Mumps is an acute viral disease caused by paramyxovirus. The classical presentation is parotitis, although up to 30% of cases will not have salivary gland involvement and may pose difficulty in diagnosis. Some complications of mumps have been known to occur at higher rates in adults than in children. Complications include orchitis, aseptic meningitis, encephalitis, sensorineural hearing loss and pancreatitis.3

Relevant vaccine history

1982

  • MM* vaccine funded for all Australian infants at 12 months of age.

1984

  • MM vaccination of Aboriginal and Torres Strait Islander children in the Northern Territory changed from 12 months to 9 months of age.

1989

  • MMR vaccine recommended and funded on the national schedule at 12 months of age (9 months for Aboriginal and Torres Strait Islander infants in the Northern Territory).

1994

  • MMR funded as second dose of mumps-containing vaccine for adolescent females.

1996

  • MMR funded as second dose of mumps-containing vaccine for all adolescents.

1998

  • Recommended age for first dose of MMR vaccine for Aboriginal and Torres Strait Islander children in the Northern Territory increased from 9 months to 12 months of age.
  • Recommended age for second dose of MMR vaccine lowered to 4–5 years.

2013

  • Second dose moved forward to 18 months of age, given as MMRV.

Key points

Despite high vaccination coverage in children, mumps outbreaks have been reported in Australia and overseas, predominantly in adolescents and young adults. One outbreak in Australia particularly affected Aboriginal and Torres Strait Islander people, but there was also a national increase in mumps in other adolescents and young adults. Mumps in these age groups more commonly results in serious disease and complications. A third dose of MMR vaccine for adolescents, to combat waning immunity, could be considered if outbreaks continue.

* MM: measles and mumps

† MMR: measles, mumps and rubella

‡ MMRV: measles, mumps, rubella and varicella

Top of page

Disease trends

Mumps notifications are not included here due to under-reporting of Indigenous status.

During this reporting period, a significant difference in hospitalisation rates was noted between Aboriginal and Torres Strait Islander and other people. There was a spike in the hospitalisation rate for Aboriginal and Torres Strait Islander people in 2007/2008, peaking at 5 per 100,000 (up from 0.4 per 100,000 in 2006/2007); the rates for other people also peaked in that year but were much lower (0.5 per 100,000 in 2007/2008, up from 0.2 per 100,000 in 2005/2006). The rates have since declined among Aboriginal and Torres Strait Islander people to less than 1 per 100,000 population in 2009/2010, which is comparable to the rate in other people (Figure 2.7.1).

Figure 2.7.1: Mumps hospitalisation rates and 95% confidence intervals, selected Australian states,* 2005 to 2010, by Indigenous status

Figure 2.7.1: is a line chart showing Mumps hospitalisation rates and 95% confidence intervals, selected Australian states, 2005 to 2010. A link to a text description follows.

* Jurisdictions with satisfactory data quality over the whole time period; see Appendix A (New South Wales, Northern Territory, Queensland, South Australia, Victoria, Western Australia).

† Hospitalisations where the date of separation was between 1 July 2005 and 30 June 2010.

Top of page

Text description of Figure 2.7.1 (TXT 1 KB)

Top of page

Hospitalisation data are presented for six jurisdictions (all except Tasmania and the Australian Capital Territory) by financial year for the period July 2005 to June 2010. Notification data are not presented due to the low level of completeness of the Indigenous status field in notification records.

A total of 372 hospitalisations for mumps were recorded during this reporting period, of which 43 (13%) were reported in Aboriginal and Torres Strait Islander people (Table 2.7.1). The hospitalisation rates were higher in Aboriginal and Torres Strait Islander people than in other people across all age groups. The highest hospitalisation rates in Aboriginal and Torres Strait Islander people were in the 5–14 years age group (2.1 per 100,000 population), followed closely by the 25–49 years age group (2.0 per 100,000 population) indicating a shift in the affected age group from young children to adults since the introduction of vaccination. The overall Indigenous to non-Indigenous rate ratio was 5.1:1, with the highest rate ratio (7.3:1) in the 5–14 years age group.

Table 2.7.1: Mumps hospitalisations, selected Australian states, 2005 to 2010, by age group and Indigenous status
Age group
(years)
Indigenous status Hospitalisations* (2005–2010)
n Rate Rate ratio

* Hospitalisations (New South Wales, Northern Territory, Queensland, South Australia, Victoria, Western Australia only) where the date of separation was between 1 July 2005 and 30 June 2010.

† Average annual age-specific rate per 100,000 population.

‡ Includes cases with age unknown.

§ Indicates statistically significant, 95% confidence intervals do not overlap 1.0.

0–4
Indigenous
5
1.6
3.4§
Other
29
0.5
5–14
Indigenous
13
2.1
7.3§
Other
36
0.3
15–24
Indigenous
7
1.4
3.1§
Other
63
0.5
25–49
Indigenous
16
2.0
5.4§
Other
132
0.4
>50
Indigenous
2
0.7
3.0§
Other
69
0.2
All ages
Indigenous
43
1.7
5.1§
Other
329
0.3

There were no deaths reported from the five jurisdictions (New South Wales, the Northern Territory, Queensland, South Australia and Western Australia) among Aboriginal and Torres Strait Islander people for the period 2006–2010 with mumps as either the underlying or a contributing cause.

Top of page

Comment

During this reporting period (July 2005 to June 2010), a prolonged outbreak of mumps was recorded with a peak in hospitalisations in 2007/2008, which predominantly affected Aboriginal or Torres Strait Islander adolescents and young adults. This prolonged outbreak occurred predominantly among two epidemiologically linked Aboriginal populations in the Kimberley region (153 cases)49 and the Northern Territory (99 cases).50 Overall, the duration of the outbreak was about 40 weeks. Nearly half of the people affected had received fewer than 2 doses of vaccine (45% in the Northern Territory, 48% in Western Australia).49,50 The cause of the outbreak was likely to be multifactorial, including social factors such as overcrowding leading to increased opportunities for virus transmission, waning immunity, and lower levels of immunity resulting from the adolescents and young adults having received their first dose of MMR vaccine at 9 months of age in the Northern Territory. The outbreak(s) occurred at the same time as a mumps resurgence in non-Indigenous adolescents and young adults across Australia.24

From 1984 to 1998, the initial dose of measles-and-mumps-containing vaccine was recommended at 9 months of age for Aboriginal and Torres Strait Islander children in the Northern Territory but at 12 months of age for non-Indigenous children in that state and for all children in the rest of Australia. This was because Aboriginal and Torres Strait Islander infants were thought to be more vulnerable to the measles epidemics of that era. While vaccination at 9 months of age provides earlier protection, there is a risk of poorer immune response due to immaturity of the immune system and interference by passive (maternal) antibodies. It is possible that this practice led to those children born between 1983 and 1997 in the Northern Territory being at increased risk of mumps due to being less fully protected, even by 2 vaccine doses.50

Over the past 6–7 years, mumps has made a re-emergence globally, including in the United States (US) which in 2006 experienced its largest outbreak since 1987.51 Mumps outbreaks have been reported recently in several other countries including Canada, the United Kingdom (UK), the Netherlands, Israel, Moldova and Belarus.52 As in Australia, the age group predominantly affected by the outbreaks in the US and the UK has been adolescents and young adults. In the US, multiple outbreaks in university residential communities were attributed in part to the lower effectiveness of the mumps vaccine and high-density living.53 This latter factor also applies to remote Aboriginal and Torres Strait Islander communities. Whereas mumps was historically a disease of childhood, the recent outbreaks predominantly involved young adults, nearly all of whom had a history of vaccination during childhood, most with the recommended 2-dose schedule. This evidence of waning immunity has led to suggestions that vaccination with a third dose during adolescence might be an effective measure to prevent outbreaks.51 However, outbreaks in Australia and overseas have subsided without this being routinely implemented.