Page content: Victorian statutory requirement | Infectious agent | Identification | Incubation period | Public health significance & occurrence | Reservoir | Mode of transmission | Period of communicability | Susceptibility & resistance | Control measures | Outbreak measures

Victorian statutory requirement

Mumps (Group B disease) must be notified in writing within five days of diagnosis.

School exclusion: exclude for nine days or until swelling goes down, whichever is sooner.

Infectious agent

Mumps virus is a member of the family Paramyxoviridae.

Identification

Clinical features
Mumps is an acute febrile disease characterised by swelling and tenderness of one or more of the salivary glands, usually the parotid and occasionally the sublingual or submaxillary glands. Respiratory symptoms can occur, particularly in children under five years. Epididymo-orchitis occurs in up to a third of postpuberal males and is most commonly unilateral: sterility is an uncommon complication. Oophoritis occurs in up to 31% of females aged over 15 years and may cause lower abdominal or back pain. Many infections in children less than two years of age are subclinical. Mumps meningitis is a fairly common complication. It usually occurs two to ten days after the onset of parotitis and is self-limited with symptoms lasting three to five days.

Mumps very rarely causes sensorineural deafness, encephalitis and pancreatitis. Mumps during the first trimester may increase the risk of spontaneous abortion but there is no evidence that mumps during pregnancy results in congenital malformations.

Method of diagnosis
The predictive value of parotitis in the diagnosis of mumps is reduced in countries with high immunisation rates such as Australia. The diagnosis should be confirmed serologically by the detection of mumps specific IgM antibody, or a significant rise in mumps IgG antibody in acute and convalescent sera. Mumps virus can also be cultured from swabs of the buccal mucosa and from urine.

Incubation period

The incubation period ranges from 14 to 25 days. It is commonly 15–18 days.

Public health significance & occurrence

Occurrence is worldwide. There is generalised spread of the infection in communities with low immunisation rates; serologic studies show 85% or more of individuals in these communities have evidence of previous mumps infection by adult life. High childhood immunisation rates in Australia have resulted in a dramatic reduction in rates of mumps infection. Unimmunised children and adults, especially males, are the groups at highest risk of infection.

Reservoir

Humans.

Mode of transmission

Transmission occurs through via respiratory aerosols and respiratory droplet spread or by direct contact with contaminated saliva.

Period of communicability

Mumps is communicable from six to seven days before to nine days after the onset of parotitis. Asymptomatic and inapparent cases can also be infectious.

Susceptibility & resistance

Immunity is generally life long and develops after either inapparent or clinical infections. Individuals born prior to 1970 have a high likelihood of natural immunity even if they have had no history of clinical infection.

Control measures

Preventive measures
Live attenuated mumps vaccine is available combined with rubella and measles vaccine (MMR). Vaccination with this vaccine results in seroconversion to all three viruses in over 95% of recipients. Since the MMR vaccine viruses are not transmissible, there is no risk of infection originating from vaccines.

MMR vaccination is recommended for all children at 12 months of age, unless specific contra-indications to the vaccine exist. A second dose is recommended at four years of age, prior to school entry.

Control of case
There is no specific treatment. Cases requiring hospitalisation should be nursed in an isolation room using respiratory precautions until nine days after the onset of glandular swelling.

Exclude cases from school, child care or workplace until nine days after the onset of glandular swelling. Advise parents to keep the child away from other children and susceptible adults for the period of exclusion.

Control of contacts
Susceptible contacts should be offered immunisation with MMR vaccine. Immunoglobulin is not effective in preventing mumps. Contact isolation is not required.

Control of environment
Concurrent disinfection of articles soiled with nose and throat secretions.

Outbreak measures

Susceptible persons should be immunised, especially those at risk of exposure. Those who are not certain of their immunity can be vaccinated if no specific contra-indications to live vaccines exist.