Australian vaccine preventable disease epidemiological review series: mumps 2008-2012

In 2007, Australia recorded the highest notification rate (2.8 per 100,000) for mumps since it became notifiable, with outbreaks in Western Australia and the Northern Territory. Of particular concern was the number of cases seen in vaccinated individuals. The aim of this study was to review subsequent epidemiological data. Notification, hospitalisation and mortality data from the National Notifiable Diseases Surveillance System, the National Hospital Morbidity Database and Australian Bureau of Statistics (ABS) respectively, from 2008 to 2012 for notifications and 2008 to 2011 for hospitalisations and deaths, were analysed by age, year and jurisdiction. ABS population data were used to calculate rates. National mumps notification rates decreased from 1.3 per 100,000 in 2008 to 0.4 per 100,000 in 2010, but then increased to 0.9 per 100,000 in 2012, predominantly due to increased notifications in New South Wales (1.4 per 100,000). Hospitalisation rates remained stable at 0.4 per 100,000 over the 2008-2011 period. The median age of notified cases was 30 years and for hospitalisations, 27 years. The highest rate of notifications and hospitalisations was in the 25-34 years age group. Completeness of vaccination status ranged from 16% to 39%. The increasing trend in mumps notifications needs to be closely monitored. Improved data quality, in particular on vaccination status, is needed to inform the monitoring of vaccine effectiveness. In March 2014 the World Health Organization certified that Australia had achieved measles elimination. Greater availability of case history (vaccination status and place of acquisition) and genotyping data would facilitate an assessment of Australia's progress in relation to mumps elimination.