Measles

Measles is a respiratory disease caused by a highly contagious virus. It is a virus that is easily spread through the air, from person to person, through breathing, coughing or sneezing. Measles is the leading cause of vaccine-preventable deaths in children worldwide.

Information on measles for health care providers can be found on the Health Care Providers page. 

On this page:

How measles spreads

  • If you come into contact with someone who has measles, you could develop symptoms about 7 to 21 days later.
  • Measles can spread if you have shared the same room or airspace with a person who has measles.
  • A person is contagious from four days before the rash begins until four days after the rash has appeared.
  • Measles can remain in the environment for up to two hours after an infected person has left the area.

Symptoms of measles

  • Measles begins with cold-like symptoms such as a runny nose, cough, sore throat, fever, and red, watery eyes that are sensitive to light.
  • Small white spots sometimes appear in the mouth and back of the throat.
  • 3 to 7 days later, a red blotchy rash appears on the face and spreads to the rest of the body.
  • The rash lasts 4 to 7 days.
  • Serious complications can occur such as:
    • One in ten children will develop an ear infection or bronchopneumonia.
    • One in one thousand children will develop an infection of the brain (encephalitis).
    • One or two out of a thousand children will die as a result of measles.

If you have symptoms, please stay home and call your health care provider to guide your next steps. If you do not have a health care provider, you can call 811. You can also use the measles self-assessment tool.

Measles Self-Assessment Tool

Measles exposure 

If you think you have been exposed to measles:

  • Stay home if you are ill to avoid passing germs to others.
  • Seek medical attention when exposure is suspected and before any symptoms appear.
  • Those who notice possible symptoms are asked to stay home and call ahead before visiting a clinic.

If you have been exposed to a person with measles and are not fully protected against measles, you are at risk of developing the disease.

If you think you have been exposed to measles, click the button to access the measles self-assessment tool to guide your next steps.

Measles Self-Assessment Tool

For further information please call Public Health at 519-575-4400.

Prevent measles with vaccination 

Getting vaccinated is the best way to protect yourself against measles.

Routine vaccination recommendations for children

  • Current Ontario recommendations are that children receive two doses of a measles vaccine:
    • First dose on/after their first birthday.
    • Second dose at 4 to 6 years old.
    • For some infants 6 to 12 months of age, one dose of the measles vaccine can provide protection if there is a risk of exposure (e.g., travel to an area where measles activity is occurring).

Routine vaccination recommendations for adults 

  • Born in 1970 or later:
    • Should have at least one dose of the measles vaccine.
    • A second dose is recommended for international travellers, adults who are travelling to areas of Canada where measles activity is occurring and post-secondary students.
  • Born before 1970:
    • Adults born before 1970 are considered to be immune to measles based on probable exposure earlier in life.
    • One dose of the measles vaccine is recommended for international travellers, adults who are travelling to areas of Canada where measles activity is occurring and post-secondary students.
  • Health care workers or military personnel:
    • Two doses of the measles vaccine are recommended regardless of year of birth (or laboratory evidence of measles immunity).

How can I find my vaccination records?

There are a few ways to locate vaccination records:

  • Look for your yellow vaccination record (also known as the immunization card). Measles vaccines are listed as “MMR”, “M” or “MMRV” on vaccination records.
  • Contact your health care provider. They may have a copy on file.
  • Check with the public health unit where you or your child attended school. For Region of Waterloo Public Health, you can look up records online.

Where to get vaccinated

Measles vaccines are available through your health care provider. Some walk-in clinics also give measles vaccines, but it is recommended you call ahead to find out before you go. 

Public Health can provide measles vaccines to people without a health care provider through our routine vaccine clinics.

Other vaccination options

How do I know where there is currently measles activity?

For measles activity in Canada, see the Government of Canada’s Measles and rubella weekly monitoring report. For international activity, see the Public Health Agency of Canada’s travel health notices.

Additional resources 

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