Mumps – Serology

Testing Indications

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

When Mumps infection is suspected - Contact your local Public Health Ontario Laboratory to ensure that appropriate testing is requested and inform your local Public Health Unit of all probable or suspect cases of mumps.

Diagnostic requests for symptomatic patients or post exposure, refer to the test information sheets Mumps-Diagnostic PCR 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

Whole blood or serum

5.0 ml whole blood or 1.0 ml serum

Blood, clotted - vacutainer tubes (SST)

Mumps Diagnosis

Whole blood or serum

5.0 ml whole blood or 1.0 ml serum

Blood, clotted - vacutainer tubes (SST) 

Submission and Collection Notes

1

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

2

Mumps IgG and IgM testing will be performed on diagnostic requests only when the following clinical information is provided on the General Test Requisition Form indicating acute/recent infection, vaccination history, relevant signs, symptoms, and/or clinical history, and onset date.

Timing of Specimen Collection

Acute: Collect the acute sample within 7 days after the onset of symptoms.

Convalescent: Collect the convalescent sample 7 to 10 days after the acute.

Limitations

Hemolysed, icteric, lipemic or microbially contaminated sera or plasma are not recommended for testing.

Preparation Prior to Transport

Label the specimen container with the patient’s full name, date of collection and one other unique identifier such as the patient’s date of birth or Health Card Number. Failure to provide this information may result in rejection or testing delay.

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 by PHO Laboratory.

Reporting

Mumps IgG is a qualititative test. Mumps IgG test results are reported qualitatively (Non-Reactive, Indeterminate or Reactive) together with an interpretation of the patient’s immune status based on the level of Mumps IgG detected.

Mumps IgG and IgM diagnosis serology is performed when requested along with clinical information indicating acute/recent infection, vaccination history, relevant signs, symptoms, and/or clinical history, and onset date. 

Results are reported to the ordering physician or health care provider as indicated on the requisition.

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.

 

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 to Mumps virus in human serum samples.

The Mumps IgM test is  performed using the chemiluminescence immunoassay (CLIA) technology for the qualitative determination of specific IgM antibodies to Mumps virus in human serum samples. It is intended to be used as an aid in the determination of serological status to mumps virus.

The test is  performed on the LIAISON® XL Analyzer platform.

Interpretation

After a primary infection, both IgM and IgG antibodies develop within 3-7 days after onset of mumps specific symptoms. Both antibodies subsequently increase reaching a plateau 2-3 weeks later.

Antibody levels may be reported as Non-Reactive (no detectable antibody), Indeterminate (the level of antibody detected is considered borderline reactive or equivocal) or Reactive (antibody is detectable within the positive range of the assay).

Non-Reactive and Indeterminate levels of both IgM and IgG 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 occasionally due to assay non-specificity.

If the acute blood sample shows indeterminate or non reactive IgG result and/or IgM result, a convalescent sample should be collected. Recent infection is confirmed if a significant rise in antibody levels is observed between acute and convalescent sera.

For more information concerning the interpretation of diagnostic IgM and IgG serology refer to the document titled: LAB-SD-044, Diagnostic Interpretation of Viral Specific IgM and IgG Serology.

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Updated 7 Oct 2020