immunity (blood test) or a record of confirmed measles infection.

Where to get vaccinated  

The measles (MMR) vaccine is available for children and adults at health care providers’ offices, some walk-in clinics and travel clinics.

York Region Public Health provides the measles (MMR) vaccine and other routine childhood immunizations required for school attendance at our community immunization clinics (by appointment only) for Junior Kindergarten to Grade 12 students.

Eligible individuals 12 months and older may get the measles (MMR) vaccine at a York Region Public Health community immunization clinic by appointment only. The measles (MMR) vaccine is free and is provided to those who are eligible or overdue and do not have access to vaccines through a health care provider.  

Vaccinating your child protects them and those around them who are not able to be vaccinated, such as young infants, those who are ill or have weakened immune systems, or pregnant individuals.

For more information, see the Measles, Mumps and Rubella vaccine fact sheet or speak with your health care provider.

If you think you have measles, it is important to:

• Isolate immediately by staying home (do not go to school or work) and avoid contact with others
• Call before going to going to a clinic or hospital, so they can prepare for your arrival to prevent the virus from spreading to others
• Wear a well-fitting, high-quality face mask when seeking medical care 

If you have been in contact with a person who has measles and do not have any symptoms:

• Call your health care provider to inform them of a measles exposure and confirm your immunization status as soon as possible. If you have never been vaccinated, a Measles, Mumps, and Rubella (MMR) vaccine is recommended within 72 hours of contact with a person with a measles infection
• Infants under six months of age, pregnant individuals who are not immunized and severely immunocompromised individuals may be eligible for preventive treatment within six days of contact with a person with measles infection
• Individuals with two doses of the Measles, Mumps, and Rubella (MMR) vaccine should monitor for symptoms as a precaution but do not need to take any other action. Adults born before 1970 may be at reduced risk as they are generally presumed to have acquired natural immunity to measles; however, consider obtaining a dose of MMR vaccine in consultation with their health care provider
• All individuals, regardless of vaccination history, who have been in contact with an infected person are advised to monitor for symptoms for 21 days after their last exposure

If you require more information, call Access York at 1-877-464-9675.

Measles is diagnosed with laboratory tests, including blood, urine and throat tests. Call your health care provider if you have symptoms or were exposed to measles. York Region Public Health will follow up with the diagnosed individual and exposed contacts when a measles case is confirmed. See “Seeking medical care and when to isolate” section above. 

There is no specific treatment for measles. Most people can recover at home. Hospitalization may be needed for severe infections. Vaccinating against measles is the best protection.

You can get revaccinated if you do not have vaccination records and cannot obtain them. You can contact your health care provider for more information. York Region parents/guardians can update and look up immunization records for school-aged children.

Measles is a reportable disease requiring all physicians who suspect or diagnose a patient with measles to report to York Region Public Health immediately. Please call us at 1-877-464-9675, ext. 73588, or after hours at 905-953-6478 (after 4:30 p.m., weekends, holidays).

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:

 Please use this form to order specimen collection kits from the Public Health Ontario Laboratory. 

Infection prevention and control 

Measles is a virus spread via the airborne route and close contact with respiratory secretions. It is one of the most infectious viruses known.  A person infected with measles can pass the virus infection to 12 to 18 others if they are not immunized or have natural immunity from a previous measles infection. 

Patients with suspected measles should be promptly isolated in a single room with negative air flow (airborne infection isolation room) with the door closed. If you do not have an airborne infection isolation room, the patient should wear a surgical mask and be immediately placed in a single room with the door closed. 

The measles virus can remain in the air for two hours. Therefore, no other patients should be placed in the same room for two hours afterwards. Patient movement should be limited unless absolutely required. Additional information on infection prevention and control measures can be found here. 

Post-exposure Prophylaxis

Close contacts of a confirmed case of measles may be eligible for post-exposure prophylaxis (PEP). PEP is given to provide protection and/or modify the clinical course of the disease for individuals who have no immunity and/or are at higher risk of severe outcomes.

York Region Public Health facilitates eligible contacts to receive PEP with a health care provider in the community and/or at a York Region vaccine clinic. PEP includes the administration of the Measles, Mumps and Rubella (MMR) vaccine or serum immunoglobulin (Ig), depending on the age and underlying health of the contact person. 

MMR Vaccine 

• Immunocompetent susceptible contacts six months of age and older who have no contraindications should be given the MMR vaccine within 72 hours of the exposure
• Important: If the MMR vaccine is given before 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 ensure long-lasting immunity to measles 
• Some adults born after 1970 and who have only received one documented dose of MMR vaccine may still be susceptible to measles, as a single dose of MMR vaccine has a vaccine effectiveness of between 85-95%. In terms of contact management, consideration should be given to offering adults a second dose of MMR
• Individuals born before 1970 are generally presumed to have natural immunity; however, consideration may be given to providing an adult born before 1970 with a single dose of MMR

Immunoglobulin 

• Immune globulin (Ig) is made from donated human blood plasma that contains antibodies to protect against infections including measles. Ig can provide immediate, short-term protection when given within six days of exposure. It can prevent infection or make the clinical course less severe. It is generally given to individuals who are unable to receive the measles vaccine
• Ig for measles PEP is recommended for susceptible, high-risk groups, including: 
  • Infants 0 to six months of age
  • Susceptible immunocompetent infants six to 12 months of age who are identified after 72 hours and within six days of exposure
  • Susceptible pregnant individuals (i.e., those without documentation of two doses of measles vaccine or immunity)
  • Immunocompromised individuals six months of age and older
    
    Note: Certain immunocompromising conditions make it unlikely for an individual to have developed or maintained protective levels of anti-measles antibodies, despite previous vaccination. This includes individuals with advanced HIV with severe immunosuppression and hematopoietic stem cell transplantation (HSCT) recipients. These individuals should be offered Ig as measles PEP within 6 days of exposure.

Other Resources:

• Key resources about measles cases and vaccination – Memo from Chief Medical Officer of Health – March 27, 2024 
• Measles Vaccine Guidance - March 11, 2024
• Confirmed Measles case, reminders for clinical assessment - March 1, 2024
• Measles Preparedness - February 20, 2024
• Measles Information for Clinicians (Public Health Ontario)
• Publicly Funded Vaccines Order Form
• Measles Vaccines: Canadian Immunization Guide (Public Health Agency of Canada)   
• NACI Recommendations for measles post-exposure prophylaxis