Mumps Virus Antibody, IgM
ARUP #99589, EPIC: LAB6109, SOFT: XMUMP
Acute and convalescent specimens must be labeled as such; parallel testing is preferred and convalescent specimens must be received within 30 days from receipt of the acute samples. Please mark sample plainly as "acute" or "convalescent".
Specimen Collection Criteria
Collect (preferred specimen): One Gold-top SST tube.
Also acceptable: One plain Red-top tube.
Physician Office/Drawsite Specimen Preparation
Let specimen clot 30-60 minutes then centrifuge to separate serum from cells within two hours of collection. Transfer serum to a plastic transport tube and refrigerate (2-8°C or 36-46°F).
Preparation for Courier Transport
Transport: 1.0 mL serum, refrigerated (2-8°C or 36-46°F). (Min: 0.2 mL)
- Hemolyzed specimens.
- Severely lipemic specimens.
- Specimens not collected and processed as indicated.
Specimen Stability for Testing:
Room Temperature (20-26°C or 68-78.8°F): 48 hours
Refrigerated (2-8°C or 36-46°F): 14 days
Frozen (-20°C/-4°F or below): 1 year
Specimen Storage in Department Prior to Disposal:
Specimen retention time is determined by the policy of the reference laboratory. Contact the Sendout Laboratory with any questions.
Sent to ARUP Laboratories, Salt Lake City, UT.
Monday - Friday.
Results available in 2-6 days.
Negative (0.79 IV or Less): No significant level of detectable IgM antibody to Mumps virus.
Equivocal (0.80-1.20 IV): Borderline levels of IgM antibody to Mumps virus. Repeat testing in 10-14 days maybe helpful.
Positive (1.21 IV or Greater): Presence of IgM antibody to Mumps virus detected, which may indicate a current or recent infection. However, low levels of IgM antibody may occasionally persist for more than 12 months post-infection or immunization.
Semi-Quantitative Enzyme-Linked Immunosorbent Assay.
Appearance of an IgM antibody response normally occurs 7-14 days after the onset of disease. Testing immediately post-exposure is of no value without a later convalescent specimen. While the presence of IgM antibodies suggest current or recent infection, low levels of IgM antibodies may occasionally persist for more than 12 months post-infection or immunization. Such a residual IgM response may be distinguished from early IgM response to infection by testing sera from patients 2-3 weeks later for changing levels of specific IgM antibodies.
The clinical diagnosis of an acute infection may be supported by the demonstration of virus-specific IgM. Assays for IgM are more useful than IgG assays, since cross-reactions have not been observed. Positive IgM mumps antibody suggests infection within the past 2-3 months. For paired sample results, an acute result less than 1:10 and convalescent greater than 1:10, or a four-fold rise in titer, suggests a primary infection with mumps virus unless the individual has recently acquired passive antibody.
Once transmitted, the mumps virus can produce symptomatic and asymptomatic infections. Typical mumps is an acute, self-limiting disease characterized by bilateral or unilateral parotitis. However, mumps virus infections can sometimes cause meningoencephalitis, orchitis, ovaritis, pancreatits, thyroiditis, or infections of the eye or inner ear. (1)
Mumps is endemic throughout the world. Prior to licensing of the live attenuated mumps vaccine, epidemics occurred every 2-5 years with the peak incidence occurring from January through May. In the prevaccine era, more than 50% of cases occurred in the 5-to 9-year group and 90% of disease occurred in children under 14 years of age. Today, more than 50% of mumps cases occur in teenagers and young adults. (1)
The incubation period is 16-18 days with a range of 2-4 weeks. Patients are infectious from 9 days prior, to 8 days after, the development of parotitis. Urine from mumps patients should be considered infectious for two weeks after onset of symptoms. (1)
Mumps is transmitted by direct contact and through inhalation of infectious aerosols. In addition, the virus can be spread indirectly by autoinoculation of the nose or mouth after handling infected fomites, soiled handkerchiefs, or tissues. (1)
- Wiedbrauk D, Johnston SLG. Manual of Clinical Virology, Raven Press, New York, NY, 1993.
ARUP #99589, EPIC: LAB6109, SOFT: XMUMP