Measles, also called red measles or rubeola, is a very contagious viral infection. Measles spreads when a person infected with measles virus breathes, coughs, or sneezes. The virus can still be on surfaces and in the air up to 2 hours after that person is gone from a room. Measles still spreads in some parts of the world. Measles is rare in Canada due to high vaccination rates, but outbreaks do occur from time to time.
Symptoms of measles
Measles symptoms begin with a fever, runny nose, cough and red eyes. After a few days, a red blotchy rash will appear on the face and spreads down the body. Most people recover fully from measles in 2 weeks. Symptoms are more severe in infants and adults.
Measles can also lead to ear infections, lung infections (pneumonia), swelling of the brain (encephalitis), hearing loss, seizures, permanent brain damage (subacute sclerosing panencephalitis) or death. Measles in pregnancy can lead to premature delivery, low birth weight and miscarriage.
Timeline for infection
Symptoms usually appear 10 days (range 7 to 21 days) after contact with a person who is contagious with measles. The rash usually appears 10-14 days after exposure. An infected person can spread measles to others from four days before to four days after the rash appears. Once a person has had measles they are protected for life. If you think you have measles, it is important to speak to a doctor before visiting the doctor’s office so that the infection is not passed to others.
Persons at risk
- Infants are at greatest risk since routine vaccination for measles does not begin until one-year of age.
- Health care workers, travellers to areas where measles is circulating, post-secondary students and military personnel, are at greatest risk of measles exposure from unvaccinated/under vaccinated individuals and should ensure they are protected.
- Regardless of age, health care workers and military personnel are required to have two-doses of measles vaccine, or laboratory evidence of immunity, or a history of laboratory-confirmed measles disease.
- Those born before 1970 are likely immune to measles because measles was widely circulating in Canada then. Those who are unsure or at higher risk should get vaccinated with at least one dose of MMR vaccine. A blood test can also be done to find out if someone is immune.
- Those born on or after 1970 and have never had measles infection require vaccination for protection. Two doses of measles vaccine provide over 95% protection.
Diagnosis and treatment
Measles is diagnosed by the symptoms and laboratory tests including a blood, urine and throat test. There is no specific treatment for measles. Most people can recover at home. Supportive care in hospital may be needed for severe infections. Vaccination is the best protection.
Measles vaccine is available as measles-mumps-rubella (MMR) or measles-mumps-rubella-varicella (MMRV) vaccine. Both vaccines are made up of weakened, live viruses. One dose provides protection in about 85% of people, and two doses provide over 95%.
Recommendations for vaccination
- MMR vaccine is part of routine childhood immunization at age one and a second dose of MMRV vaccine (with chickenpox) is given at four to six years of age.
- MMR vaccine is safe for women who are breastfeeding.
- All persons born in 1970 or later should receive 2 doses of measles-containing vaccine.
- Susceptible health care workers, travellers, post-secondary students and military personnel should ensure they are protected. See "Persons at risk" for more details.
- If travelling to areas where measles is circulating widely, infants 6 to 12 months of age can receive one dose of MMR vaccine. Two additional doses of measles containing vaccine are required on or after the first birthday.
- Persons who are not immune and have been exposed to someone who is contagious with measles can receive the vaccine within 72 hours of exposure to prevent infection.
- Human immune globulin (Ig) may be used for measles post-exposure immunization in non-immune persons who are at high risk if given within 6 days of exposure.
Vaccine side effects and risks
Reactions to MMR and MMRV vaccine are generally mild and temporary and include pain and redness at the injection site, fever and rash. Risk of allergic reactions following immunization such as trouble breathing, rash, swelling in the throat and face may occur but are very rare and can be treated. For more information, see MMR vaccine fact sheet.
People who should not get the vaccine
- Individuals who have had a severe allergy to a previous dose of MMR, or any component of the vaccine, including gelatin or an antibiotic called neomycin sulphate
- Pregnant women
- Individuals with a severe weakened immune system (e.g., due to HIV, cancer or taking medications that weaken the immune system)
Delay MMR vaccine:
- If there is high fever or a infection more severe than a cold
- If you are pregnant, think you may be pregnant, or are trying to become pregnant
- Women should not get pregnant for one month after receiving the MMR vaccine
- Have recently received a blood product (e.g. serum immune globulin)
- Have recently received a live vaccine (e.g. MMR, chickenpox) in the past 28 days, or MMRV vaccine in the past 6 weeks.
Canadian Immunization Guide, Evergreen Edition. Part 4 Active Vaccines: Measles. Ottawa: Public Health Agency of Canada.