Important Measles Information
- Measles remains endemic in many parts of the world, and several high profile outbreaks are occurring in parts of North America.
- Immunization is the best way to protect against measles. Individuals travelling outside of North America, and to areas of known measles activity within North America, should ensure they are adequately protected prior to travelling.
- Clinicians should consider measles in patients presenting with fever and rash and other measles symptoms (cough, runny nose, conjunctivitis), among those with recent travel or who have had known contact with a case of measles.
Cases in Ontario (Epidemiological Summary)
As of November 14, 2019, a total of 14 laboratory-confirmed cases of measles have been reported in Ontario. The most recent case occurred on November 8, 2019 (date of rash onset). Twelve are index cases and two are secondary cases. All but one of the twelve index cases are associated with travel outside Canada.
In 2018 there were 8 confirmed cases of measles reported in Ontario. Over the last five years, the number of confirmed measles cases reported in the province has ranged from 7 in 2016 to 22 in 2014.
For more information on historical trends visit our Reportable Disease Trends in Ontario tool for measles.
All individuals, whether or not they are travelling, should ensure they are immunized according to the Publicly Funded Immunization Schedules for Ontario.
Individuals travelling outside of North America, and to areas within North America currently experiencing outbreaks, should ensure adequate protection against measles (unless they have a history of lab confirmed infection or laboratory evidence of immunity). Eligibility for publicly funded vaccine before travel is outlined in the Ontario schedules.
As per the Canadian Immunization Guide (CIG), the following is recommended prior to travel:
- Infants 6 to 11 months of age: one dose of MMR (two additional doses are required at ≥ 1 year of age)
- Individuals born in or after 1970: two doses of MMR
- Adults born before 1970: one dose of MMR
To ensure two doses of MMR before travel, children < 4 years of age who have received one dose (according to the routine schedule) should be considered for an early second dose of MMR.
Note: The minimum interval between doses of measles-containing vaccine is 28 days.
Advice regarding immunization for travelers should be personalized based on the individual’s health history and travel itinerary.
Unknown Immunization Status: Immunization vs. Serology
If a patient’s immunization records are unavailable, immunization with measles-containing vaccine is preferred, rather than ordering serology to determine immune status. This avoids the potential for false positive results, reduces the risk of missed opportunities for immunization and is consistent with advice from the CIG. Please note this does not apply to specific occupational groups such as healthcare workers who require either documentation of immunization or serologic proof of immunity.
PHO Grand Rounds: Measles and varicella maternal antibody waning in Ontario infants
In this presentation, we will outline the epidemiology of measles and varicella. We will also describe a study performed at the Hospital for Sick Children in Toronto to investigate immunity to measles and varicella in infants that are less than 12 months of age.