Enhanced Surveillance for Mumps

Advisory Alert

May 19, 2017

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Dear Colleagues,

I am writing to advise you of a case of mumps occurring in southwestern Ontario with two contacts that have been identified from the Sudbury & District Health Unit catchment area. Please have mumps on your differential when patients present to you with symptoms as outlined in this alert.
The Advisory Alert provides you with a brief summary of the context of the exposure and information on mumps etiology, clinical presentation and transmission, laboratory testing, vaccine considerations and reporting.

Exposure Context

On May 18 the Sudbury & District Health Unit was notified of an exposure of two local youth to a lab-confirmed case of mumps while in attendance at a southwestern Ontario youth camp. The case’s mumps exposure occurred in Manitoba where there is an ongoing mumps outbreak. Onset of symptoms was May 10, 2017. The period of exposure to this case was from May 6 to 12, 2017. As you are aware, there has been an increase of mumps activity this year in Ontario and other provinces with most cases reported in the 18 to 35 year age groups.

Etiology, Clinical Presentation, and Transmission

Mumps is an acute viral disease usually characterized by fever, swelling, and tenderness of one or more salivary glands. Subclinical infection is common. Mumps is spread by contact with infected respiratory tract secretions. The incubation period ranges from 16 to 18 days, but cases may occur 12 to 25 days after exposure. Maximum infectiousness occurs between two days before to five days after onset of parotid swelling. Almost half (40%) of those infected with mumps develop parotitis on either one or both sides of the face. Some people with mumps have only respiratory symptoms and may not know they have the infection.

Persons with mumps should be advised not to attend childcare, school, work or other public places while infectious (until nine days after the onset of symptoms); and to avoid contact with children less than one year of age, or others who are not immune to mumps through vaccination or past infection, especially pregnant women, and individuals with a weakened immune system.

Laboratory Testing

fever. Specimens for both virus isolation and serologic testing should be obtained to confirm mumps infection. It is recommended to obtain specimens early in the course of illness when the number of viral copies is highest. Ensure that the lab requisition indicates that you are requesting mumps testing. Mark the symptoms, dates of onset of parotitis, exposure/travel history and vaccination history on the requisition.

a) Acute serology – A blood specimen, to test for mumps antibodies (IgM and IgG), should be obtained within seven days after the onset of symptoms.

b) Virus isolation by culture and RT-PCR testing – Obtain a buccal/throat swab and a urine sample (5 mL submitted in a sterile container) up to nine days after symptom onset. A buccal swab may provide the best viral sample. To collect the buccal sample, massage the parotid glad area for 30 seconds prior to collection. The parotid duct drains in the space near the upper rear molars, place the swab into that space for collection.

Follow-up Lab Testing

If the acute blood sample shows low reactive, indeterminate or non-reactive IgG result and/or IgM result, a convalescent sample should be collected.

a) Convalescent Serology – Drawn 7 to 10 days or more after symptom onset to check for a significant rise in mumps specific IgG antibodies between acute and convalescent sera seroconversion or a significant rise in IgG titre is indicative of recent infection.

Refer to the Public Health Ontario Laboratory Services webpage for further information on testing. http://www.publichealthontario.ca/en/ServicesAndTools/LaboratoryServices/Pages/default.aspx

Vaccination Considerations

Two doses of mumps containing vaccine is recommended for routine immunization of children and for immunization of children and adolescents who missed mumps immunization on the routine schedule. Susceptible adults born in or after 1970 generally require one dose of vaccine, although two doses are required for persons who are at greatest risk of infection (health care workers of all ages, travellers to destinations outside of North America, students in post-secondary educational settings).

Although mumps immunization (with the MMR vaccine) after exposure may not prevent the disease or alter clinical severity of infection, it should be given to susceptible persons who are without contraindications as exposure may not result in infection and vaccination will induce protection against subsequent exposures.


Mumps is a reportable disease in Ontario. Report any suspected mumps cases immediately to the Sudbury & District Health Unit for follow-up.

For all reporting, inquiries or comments, please contact:
Sudbury & District Health Unit at 705.522.9200, ext. 301.

This item was last modified on May 19, 2017