Mumps
Reporting Obligations
Individuals who have or may have mumps shall be reported to the local Health Unit.
Epidemiology
Aetiologic Agent
Mumps is caused by an RNA virus of the genus Rubulavirus in the Paramyxoviridae family.
Clinical Presentation
Fever, swelling and tenderness of one or more salivary glands. Parotitis will develop in about 40% of those infected. Approximately 20–30% of infections are subclinical, but remain communicable. Respiratory symptoms of 50% of those who acquire infection can add to the difficulty in diagnosing mumps. Orchitis is a common complication after puberty. Permanent sequelae such as infertility and hearing loss are rare. Mumps infection during the first trimester of pregnancy may increase the rate of spontaneous abortion.
Modes of Transmission
Droplet spread during face-to-face contact and direct contact with saliva or respiratory droplets from the nose or throat of an infected person. Mumps is spread through coughing, sneezing, sharing drinks, kissing, or from contact with any surface that has been contaminated with droplets containing the mumps virus.
Incubation Period
Ranges from 12–25 days, commonly between 16–18 days.
Period of Communicability
A person with mumps is able to spread infection from 7 days before to 5 days after the onset of parotitis.
Risk Factors/Susceptibility
Attends post-secondary institution.
Not immunized or partially immunized.
Immunocompromised.
After natural infection, immunity is generally lifelong. Effectiveness of mumps vaccination after one dose is between 62–91% and between 76–95% after two doses. There is evidence to suggest waning immunity after both one and two doses of vaccine.
Diagnosis and Laboratory Testing
A buccal swab, throat swab and urine are the recommended clinical samples for RT-PCR testing. In order to increase the overall sensitivity of testing, all three specimens should be submitted, as not all sites are positive at the same time.
Optimal recovery of mumps virus is achieved if specimens are obtained 3–5 days after symptom onset.
Treatment and Case Management
All clinical cases should be managed as confirmed cases until lab evidence suggests otherwise.
Cases should be advised to stay home from school or post-secondary educational institutions, child care facilities, workplaces, and other group settings for 5 days from symptom onset. Self-isolation will prevent exposure of susceptible individuals to the virus.
For hospitalized cases, droplet precautions is recommended until 5 days after onset of symptoms.
Contacts will be identified and followed by Public Health staff.
Susceptible contacts include:
- Those born in Canada in 1970 or later who have not received two doses of mumps- containing vaccine (at least 4 weeks apart) on or after their first birthday;
- Those without past history of laboratory confirmed mumps; and
- Those without documented immunity to mumps.
Note: While persons who have received two doses of mumps containing vaccine are not considered “susceptible contacts”, there may be secondary cases in this group as a result of waning immunity, especially if they have been vaccinated greater than ten to 12 years prior to exposure.
Post-exposure prophylaxis with mumps immune globulin (Ig) is ineffective. Contacts should be advised of signs and symptoms of mumps infection that can occur within 25 days of exposure and to seek medical attention upon symptom onset if required. Immunization of mumps-susceptible contacts with MMR vaccine should be considered.
Patient Information
Additional Resources
Publically Funded Immunization Schedule for Ontario, January 2021.
Ontario Health Association. “Mumps Surveillance Protocol for Ontario Hospitals.”
Public Health Agency of Canada. “Canadian Immunization Guide, 7th ed., Mumps Vaccine.”
References
Ministry of Health and Long-Term Care, Infectious Diseases Protocol, 2022.