What is measles?

Measles, also called rubeola or red measles, is an infection caused by a virus.  Once quite common, measles can now almost always be prevented with a vaccine.

Although Measles cases are quite rare, cases and outbreaks are on the rise across the globe, including certain countries in Europe and some parts of the United States (including Florida).

Vaccination provides the best protection against measles.

How is measles spread?

Measles virus is highly contagious.  The virus spreads easily through the air and can contaminate surfaces.    It can survive in the air and on surfaces for up to 2 hours, even after an infected person has left a room.  

People get exposed to the virus when they breathe in the air or touch contaminated surfaces.  Over 90% of people who are not immune and who come into contact with the virus will become infected.  

A person who is infected with measles also spreads the virus before they start having any symptoms and before they realize they have measles.   By the time someone with measles develops the measles rash, they have generally been contagious for 4 or 5 days. 

What are the signs and symptoms of measles?

Symptoms begin anywhere from 7 to 21 days after a person has been exposed to the virus.

Initial symptoms of measles include:

  • fever, cough, runny nose
  • drowsiness, irritability and red eyes

Small white spots can appear on the inside of the mouth and throat but are not always present; if they do appear, it’s usually 2 to 3 days after symptoms begin.

A red blotchy rash can appear on the face, and then progresses down the body approximately 3 to 7 days after symptoms begin and usually last 4 to 7 days.

Complications may include, diarrhea, pneumonia, blindness and swelling of the brain.  Measles can seriously affect those persons who are under-vaccinated and suffer from malnutrition, are immunocompromised or are pregnant.

What should I do if I am exposed to measles?

If you have been exposed and are not protected, a measles containing vaccine can prevent the infection from developing.  It is most effective if you receive this vaccine within 72 hours of exposure. However, receiving the measles vaccine any time after exposure will still help decrease the chance of becoming infected.

The following groups who are not protected by vaccination may be eligible to receive another medication for up to 6 days after exposure:

  • pregnant women who are not vaccine protected; 
  • individuals who have problems with their immune system; and
  • infants under 6 months of age 

The following individuals would be considered protected against measles:

  • anyone born before 1970
  • anyone who had measles in the past
  • anyone who has received two doses of vaccine

What should I do if I have symptoms of measles?

Individuals with symptoms should:

  • Isolate away from others.
  • Seek medical attention immediately. NOTE: Let the health care facility know that you may have measles before leaving your area of isolation  this will allow the facility to take appropriate precautions to prevent spread to others when you arrive.
  • Remain isolated and do not return to school/child care, work, sporting events, health care facilities and other group settings until 4 days after the appearance of the rash if you or someone in your house has been diagnosed with measles by a health care provider.
  • Follow the directions provided by the Thunder Bay District Health Unit’s (TBDHU) Infectious Diseases team as TBDHU will be informed if you are diagnosed with measles.

How can measles be prevented?

Vaccination is the best protection against measles. Measles vaccinations provide protection against measles, mumps, rubella (MMR vaccine) or measles, mumps, rubella, varicella (MMRV vaccine).

All individuals, whether or not they are travelling, should make sure they are immunized according to the Publicly Funded Immunization Schedules for Ontario.

  • Infants 6-11 months of age travelling somewhere where measles is present can get one dose of the vaccine before they travel. Two additional doses are still needed after their first birthday to complete their routine series.
  • Children routinely receive their first dose of vaccine on or after their first birthday and a second dose between the ages of 4-6.
    • Children can get the second dose as soon as they turn 4 which is strongly recommended for those with plans to travel outside of Canada.
  • Adults 18 years of age and older born in or after 1970 should have received at least one dose of vaccine. Two doses are recommended if a health care worker, attending post-secondary education, such as college or university, or are travelling outside Canada.
  • Adults born before 1970 are generally considered immune as they likely came into contact with the measles virus when they were younger. 
    • Travellers to areas where measles is present or students in post-secondary educational settings, such as college or university, who have never had a measles infection should check their vaccine record to confirm they have had one dose.
  • Health care workers and military personnel are recommended to have:
    • two doses of vaccine (regardless of their age); OR
    • proof of immunity against measles (i.e. lab confirmed immunity).
  • Infants under 6 months of age, pregnant people and those with a weakened immune systems are generally not recommended to receive the vaccine.

Those who are unsure about immunity can check their vaccine records or speak with a health care provider.

Immunization records are available from the Health Unit. Please visit Reporting and Obtaining Immunization Records | Thunder Bay District Health Unit ( to learn more.



Measles activity has been increasing worldwide. Before traveling outside of Canada, make sure your family’s vaccines are up to date. Please see the Government of Canada's measles travel health notice for more information and vaccine recommendations.

To check your or your child’s measles vaccine status:

  1. Contact the health care provider or clinic where you or your child received vaccines.
  2. Vaccine records for school-aged children can also be accessed through Immunization Connect Ontario (ICON), if you had previously set up an account.

If you or your child need to be vaccinated against measles:

  1. Book an appointment with your health care provider.
  2. If you do not have a health care provider or are unable to access vaccination before your departure date, contact the Health Unit at 807-625-5900 (press 1) or call your local branch office to learn more about the Health Unit’s vaccine clinics.
  3. If you or your child require other travel vaccines or medications prior to travelling, please contact the Janzen’s Pharmacy travel clinic (fees may apply) in Thunder Bay.

For Further Information

Call the Infectious Disease Program at (807) 625-8318 or toll-free at 1-888-294-6630 for questions about measles. Call the Vaccine Preventable Diseases Program at (807) 625-5900 or toll-free at 1-888-294-6630 for questions about measles vaccination.

Health Topic
Diseases & Infections