- Reason for surveillance
- Case definition
- Notification criteria and procedure
- The disease
- Managing single notifications
1. Reason for surveillance
To monitor the epidemiology of the disease and so inform the development of better prevention strategies.
2. Case definition
A confirmed case requires
- Laboratory definitive evidence, or
- Laboratory suggestive evidence and clinical evidence, or
- Both clinical and epidemiological evidence.
Laboratory definitive evidence
- Isolation of mumps virus, or
- Detection of mumps virus by NAT, or
- IgG seroconversion or a significant increase in antibody level or a fourfold or greater rise in titre to mumps virus EXCEPT when there has been recent immunisation.
Laboratory suggestive evidence
Detection of mumps-specific IgM antibody (in the absence of recent mumps vaccination).
A clinically compatible illness characterised by swelling of the parotid or other salivary glands lasting 2 days or more without other apparent cause.
An epidemiological link is established when there is contact between two people involving a plausible mode of transmission at a time when:
- One of them is likely to be infectious (6-7 days before onset of overt parotitis to 9 days after), and
- The other has an illness which starts within approximately 12 to 25 days after this contact, and
- At least one case in the chain of epidemiologically linked cases (which may involve many cases) is laboratory confirmed.
3. Notification criteria and procedure
Mumps is to be notified by:
- Laboratories on microbiological confirmation (ideal reporting by routine mail)
- School principals and directors of child care facilities (ideal reporting by telephone on same day of notification).
Only confirmed cases should be entered onto NCIMS.
4. The disease
The mumps virus.
Mode of transmission
Mumps is transmitted by droplet infection and direct contact with the saliva of infected persons.
The typical incubation period is 16 to 18 days (range 12 to 25 days).
Mumps is communicable from about 6-7 days before onset of overt parotitis to 9 days after onset. Maximum infectiousness occurs from 2 days before to 4 days after onset of illness.
There is often a prodromal illness of low-grade fever, anorexia, malaise, and headache. The case may report earache followed by tenderness and visible swelling of one or both parotid glands and sometimes other salivary glands.
Approximately one third of cases develop a respiratory tract infection without salivary gland swelling.
25% of postpubertal males develop orchitis (usually unilateral). 5% of postpubertal females develop oophritis. Infertility following gonadal involvement is rare.
Meningitis occurs in 1 to 10% of cases and mumps encephalitis occurs in approximately 0.1% of cases. CSF pleocytosis occurs in 50% of cases (many of whom don't have symptoms of meningitis)
Rare clinical manifestations of mumps include migratory polyarthritis, pancreatitis, nephritis and myocarditis.
Infection in the first trimester of pregnancy is associated with spontaneous abortion. Mumps virus crosses the placenta but does not cause congenital malformations.
5. Managing single notifications
Within 5 working days of notification enter on NCIMS confirmed cases only.
The response to a notification will normally be carried out in collaboration with the case's health carers. Regardless of who does the follow-up, PHU staff should ensure that action has been taken to:
- Confirm results of relevant pathology tests, or recommend the tests be done
- For cases without PCR results, collect information on vaccination status (including timing of recent vaccination) and symptoms consistent with clinical case definition
Where a cluster of cases occurs consider initiating a public health investigation to identify people who are not fully vaccinated
Cases requiring hospitalisation should be managed using droplet precautions.
The case or care-giver should be informed about the nature of the infection and the mode of transmission.
Isolation and restriction
Recommend exclusion from work, school, preschool, child care or other settings where there are susceptible individuals, especially young children and infants, for 9 days from the onset of swelling.
None usually required.