Mumps – Serology

Consistent with O. Reg. 671/92 of the French Language Services Act, laboratory testing information on this page is only available in English because it is scientific or technical in nature and is for use only by qualified health care providers and not by members of the public.

This page provides serological testing information for Mumps at Public Health Ontario (PHO). For information regarding other testing options, refer to the following PHO web pages:

Mumps – Diagnostic - PCR

*Uncontrolled print copy. Valid only on day of print: 21 Nov 2024.

Testing Indications

Serology for Mumps Immunity (Mumps IgG) may be indicated to determine immune status either following natural infection or post-vaccination.

Unknown Immunization Status: Immunization vs. Serology
If a patient’s immunization records are unavailable, immunization with Mumps-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 Canadian Immunization Guide (CIG). This does not apply to specific occupational groups, such as healthcare workers, who require either documentation of immunization or serologic proof of immunity regardless of their birth year.

When Mumps infection is suspected – contact your local public health unit (PHU) prior to collecting specimens. Refer to STAT and Critical Specimens Testing section for instructions on sending priority specimens to PHO’s laboratory.

Diagnosis of symptomatic patients requires additional samples for testing by PCR. Refer to the Mumps-Diagnostic PCR test information sheet, for specimen collection and testing information.

Specimen Collection and Handling

Specimen Requirements

Test Requested	Required Requisition(s)	Specimen Type	Minimum Volume	Collection Kit
Mumps Immunity	General Test Requisition	Whole blood or serum	5.0 ml whole blood or 1.0 ml serum	Blood, clotted – serum separator tube (SST)
Mumps Diagnosis	General Test Requisition	Whole blood or serum	5.0 ml whole blood or 1.0 ml serum	Blood, clotted – serum separator tube (SST)

Submission and Collection Notes

Complete all fields of the requisition form, including:

Test(s) requests and indications for testing
Patient setting
Specimen type and source
Outbreak or investigation number
Clinical information (acute/recent infection, vaccination history, relevant signs, symptoms, and/or clinical history, and onset date).

Label the specimen container(s) with the patient’s first and last name, date of collection, and one other unique identifier such as the patient’s date of birth or Health Card Number. For additional information see: Criteria for Acceptance of Patient Specimens. Failure to provide this information may result in rejection or testing delay. Refer to Serology Testing – Laboratory Specimen Collection and Submission Instructions for more information.

Mumps IgG testing will be performed on all requests for Mumps immunity serology.

Mumps IgG and IgM testing will be performed on diagnostic requests only when clinical information is provided on the General Test Requisition Form.

Timing of Specimen Collection

Acute Specimen: Collect the acute sample within 7 days of symptom onset (e.g. parotitis, fever, etc.). Of note, specimens collected more than 3 days post-parotitis onset are more likely to have a positive IgM result than those collected earlier.
Convalescent Specimen: Collect the convalescent sample a minimum of 7 and up to 30 days after the acute sample collection. Collection after 10 days from the acute is preferred to improve the chances of observing a change in the antibody levels.

Limitations

Hemolysed, icteric, Lipemic or microbially contaminated serum is not recommended for testing.

Storage and Transport

Specimens should be stored at 2-8°C following collection and shipped to PHO’s laboratory on ice packs. Centrifuge if using serum separator tubes (SST). Place the specimen in a biohazard bag and seal.

All clinical specimens must be shipped in accordance with the Transportation of Dangerous Good Act.

Special Instructions

Centrifuge if using SST. Place specimen in biohazard bag and seal. Specimens should be stored at 2-8°C following collection and shipped to PHO Laboratory on ice packs.

Requisitions and Kit Ordering

Test Frequency and Turnaround Time (TAT)

Mumps serology to detect Mumps IgG and IgM is performed daily Monday to Friday.

Turnaround time is up to 5 days from receipt at PHO’s Laboratory.

Stat and Critical Specimens Testing

STAT testing is not available.

Priority testing is available for mumps diagnosis of symptomatic patients or persons who have been exposed to a confirmed case. Priority specimens must be packaged separately from routine specimens using TDG-compliant packaging and labelling. To assist with laboratory workflow and identifying priority specimens, mark STAT on the outside of the package. Contact customer service at 416-235-6556 or 1-877-604-4567 prior to specimen transfer to provide PHO’s laboratory with the expected arrival time.

Test Methods

The Mumps IgG test is performed using the BioPlex 2200 MMRV IgG kit for use with the Bio-Rad Bioplex 2200 System. It is a Multiplex Flow Immunoassay test intended for the qualitative detection of IgG antibodies against Mumps in human serum.

The Mumps IgM test is performed using chemiluminescence immunoassay (CLIA) technology for the qualitative determination of specific IgM antibodies to Mumps virus in human serum. The test is performed on Diasorin’s Liaison® XL Analyzer platform.

Interpretation

Following a primary infection, both IgG and IgM antibodies develop within 3 to 7 days after symptom onset. Both antibodies then increase reaching a plateau 2 to 3 weeks later.

Antibody levels may be reported as:

Non-reactive - no detectable antibody
Indeterminate - level of antibody detected is considered borderline reactive or equivocal
Reactive - antibody is detectable within the positive range of the assay

Non-Reactive and Indeterminate levels of both IgG and IgM antibodies may be observed in the acute stage of infection, rising to reactive levels in subsequent weeks. In the absence of acute infection, indeterminate levels of IgG may represent very low levels of antibody many years after initial infection or vaccination, whereas indeterminate levels of IgM may be due to declining levels of IgM several months post-infection or possibly due to assay non-specificity.

If the acute blood sample shows reactive, indeterminate or non-reactive IgG and/or IgM results then a convalescent sample should be collected. Recent infection is confirmed if a significant rise (greater than 2-fold) in antibody levels is observed between acute and convalescent sera.

Reporting

Results are reported to the physician, authorized health care provider (General O. Reg 45/22, s.18) or submitter as indicated on the requisition.

Mumps IgG test results are reported qualitatively together with an interpretation of the patient’s immune status based on the level of Mumps IgG detected.

Specimens that are positive (reactive) for Mumps IgM are also reported to the appropriate Medical Officer of Health as per Health Protection and Promotion Act.