Mumps Virus

The information provided is offered as a resource for Wisconsin Laboratories and Health Care Facilities.

  • All suspected cases of mumps should be immediately reported to the local public health department.


  • Note that mumps testing at the Wisconsin State Laboratory of Hygiene (WSLH) and the cost of specimen transport will be performed on a “fee for service” basis, unless fee-exempt testing and transport are approved by the local health department or the Wisconsin Division of Public Health. 
  • Specimens for Testing

    • Specimens to be collected in most cases are:
      • Acute serum
      • Buccal swab
      • Urine specimen
      • CSF specimen if central nervous system disease is present
      • Specimen collection and transport instructions can be found below.  
  • In accordance with CDC guidelines, the Wisconsin State Laboratory of Hygiene (WSLH) recommends collection of specimens for serology and culture and real-time polymerase chain reaction (PCR) testing for all suspect cases of mumps. Specimens for culture and PCR testing should be collected at the same time as the acute serum for mumps IgM serology.

    • Clinical specimens for viral isolation are extremely important for molecular epidemiologic surveillance to help determine the geographic origin of the virus and the viral strains circulating in the United States.

  • Mumps PCR (polymerase chain reaction) of buccal swabs is the preferred test for mumps at the WSLH. 


  • An acute-phase serum for mumps IgM antibody should be collected as soon as possible after the onset of symptoms and a second (convalescent-phase) serum should be collected 2-3 weeks after the first serum.  


  • In cases of central nervous system disease (aseptic meningitis), collect and submit a CSF specimen without dilution or additives.
  • Specimen Collection Instructions

    • Buccal Swabs (Buccal swabs are the preferred specimen for PCR testing for mumps.)

      • Collect buccal swab specimen as soon as mumps is suspected and within 9 days of onset for the best chance of detection of virus. 

        • Massage the parotid gland area for 30 seconds, then swab the area around Stensen’s duct.   

          • Flocked synthetic swabs appear to be more absorbent and elute samples more efficiently. Do not use cotton or calcium alginate swabs as they may be inhibitory to enzymes used in PCR.  A commercial product designed for the collection of throat specimens or a flocked polyester fiber swab can be used.

          • For specific instructions and illustrations of specimen collection, go to http://www.cdc.gov/mumps/lab/detection-mumps.html


      • Place the swab in a vial of virus transport medium; any commercially available virus transport medium is acceptable. 


      • Maintain specimen at refrigerator temperature prior to transport. Transport at refrigerator temperatures using kool-packs. 


    • Urine Samples (Urine specimens are not as useful as buccal swabs for detection of mumps and may not be positive until more than 4 days after onset.)  

      • Collect urine (preferably at least 50 ml, per CDC) in an empty container; do not add virus transport medium.


      • Maintain the urine specimen at refrigerator temperature prior to transport. Transport at refrigerator temperatures using kool-packs. 


    • Serum Samples 

      • Collect the first (acute-phase) serum as soon as mumps disease is suspected.  Collect 7-10 ml of blood in a red top or serum separator tube (SST).  


      • A second serum for repeat IgM testing (collected 5-7 days after onset of parotitis) may be useful if the first serum is negative for IgM antibody to mumps and was collected within 3 days of parotitis onset in an unvaccinated person.


      • A second (convalescent-phase) serum specimen should be collected 2-3 weeks after the first serum. 


      • Store specimens at refrigerator temperature. Transport at refrigerator temperatures using kool-packs. 


      • Paired sera can be of value for patients with no history of vaccination. Collect acute serum as soon after onset as possible and collect the convalescent serum 2-3 weeks later to determine if a significant change in IgG antibody titer has occurred. 


      • A 4-fold rise in IgG titer is rarely demonstrated between paired serum samples from persons who have received one or two doses of MMR vaccine.


  • Specimen Submission Instructions

    • When submitting specimens to the WSLH for mumps testing, include a completed requisition form (CDD form A or B). If you do not have a WSLH requisition form available, you may substitute the "General Outbreak" form available at General Outbreak Response Form (Word DOC).  


    • Be sure to complete the submitter information, along with complete patient information, and the agent and test requested. 


  • Specimen Transport Instructions

    • All specimens should be transported to the WSLH as soon as possible at refrigerator temperatures using kool-packs. 


    • Transport arrangements and costs are the responsibility of the submitter unless other arrangements are agreed to by the WSLH.  


  • Testing at the WSLH

    • PCR Testing:  The WSLH will perform mumps PCR testing of buccal swabs and urine specimens within 48 hours of specimen receipt.  

      • The WSLH may perform culture and/or PCR for other agents that can cause similar symptoms; non-requested testing will be performed at no cost to the submitter. 


      • Aliquots of swab and/or urine specimens will be forwarded to CDC for culture and characterization as appropriate. 


    • Mumps IgM Serology Testing: The WSLH does not perform mumps IgM serology testing of acute serum.  Aliquots of serum specimens will be forwarded to CDC for additional testing as appropriate.  


    • Mumps IgG Serology Testing:  The WSLH can perform mumps IgG serology testing on a single serum to assess an individual’s immune status for mumps.  IgG serology testing of a single serum is NOT used for diagnosis of an acute case.  


      • Mumps IgG serology of paired sera is not recommended for previously vaccinated individuals. 


      • The test can be of value for patients with no history of vaccination or with seronegative acute specimens. Collect acute (as soon after onset as possible) and convalescent (from two to three weeks after onset) sera to determine if a significant change in IgG antibody titer has occurred (e.g., from 1:40 to 1:320). 


      • Diagnostic testing of paired sera for IgG antibody to mumps is available at the WSLH on a fee-for-service basis. 


    • Mumps Culture Testing:  Isolation of mumps virus is not recommended as a routine method to diagnose mumps, but virus isolates are extremely important for molecular epidemiologic surveillance to help determine the geographic origin of the virus and the viral strains circulating in the United States. 

      • The WSLH will forward aliquots of appropriate specimens to the CDC for mumps culture. 


  • WSLH Test Results

    • Negative results do not rule out mumps infection due to the following:

      • The amount of virus shed at the time of sample collection may have been too low to be detected. 


      • Inadequate specimen collection, processing, shipping or storage can significantly reduce the likelihood of detecting mumps virus or mumps RNA.


      • Mumps IgM antibody may be transient or undetectable in previously vaccinated individuals. 


      • The full clinical and epidemiologic picture should be taken into consideration when interpreting test results.  


    • Mumps IgM Serology Results

      Mumps IgM:    Negative
      This result indicates that no IgM antibody to mumps virus was detected.  The absence of mumps-specific IgM antibody may indicate that this patient is not currently infected with mumps, but IgM antibody may be absent or transient in persons who were previously immunized.  A negative result does NOT rule out recent or current infection with mumps virus.

      Mumps IgM:  Positive
      This result indicates that IgM antibody to mumps virus was detected.  The presence of mumps-specific IgM antibody usually indicate that this patient was recently infected or recently immunized with mumps virus.

      Mumps IgM:  Equivocal
      This result indicates that the testing performed cannot definitively determine whether a significant level of IgM antibody to mumps virus was or was not detected. 


    • Mumps Virus PCR Test Results

      Mumps Virus PCR:  Indeterminate
      This result indicates that this specimen was suboptimal or exhibited inhibition in the PCR assay, so an accurate result could not be obtained. If clinically warranted, repeat testing is suggested.

      Mumps Virus PCR:  Equivocal
      This initial result indicated a low level of mumps virus RNA, but repeat testing failed to confirm the initial result.

      Mumps Virus PCR:  Mumps virus RNA detected.
      This result indicates that testing has detected mumps virus genetic material in the specimen; this specimen is considered positive for mumps.

      Mumps Virus PCR:  No Mumps virus RNA detected.
      This result indicates that testing was not able to detect mumps virus genetic material in the specimen.  A negative result, however, does not rule out infection with mumps virus, as many factors in the collection and transport of the specimen could significantly reduce the likelihood of detecting mumps virus RNA.

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