Mumps

Queensland Health Guidelines for Public Health Units

Infectious Agent

The agent is the mumps virus, a member of the Rubulavirus genus (family Paramyxoviridae).


Case Definitions and Notification Criteria

Report confirmed and probable cases.


Confirmed case

A confirmed case requires laboratory definitive evidence only.

Laboratory definitive evidence

  • Isolation of mumps virus*

OR

  • Detection of mumps virus by nucleic acid testing*

OR

  • IgG seroconversion or a significant increase in antibody level or a fourfold or greater rise in the titre in paired sera to mumps virus EXCEPT if the case has received a mumps-containing vaccine 8 days to 8 weeks prior to specimen collection (NOTE: paired sera must be tested in parallel).

* If mumps vaccine has been given in the 25 days prior to illness onset, wild-type virus must be detected to be classified as a confirmed case. Vaccine-associated mumps illness (genotype A) is not notifiable, but rather should be reported as an adverse event following immunisation.

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Probable case

A probable case requires either:

  • laboratory suggestive evidence AND clinical evidence

OR

  • clinical evidence AND epidemiological evidence

OR

  • clinical evidence in a case who is a member of a community, where community outbreak criteria have already been met.

Laboratory suggestive evidence

Detection of mumps-specific IgM antibody EXCEPT

  • if ruled out by a more specific IgM serology testing at a jurisdictional public health laboratory

OR

  • if the case has received a mumps containing vaccine eight days to eight weeks before testing.

In vaccinated populations, IgM detection is of limited value as IgM is often not detectable in immunised individuals with mumps.

Clinical evidence

A clinically compatible illness (e.g., swelling of the parotid or other salivary glands lasting at least 2 days, or orchitis) without other apparent cause.

Epidemiological evidence

An epidemiological link is established when there is:

1. contact between two people, with clinical symptoms suggestive of mumps, involving a plausible mode of transmission at a time when:

  • none of them is likely to be infectious (6–7 days before onset of parotitis to 9 days after onset of parotitis)

AND

  • the other has an illness that starts within approximately 12–25 days after this contact

AND

2. at least one case in the chain of epidemiologically linked cases (which may involve many cases) is a laboratory confirmed case.

Community outbreak criteria

Criteria are met when more than the expected incidence of confirmed and/or probable cases occur in a defined community.

Notification Procedure

Pathology Laboratories to notify on pathological confirmation, by usual means.

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Objectives of surveillance

  1. To detect outbreaks of mumps so that public health measures can be promptly implemented.
  2. To monitor the epidemiology of mumps in Queensland (including the impact of mumps vaccination).

Public Health Significance and Occurrence

The epidemiology of mumps is changing. Decades after widespread mumps vaccination was introduced in developed countries, it is clear that vaccine-derived immunity can wane, in part due to the absence of natural boosting from exposure to the widespread circulation of wild virus. Individuals with waning immunity plus unvaccinated individuals and primary vaccine failures, can add to an accumulation of susceptible persons. Eventually this may result in infrequent, slowly evolving community outbreaks, typically in older children and adults. This is in contrast to the pre-vaccination endemic era where most mumps cases occurred in young children. At particular risk are those living in settings where overcrowding is common, such as in remote Indigenous communities, college and boarding school dormitories, hostels, and residential care facilities.

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Clinical Features

Mumps typically presents as an acute viral disease characterised by fever, swelling and tenderness of the parotid and/or other salivary glands. Recent outbreaks appear to result in milder course of disease with about one third of infections being subclinical. While pre-vaccination era mumps infections are described as more severe in adults, residual immunity from prior vaccination or childhood infection appears to confer some protection. Where mumps is suspected, a buccal swab PCR collected within 2–3 days post onset is the preferred method for confirming the diagnosis.1 See ‘Testing’.

There may be respiratory symptoms (40–50% of infections especially in children under 5 years of age). Symptomatic aseptic meningitis may present in up to 10% of infections, however permanent neurological sequelae are rare. While orchitis occurs in 20–30% of post pubertal males, sterility resulting from orchitis is extremely rare. Other rare sequelae include sensorineural hearing loss, encephalitis, and pancreatitis. Mumps infection during the first trimester of pregnancy may increase the risk of pregnancy loss, but there are no congenital malformations in children associated with maternal exposure to mumps at any time during pregnancy. Death from mumps is extremely rare.

Testing

PCR testing for mumps can be conducted on CSF, oral fluid, parotid duct (buccal) swabs, urine or seminal fluid collected in the first week of the illness. Buccal swabs should be collected after 30 seconds of parotid gland massage (see CDC video in ‘additional resources’).

Reservoir

Humans.

Mode of Transmission

Mumps is readily spread by droplets and saliva of an infected person.

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Incubation Period

About 16–18 days (range 12–25 days).2

Period of Communicability

Individuals may be infectious from 7 days before to 9 days after the onset of parotitis. For the purposes of case exclusion, maximum infectiousness occurs between 2 days before and 5 days after onset of parotid swelling. Asymptomatic infections can also be communicable.2

Susceptibility

Immunity after either inapparent or symptomatic infections is generally long lasting. Adults born before 1966 are likely to have been infected and may be considered immune even if they did not have recognised disease.3 Vaccine derived immunity may wane. This is supported by data from outbreaks where cases occur in people who have documented vaccination.4 The demonstration of mumps IgG is acceptable evidence of mumps immunity.

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Management

Cases

Investigation

Determine the occupation of the case, noting high risk settings and susceptible contacts.

Obtain vaccination status and travel history.

Restriction

Exclusion from childcare, school, or workplace for 5 days after onset of parotitis if susceptible contacts are present.

Health care workers should be excluded from work for 9 days after the onset of parotid gland swelling or until swelling subsides.5

There is limited evidence on infectiousness in mumps patients without parotitis (e.g., patients who only have nonspecific respiratory symptoms or only have complications like orchitis). In lab-confirmed cases without parotitis, onset of first symptom can be used in place of onset of parotitis to estimate infectious period.6

Isolation

If hospitalised: Droplet and standard precautions apply for 5 days from onset of swelling.5

Counselling

The case should be advised of the nature of the infection and its mode of transmission.

Contacts

Contact Tracing

The long incubation period and subclinical cases make contact tracing difficult, and it is usually not possible to establish the chain of infection. Attempts at tracing and immunising household contacts during an outbreak may be misplaced. Unlike measles, MMR does not provide post-exposure protection for mumps and people already exposed are the least likely to benefit. Rather, efforts to improve immunity to mumps and opportunistically to measles through catch-up or third dose MMR, should target a wider circle of contacts and the at-risk population within the community.

Definition

A person who may not be immune to mumps and may have been exposed to droplets or saliva of an infectious case.

Exclusion

Not excluded.

Management

Although immunisation after exposure to natural mumps does not prevent disease in contacts, those who do not develop the disease would be protected against infection from subsequent exposures and prevent further spread of the disease.
Normal human immunoglobulin is not effective and not recommended.

Counselling

Contacts should be advised of the nature of the infection, its mode of transmission, and to undertake personal surveillance for symptoms.

Community outbreaks/epidemics

An outbreak is defined as more than the expected incidence of cases in a defined community. Outbreak detection requires adequate surveillance and clinical judgement by the Public Health Physician.

Queensland does see occasional slowly evolving outbreaks, including cases in a minority of older persons who may not/no longer be immune. Overcrowded settings allow for greater intensity of transmission. In Queensland, outbreaks have been reported in boarding schools, correctional facilities and discrete Indigenous communities.4

MMR vaccination should be offered opportunistically to everyone who has not had 2 doses of a mumps containing vaccine. This may include bringing forward the second scheduled mumps containing vaccine dose in children.

In an outbreak, the ability to confirm a mumps diagnosis through serology among vaccinated patients is limited. Serological tests in vaccinated patients should be interpreted cautiously, and suspected cases confirmed by RT-PCR testing at the beginning of the outbreak.

Among populations with high coverage with 2 doses of MMR, a third dose of MMR vaccine is indicated for individuals older than 8 years AND born on or after 01/01/1966 who reside in, work in, or regularly visit a defined community or institutional setting with a current mumps outbreak.7 MMR vaccination campaigns will also improve immunity to measles.

Aboriginal and Torres Strait Islander people residing in urban areas may have cultural and family ties with rural and remote Indigenous communities. Public Health Units should inform Aboriginal and Torres Strait Islander Health Services in urban areas about mumps outbreaks in rural and remote Indigenous communities to allow for a third dose of MMR vaccine to be offered to Indigenous individuals who are older than 8 years AND born on or after 01/01/1966 with an epidemiological link to the outbreak.

Once a mumps outbreak has been established by testing, any further cases should be notified to Public Health Units and only tested when deemed necessary. This is to monitor the epidemiology of the outbreak. In an established outbreak, a line list should be completed by the health service to ensure that clinically diagnosed cases are recorded and reported.

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Correctional settings

Prisoners are vulnerable to mumps due to crowding and close living conditions. Mumps may be introduced into the prison setting following transfer of prisoners. In 2017/2018, mumps outbreaks were reported in Queensland prisons. MMR vaccination campaigns should be encouraged in Queensland prisons as a proactive measure to prevent mumps outbreaks.

A third dose of MMR may be offered to prisoners and prison staff born on or after 01/01/1966 for improved outbreak control in a population with waning immunity.7–9

Recommendations for women of childbearing age

MMR vaccines should not be administered to anyone known to be pregnant or attempting to become pregnant. Because of the theoretical risk to the foetus when the pregnant person receives a live virus vaccine, individuals should be counselled to avoid becoming pregnant for 28 days after receipt of MMR vaccine. If the vaccine is inadvertently administered to a pregnant person or a pregnancy occurs within 28 days of vaccination, the person should be counselled about the theoretical risk to the foetus.

Routine pregnancy testing before administering a live-virus vaccine is not recommended. MMR or varicella vaccination during pregnancy should not be considered a reason to terminate pregnancy.

Provision of Normal Human Immunoglobulin following exposure to an infectious case is not recommended, as this has not been shown to be effective in preventing mumps infection.2

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Preventive measures

Vaccination:

  • Mumps containing vaccine, as MMR is recommended for all children at 12 months of age, and MMRV (as the second dose of mumps containing vaccine) is recommended for all children at 18 months of age.
  • Anyone born on or after 01/01/1966 who does not have evidence of two documented doses of mumps containing vaccine is recommended to receive required doses of MMR vaccine.

Public education by health care providers to:

  • Immunise susceptible individuals.
  • Reinforce the importance of hand hygiene.
  • Ensure correct case exclusion times are adhered to.5,11,12

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References

  1. The Public Health Laboratory Network (PHLN). Mumps – Laboratory case definition [Internet]. Australian Government Department of Health and Aged Care; 2015 [cited 2023 Aug 23]. Available from: https://www.health.gov.au/resources/publications/mumps-laboratory-case-definition?language=en
  2. Barskey A, Heymann D. Mumps. In: Control of Communicable Diseases Manual [Internet]. American Public Health Association; 2015 [cited 2023 Aug 30]. (Control of Communicable Diseases Manual). Available from: https://ccdm.aphapublications.org/doi/abs/10.2105/CCDM.2745.103
  3. Aratchige PE, McIntyre PB, Quinn HE, Gilbert GL. Recent increases in mumps incidence in Australia:  the “forgotten” age group in the 1998 Australian Measles Control Campaign. Med J Aust [Internet]. 2008 Oct 20 [cited 2023 Aug 23];189(8). Available from: https://www.mja.com.au/journal/2008/189/8/recent-increases-mumps-incidence-australia-forgotten-age-group-1998-australian
  4. Walker J, Adegbija O, Smoll N, Khan A, Whicker J, Carroll H, et al. Epidemiology of mumps outbreaks and the impact of an additional dose of MMR vaccine for outbreak control in regional Queensland, Australia, 2017-2018. Commun Dis Intell 2018. 2021 Dec 21;45.
  5. National Health and Medical Research Council. Australian Guidelines for the Prevention and Control of Infection in Healthcare [Internet]. 2019. Available from: https://www.nhmrc.gov.au/about-us/publications/australian-guidelines-prevention-and-control-infection-healthcare-2019
  6. Centre for Disease Control and Prevention (CDC). Manual for Surveillance of Vaccine-Preventable Diseases Chapter 9: Mumps [Internet]. 2021 [cited 2023 Aug 23]. Available from: https://www.cdc.gov/vaccines/pubs/surv-manual/chpt09-mumps.html
  7. Cardemil CV, Dahl RM, James L, Wannemuehler K, Gary HE, Shah M, et al. Effectiveness of a Third Dose of MMR Vaccine for Mumps Outbreak Control. N Engl J Med. 2017 Sep 7;377(10):947–56.
  8. Ogbuanu IU, Kutty PK, Hudson JM, Blog D, Abedi GR, Goodell S, et al. Impact of a Third Dose of Measles-Mumps-Rubella Vaccine on a Mumps Outbreak. Pediatrics. 2012 Dec 1;130(6):e1567–74.
  9. Marin M, Marlow M, Moore KL, Patel M. Recommendation of the Advisory Committee on Immunization Practices for Use of a Third Dose of Mumps Virus-Containing Vaccine in Persons at Increased Risk for Mumps During an Outbreak. MMWR Morb Mortal Wkly Rep. 2018 Jan 12;67(1):33–8.
  10. Australian Technical Advisory Group on Immunisation (ATAGI). The Australian Immunisation Handbook. 2023 [cited 2023 Aug 23]. The Australian Immunisation Handbook. Available from: https://immunisationhandbook.health.gov.au/home
  11. Queensland Health. Time Out Poster: Keeping Your Child and other Kids Healthy’ [Internet]; 2022 [cited 2023 Aug 30]. Available from: https://www.health.qld.gov.au/public-health/schools/prevention
  12. National Health and Medical Research Council. Staying healthy: Preventing infectious diseases in early childhood education and care services 4th edition [Internet]. 2013 [cited 2023 Aug 30]. Available from: https://www.nhmrc.gov.au/about-us/publications/staying-healthy-preventing-infectious-diseases-early-childhood-education-and-care-services

Other resources

  1. Centers for Disease Control and Prevention (CDC) ‘Updated recommendations for isolation of persons with mumps’, MMWR, vol. 57, no. 40, pp. 1103-1105, 2008, retrieved from https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5740a3.htm
  2. Department of Health and Aged Care, ‘Mumps’, Australian National Notifiable Diseases Case Definition’; 2022, 2 March 2023, https://www.health.gov.au/resources/publications/mumps-surveillance-case-definition?language=en

Revision history

VersionDateChanges
1.0 February 2012 Full revision of guidelines
2.0 January 2019 Full revision of guideline
3.0 March 2023 Minor review and revision of case definitions

Last updated: 3 October 2023