Lab Testing for Mumps at the MDH Public Health Laboratory

Though mumps is no longer common in the United States, outbreaks continue to occur as a result of internationally imported or import-linked cases. Continued success in disease reduction is dependent on maintaining awareness of the disease along with improving vaccination rates.  

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On this page:
Report suspect mumps cases
Clinical features and differential diagnoses

Lab tests offered at MDH-PHL
Timing of specimen collection for PCR
Preferred specimens: PCR
Specimen collection: PCR
Approved swabs and media
Transporting specimens to MDH

Report suspect mumps cases

If you suspect mumps in a patient:

  • Call MDH at 651-201-5414 or toll-free at 1-877-676-5414
  • Provide clinical details
  • Collect specimens for PCR testing

Hospitals and clinics are required by law to report suspect cases of mumps within one working day to MDH. However, calling while the patient is still in the office ensures timely reporting and guarantees that the correct specimen is collected and sent.

Clinical features and differential diagnoses

Mumps is characterized by:

  • Non-specific prodrome including myalgia, anorexia, malaise, headache, and low-grade fever
  • Acute onset of unilateral or bilateral tender swelling of the parotid or salivary gland lasting 2 or more days without other apparent cause

Mumps should be considered in the differential diagnosis of patients presenting with parotitis or swelling of the salivary glands, regardless of vaccination history.                                                                                

MDH also encourages health care providers to consider other infectious and non-infectious causes of parotitis. Other etiologies include:

  • Influenza A, Parainfluenza virus types 1 and 3, Epstein Barr virus, Coxsackie A virus, Cytomegalovirus, Herpes Simplex Virus, Lymphocytic choriomeningitis virus, HIV
  • Acute bacterial suppurative parotitis (Staphylococcus aureus and Streptococcus spp.)
  • Recurrent parotitis
  • Drug reactions, allergies, tumors, immunologic diseases

Lab tests offered at MDH Public Health Laboratory

Mumps Real-Time Polymerase Chain Reaction (RT-PCR, or PCR) is available for mumps case confirmation at the MDH Public Health Laboratory (MDH-PHL). Providers are asked to collect and send PCR specimens to MDH-PHL when mumps is suspected.

Providers may also order serologic testing through their normal reference laboratory. However, serologic test results must be interpreted with caution because false positive results are common. Mumps IgM results may be falsely positive due to cross-reactivity with other viruses and agents, including Parainfluenza viruses, Epstein-Barr virus, adenovirus, human herpes virus 6 (includes roseola), and S. pyogenes/group A (strep throat).

Timing of specimen collection for PCR

Clinical specimens for PCR should be taken as soon as mumps is suspected. Early specimen collection is particularly important for previously vaccinated individuals because they shed virus for a shorter period and in smaller amounts.

Ideally, specimens for mumps PCR should be obtained within five days of parotitis onset (0-9 days at most). Consider parotitis (or other symptom) onset date as day ‘0.’ If specimen collection occurs on days 0-2, it is especially important to consider and test for other differentials that cause parotitis.

Preferred specimens: PCR

Please send specimens to the MDH-PHL. The type and number of specimens sent varies for each case based on when swelling began.

  • On day 0-5 of swelling, collect a buccal swab*
  • On day 6-9 of swelling, collect a buccal swab and a urine specimen**

*If a buccal swab cannot be collected, a throat swab can be sent instead; however, a buccal swab is the preferred specimen for mumps PCR testing.
**If date of specimen collection is already more than nine days past swelling onset, PCR is less likely to detect viral presence and may give false negative results.

Failure to detect mumps viral RNA by PCR in samples from a person with no other compelling differential diagnoses may not always rule-out mumps.

Specimen collection: PCR

Buccal swab:Massage the buccal cavity (the space near the upper rear molars between the cheek and the teeth) for 30 seconds and swab the area; obtain a generous amount of saliva. Place swab in a sterile tube containing 2-3 ml of viral transport medium (VTM) (see Approved swabs and media).

Throat swab:Vigorously swab tonsillar areas and posterior nasopharynx with a viral culturette. Use tongue blade to depress tongue to prevent contamination of swab with saliva. Place swab into VTM.

Urine specimen: Collect 10 ml of urine in a STERILE urine specimen container. First-morning voided specimens are ideal, but any urine collection is adequate. Have patient void directly into container, collecting from the first part of the urine stream if possible.

Approved swabs and media

Appropriate

  • VTM
  • M5
  • M4
  • MEM
  • Saline
  • Balanced salt solutions (BSS)
  • Sterile isotonic solutions
  • Phosphate buffered salines (PBS)
  • Stuart’s Liquid Media
  • BBL Culture Swab
  • Culturettes

Not Appropriate

  • Wood-tipped applicators
  • Calcium-alginate tipped swabs
  • Charcoal swabs
  • Gel swabs
  • Anaerobic media

Transporting specimens to MDH

  • Label all tubes/containers with:
    • Patient name
    • Patient date of birth
    • Date specimen collected
    • Specimen type
  • Include an Infectious Disease Testing and Submission Form for each specimen.
  • Fill out the form as completely as possible and be sure to indicate which test is requested.
  • Specimens should be kept and transported at refrigeration temperature (2-8° C).
  • Before shipping, always consult with an MDH epidemiologist at 651-201-5414 or 877-676-5414.
  • Send to MDH Public Health Laboratory via overnight shipping.
  • For help with packaging and shipping, call MDH-PHL Biological Accessioning at 651-201-4953.
  • Results will be sent via fax to the submitting laboratory.

Send specimens to arrive Monday-Friday before 4:30 p.m. to:
MDH Public Health Laboratory
Attn: Biological Accessioning
601 Robert St. N.
St. Paul, MN 55155-2531

Updated Friday, June 19, 2015 at 11:39AM