Vaccine-Preventable Diseases Measles

Updated: June 1, 2011

Description and Symptoms

Measles is a highly contagious and acutely infectious disease caused by a virus. Symptoms include fever, cough, coryza (runny nose), conjunctivitis, Koplik spots (white spots on the inner lining of the mouth) and rash. Complications can include diarrhea, otitis media, bronchopneumonia, encephalitis and in rare cases, subacute sclerosing panencephalitis (SSPE). The virus is transmitted by airborne droplets (sneezing or coughing) or direct (close personal) contact with nasal or throat secretions of infected persons. Less commonly, the virus spreads through contact with articles freshly soiled with nasal and throat secretions.

Measles (rubeola) is a leading cause of vaccine-preventable deaths in children worldwide. There has been a marked reduction in incidence in countries where vaccine has been widely used, but measles remains a serious and common disease in many parts of the world. Complications such as otitis media and bronchopneumonia occur in about 10% of reported cases, even more commonly in those who are poorly nourished and chronically ill, and in infants under 1 year of age. Measles encephalitis occurs in approximately 1 of every 1,000 reported cases and may result in permanent brain damage. Measles infection causes subacute sclerosing panencephalitis (SSPE), a rare but fatal disease. In developed countries, including Canada, death is estimated to occur once in 3,000 cases. Measles during pregnancy results in a higher risk of premature labour, spontaneous abortion and low birth weight infants.

Prevention

The virus can be spread for about four days before and until about four days after rash onset. Health officials have implemented a public information campaign to advise patients, the general public and health care providers on the appropriate control measures. People experiencing measles symptoms are advised to call before going to a doctor's office or clinic as a precaution to assist health care providers in preventing further spread of the disease.

Measles is a vaccine-preventable disease. Canadians are reminded to keep all vaccinations up-to-date. Two doses of measles/mumps/rubella (MMR) vaccine are recommended for children. One dose administered on or after the first birthday; the second dose should be given after 15 months of age but before school entry. A second dose of MMR vaccine is also recommended for Canadians at greatest risk of exposure; for example, travellers to measles-endemic areas, healthcare workers, military recruits and students at post-secondary institutions. Speak to your health care provider regarding the status of your immunization and ensure that your vaccinations are up to date. 

Occurrence

During the XXIV Pan American Sanitary Conference in September 1994, representatives from Canada and other Pan American Health Organization nations resolved to eliminate measles in the World Health Organization region of the Americas. Shortly thereafter, in 1995, Canada's Conference of Federal/Provincial/Territorial Deputy Ministers of Health endorsed a national goal of measles elimination.

Nationally, sustained transmission has been eliminated by the current 2-dose measles immunization programs and high vaccine coverage in the general population. The 2004 National Immunization Coverage Survey (NICS) estimates that 94% of two year-olds have received one dose of measles vaccine and that 79% of seven year-olds have received at least two doses. Epidemiological and virological evidence suggests that endemic transmission of measles has been mostly interrupted since 1998; however, as expected, imported cases continue to occur. Secondary spread from these cases is usually self-limited and involves the few Canadians who are still vulnerable due to under-vaccination or opposition to immunization.

Canada has had a national measles surveillance system in place since 1998. All provinces and territories report confirmed cases of measles weekly to the Public Health Agency of Canada who in turn report weekly to the Pan American Health Organization.

Between 2002 and 2010, a total of 327 confirmed cases of measles were reported in Canada, with an average of 11 cases annually except in 2007 (102 cases), 2008 (62 cases) and 2010 (99 cases). The high numbers of cases in those three years were mainly due to outbreaks in Quebec, Ontario and British Columbia respectively.

Internationally, measles remains endemic in many countries and affects more than 1 million people annually. For information on areas where measles is endemic or where large outbreaks are occurring, please visit www.travelhealth.gc.ca.