Mumps

Notification requirement for mumps

Mumps is a ‘routine’ notifiable condition. It must be notified by medical practitioners and pathology services in writing within 5 days of diagnosis.

This is a Victorian statutory requirement.

School exclusion for mumps

Exclude for 5 days or until swelling goes down (whichever is sooner).

Infectious agent of mumps

Mumps virus is a member of the Paramyxoviridae family.

Identification of mumps

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 5 years old. Epididymo-orchitis occurs in up to a third of postpuberal males and is most commonly unilateral: sterility is a rare complication.

Oophoritis occurs in up to 31 per cent of females aged over 15 years and may cause lower abdominal or back pain. Many infections in children under 2 years of age are subclinical.

Mumps meningitis is a fairly common complication. It usually occurs 2–10 days after the onset of parotitis; symptoms last 3–5 days and recovery is usually without complications.

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.

Diagnosis

The predictive value of parotitis in the diagnosis of mumps is reduced in countries with high immunisation rates, such as Australia.

Many viral infections produce a parotitis with a similar clinical picture to mumps, including Epstein-Barr, parainfluenza, coxsackie and influenza A viruses.

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 of mumps virus

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

Public health significance and occurrence of mumps

Occurrence is worldwide.

There is generalised spread of the infection in communities with low immunisation rates; serologic studies show 85 per cent or more of individuals in those 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 of mumps virus

Humans.

Mode of transmission of mumps virus

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

Period of communicability of mumps

Mumps virus has been isolated from saliva from 7 days before the onset of salivary gland swelling to 9 days afterwards, however maximum infectiousness occurs between 2 days before and 5 days after onset of salivary gland swelling. Asymptomatic cases can also be infectious

Susceptibility and resistance to mumps

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

Control measures for mumps

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 more than 95 per cent 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 contraindications to the vaccine exist. A second dose as MMRV is recommended at 18 months of age.

Control of case

There is no specific treatment. Cases requiring hospitalisation should be nursed in an isolation room using respiratory precautions until 5 days after the onset of glandular swelling.

Exclude cases from school, childcare or workplace until 5 days after the onset of glandular swelling or until swelling goes down (whichever is sooner). Advise parents to keep the child away from other children and susceptible adults for the period of exclusion.

Control of contacts

Close contacts of all cases who have not received two doses of MMR vaccine should be encouraged to be immunised (provided no contraindications exist), although this may not prevent mumps occurring. Immunoglobulin is not effective in preventing mumps.

Control of environment

Practise concurrent disinfection of articles soiled with nose and throat secretions.

Outbreak measures for mumps

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