Key points
- Laboratory testing should be performed if mumps is suspected.
- Collect buccal swab specimen as soon after parotitis onset as possible.
- Real-time RT-PCR is the preferred method to confirm mumps; it's more sensitive and specific than serologic assays to detect IgM.
- The successful detection of mumps virus depends primarily on the timing of collection and quality of the clinical sample.
Overview
Testing for mumps is an important public health action. The timing of specimen collection can play an important role in accurate test outcomes.
At the onset of a suspected mumps outbreak, patients suspected to have mumps should be tested by rRT-PCR to confirm mumps and rule out other possible etiologies. However, once a mumps outbreak is confirmed, jurisdictions should consider alternate strategies to ensure efficient use of resources available for laboratory testing.
Types of tests
Real-time RT-PCR:
Molecular assays, such as real-time reverse transcription PCR (real-time RT-PCR) can detect mumps viral RNA. rRT-PCR testing is preferred to serologic testing for mumps whenever possible. This is because rRT-PCR is more sensitive and specific than serologic assays to detect IgM. testing allows for opportunities for molecular characterization of circulating mumps viruses.
rRT-PCR is performed by almost all state and local public health laboratories, the APHL-VPD Reference Centers, and CDC. The APHL-VPD Reference Centers and CDC also perform genotyping, based on the sequence of the gene coding for the small hydrophobic (SH) protein.
Serology testing:
IgM can aid in diagnosis but is not confirmatory. The availability of assays to detect IgM (to aid in the diagnosis of acute mumps infection) and to measure IgG antibodies (to document previous exposure to mumps) varies among laboratories.
Your state health department can provide guidance regarding available laboratory services in your state. At the direction of your state health department, providers and health departments may send serum specimens from suspected mumps cases to CDC for IgM detection. Use a capture IgM enzyme immunoassay that incorporates a recombinant mumps nucleocapsid protein as the antigen.
Specimen collection overview
CDC recommends collection of a buccal swab specimen for rRT-PCR if it has been 3 or fewer days since symptom onset. Collect specimens as soon after symptom onset as possible.
If it has been more than 3 days since symptom onset, collect a buccal swab specimen for rRT-PCR and a serum specimen for IgM detection.
Recurrent parotitis
From 1919 (pre-vaccine) to recent outbreaks, there have been reports of recurrent parotitis (swollen parotid glands). Reports describe parotitis that occurs on one side, resolves, then reoccurs days to weeks later on the other side. CDC laboratories detected mumps RNA during both early and late episodes of parotitis.
- Both buccal swab and serum specimens should be collected from each episode of parotitis.
- Isolate patients beginning at the onset of the most recent parotitis.
Submitting specimens
Please contact your state or local health department to determine where to submit specimens and how to ship them.
Virus detection
- Confirmed case: The laboratory criteria for the CSTE case definition for mumps designates mumps cases with confirmatory laboratory evidence (including those with a positive rRT-PCR result) as confirmed.
- Probable case: Cases that are IgM positive and meet the clinical criteria of ≥2 day-duration of parotitis or other salivary gland swelling or with a mumps-related complication are classified as probable.
- Suspect case: Those with an IgM positive result that do NOT meet the clinical criteria are classified as suspect only if there is documentation that mumps was suspected.
Positive rRT-PCR result
A positive rRT-PCR signal indicates the presence of mumps virus RNA in the patient sample. A positive rRT-PCR result provides laboratory confirmation of mumps infection in persons with symptoms consistent with mumps.
Genetic analysis of mumps
Negative rRT-PCR or IgM result
Failure to detect mumps virus RNA by rRT-PCR and/or a negative IgM result specimen from a person with clinically compatible mumps symptoms does not rule out mumps. This is because successful detection of mumps virus depends primarily on the timing of collection and quality of the clinical sample. The following factors can affect mumps detection:
- Vaccinated individuals may shed virus for a shorter period and in smaller amounts, degrading the sample and hampering successful detection.
- Viral RNA may not be detectable in specimens that have been collected, stored or shipped improperly. IgM may be transient or absent and therefore not detected.
- In outbreaks among two-dose vaccine recipients, mumps virus RNA was detected in specimen from 30%–71% of case-patients if the specimen were collected within 3 days following onset of parotitis. IgM was detected in 13%–50% of these cases.12
Positive IgG result
The presence of mumps-specific IgG, as detected using a serologic assay (EIA or IFA), does not necessarily predict the presence of neutralizing antibodies or protection from mumps disease.
- Bitsko RH, Cortese MM, Dayan GH, Rota PA, Lowe L, Iversen SC, Bellini WJ. Detection of RNA of mumps virus during an outbreak in a population with a high level of measles, mumps, and rubella vaccine coverage. J Clin Microbiol 2008;46:1101–3.
- Rota JS, Rose JB, Doll MK, McNall RJ, McGrew M, Williams N, Lopareva EN, Barskey AE, Punsalang Jr A, Rota PA, Oleszko WR, Hickman CJ, Zimmerman DM, Bellini WJ. Comparison of the sensitivity of laboratory diagnostic methods from a well-characterized outbreak of mumps in New York City in 2009. Clin Vaccine Immunol. 2013;20:391-6.
- Briss PA, Fehrs LJ, Parker RA, Wright PF, Sannella EC, Hutcheson RH, Schaffner W. Sustained transmission of mumps in a highly vaccinated population: assessment of primary vaccine failure and waning vaccine-induced immunity. J Infect Dis 1994;169:77–82.
- Davidkin I, Jokinen S, Paananen A, Leinikki P, Peltola H. Etiology of mumps-like illnesses in children and adolescents vaccinated for measles, mumps, and rubella. J Infect Dis 3005;191:719–23.
- Gouma S, Vermeire T, Van Gucht S, et al. Differences in antigenic sites and other functional regions between genotype A and G mumps virus surface proteins. Sci Rep. 2018;8(1):13337.
- Gut JP, Lablache C, Behr S, Kirn A. Symptomatic mumps virus reinfections. J Med Virol 1995;45:17–23.
- Hatchette TF, Mahony JB, Chong S, LeBlanc JJ. Difficulty with mumps diagnosis: what is the contribution of mumps mimickers? J Clin Virol 2009; 46:381-3.
- Jin, L., et al., Genomic diversity of mumps virus and global distribution of the 12 genotypes. Rev Med Virol, 2015. 25(2): p. 85-101.
- Jin L, Feng Y, Parry R, Cui A, Lu Y. Real-time PCR and its application to mumps rapid diagnosis. J Med Virol 2007; 79:1761-7.
- Krause CH, Eastick K, Ogilvie MM. Real-time PCR for mumps diagnosis on clinical specimens–comparison with results of conventional methods of virus detection and nested PCR. J Clin Virol 2006; 37:184-9.
- Krause CH., Molyneaux PJ, Ho-Yen DO, McIntyre P, Carman WF, Templeton KE. Comparison of mumps-IgM ELISAs in acute infection. J Clin Virol 2007;38:153–6.
- L'Huillier AG, Eshaghi A, Racey CS, et al. Laboratory testing and phylogenetic analysis during a mumps outbreak in Ontario, Canada. Virol J 2018; 15:98.
- Maillet M, Bouvat E, Robert N, et al. Mumps outbreak and laboratory diagnosis. J Clin Virol 2015; 62:14-9.
- Narita M, Matsuzono Y, Takekoshi Y, Yamada S, Itakura O, Kubota M, Kikuta H, Togashi T. Analysis of mumps vaccine failure by means of avidity testing for mumps virus-specific immunoglobulin G. Clin Diagn Lab Immunol 1998;5:799–803.
- Nunn A, Masud S, Krajden M, Naus M, Jassem AN. Diagnostic Yield of Laboratory Methods and Value of Viral Genotyping during an Outbreak of Mumps in a Partially Vaccinated Population in British Columbia, Canada. J Clin Microbiol. 2018;56(5).
- Rota JS, Turner JC, Yost-Daljev MK, Freeman M, Toney DM, Meisel E, Williams N, Sowers SB, Lowe L, Rota PA, Nicolai LA, Peake L, Bellini WJ. Investigation of a mumps outbreak among university students with two measles-mumps-rubella (MMR) vaccinations, Virginia, September–December 2006. J Med Virol 2009;81:1819–25.
- Rubin SA, Qi L, Audet SA, et al. Antibody induced by immunization with the Jeryl Lynn mumps vaccine strain effectively neutralizes a heterologous wild-type mumps virus associated with a large outbreak. J Infect Dis. 2008;198(4):508-515.
- Sakata H, Tsurudome M, Hishiyama M, Ito Y, Sugiura A. Enzyme-linked immunosorbent assay for mumps IgM antibody: comparison of IgM capture and indirect IgM assay. J Virol Methods 1985;12:303–11.
- Sartorius B, Penttinen P, Nilsson J, Johansen K, Jönsson K, Arneborn M, Löfdahl M, Giesecke J. An outbreak of mumps in Sweden, February–April 2004. Euro Surveill 2005;10 (9):pii=559. Available at https://www.eurosurveillance.org/content/10.2807/esm.10.09.00559-enexternal icon
- Tan KE, Anderson M, Krajden M, Petric M, Mak A, Naus M. Mumps virus detection during an outbreak in a highly unvaccinated population in British Columbia. Can J Public Health 2011; 102:47-50.
- Vermeire T, Barbezange C, Francart A, et al. Sera from different age cohorts in Belgium show limited cross-neutralization between the mumps vaccine and outbreak strains. Clin Microbiol Infect. 2018.