Infectious diseases & vaccines Infectious diseases Measles


Measles is a highly contagious vaccine‐preventable infection caused by a virus.  The most common complication of measles is pneumonia, a bacterial infection of the lungs. Other complications include severe diarrhea, croup (condition resulting from blocked airways), otitis media (ear infection), and encephalitis (brain swelling). Although rare, a complication can occur several years later, causing brain damage or death. 

How do I know if I have measles?

Symptoms of measles include:

  • Fever, cough and runny nose
  • Red, irritated eyes and light sensitivity
  • Small bluish white spots called Koplik’s spots may also be seen inside the mouth and throat
  • The last symptom to appear is a red, blotchy rash (maculopapular) which first appears on the face then spreads down over the body

Symptoms can start anywhere from 7 to 18 days (but usually about ten days) after a person has been exposed to the virus (incubation period). The rash will begin to fade after about a week. On average, the illness lasts a total of 7‐14 days.

How is it spread?

Measles is an airborne virus that is transmitted in tiny droplets when an infected person coughs, sneezes, or breathes. It can survive for 2 hours on infected surfaces or in the air; therefore, it spreads quickly and easily. Measles is contagious 4 days before the rash appears (and one day before the first symptoms appear) until 4 days afterwards.

What do you do if you are exposed to measles?

If you have been exposed and are not immune (through vaccination or previous infection), a vaccine can prevent measles from developing if given within 72 hours of exposure. A blood test can determine your immune status if you do not know it. 

If you suspect you or your child has measles, contact a health care provider. Please call ahead and let your health care provider know you suspect measles so precautions can be taken in the office. 

Anyone in the infectious stage should stay away from day care, school and work for at least 4 days after the appearance of the rash.

What is the risk to pregnant women?

Pregnant women who catch measles have a greater risk of miscarriage, premature delivery, and low birth weight infants. For mothers who have already had measles, their newborn babies are protected for approximately six months by transfer of antibodies from the mother’s immune system.

How is measles treated?

There is no treatment for this viral illness. Supportive measures can be taken to relieve sore throat, cough and fever. 

Immunization prior to exposure is the best defence against infection.

How can measles be prevented?

Immunization. Two doses of measles vaccine are given to children after their first birthday to provide optimal protection. Measles vaccine is given in combination with other vaccines. MMR (measles, mumps, rubella) vaccine should be administered at 12 months of age and the second dose should be given as MMRV (measles, mumps, rubella, varicella) between four to six years of age preferably prior to school entry. 

Some adults may have received only one dose of the vaccine in the past. A second dose of MMR is recommended for young adults (18-25 years), post-secondary students, persons who received killed measles vaccine (1967-1970), health care workers or those who plan to travel internationally. Measles vaccine should not be given to pregnant women.

Can I get measles more than once?

No. Once someone has had measles they are protected for life.


Contact Oxford County Public Health & Emergency Services:
5519-421-9901 or 1-800-922-0096

Immunization Information
Additional resources/links

Public Health Agency of Canada
Government of Canada Travel Travel Health Notices
Caring for Kids - Information for parents from Canada's Paediatricians
Download the fact sheet as a PDF
Information for health care providers