Communicable Disease Control

Mumps Outbreak Investigation

Last updated on April 26, 2017 (Updates will occur on Wednesdays at noon.)


Toronto Public Health (TPH) is currently investigating a mumps outbreak in the city. As of noon on April 26, 2017, there are 76 confirmed cases of mumps in Toronto:


  • Most of the cases are among 18-35 year old individuals
  • Five of the cases are related to elementary and high schools in Toronto, either among staff or students


All of the cases related to Toronto school settings acquired the mumps from close contact with a known individual who already had the mumps and not from the school setting. However, broader community spread of the mumps is now occurring in Toronto. Individuals should ensure they are up-to-date with their vaccinations against the mumps.

Mumps infection and spread during outbreaks

The mumps virus is found in saliva and respiratory droplets. It is spread from person to person through coughing, sneezing, and coming into contact with a person's saliva by sharing drinks or utensils, food or water bottles, or by kissing. A major factor contributing to outbreaks is being in a crowded environment, such as attending the same class, playing on the same sports team or living in a dormitory with a person who has the mumps.

Toronto Public Health is asking the public to take the following general precautions:

1) Check vaccination records for you and your child

  • Two doses of mumps vaccine (MMR, MMRV) are recommended for all individuals born in 1970 or later.
  • Children receive one dose after the first birthday (MMR) and a second dose at 4 to 6 years of age as part of Ontario's Publicly Funded Immunization Schedule; check your child's yellow immunization card.
  • Individuals born between 1970 and 1992 may have received only one dose as a child. If an adult is unsure about their vaccinations or has only received one dose of mumps-containing vaccine, a booster dose is recommended.

2) Watch for symptoms of mumps

The mumps infection causes fever, swelling of one or more salivary glands, loss of appetite, tiredness, and headache. If you or your child have symptoms of the mumps and are ill, please contact your health care provider and do not attend work or school.

3) Planning to travel

Ensure that your immunizations are up-to-date for you and all your family members before travelling.


For more information see Toronto Public Health's mumps fact sheet and recent media release