Australia's Notifiable Disease Status, 2012: Annual Report of the National
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Annual report National Notifiable Diseases Surveillance System, 2012 National Notifiable Diseases Surveillance System, 2012 Annual report AUSTRALIA’S NOTIFIABLE DISEASE STATUS, 2012: ANNUAL REPORT OF THE NATIONAL NOTIFIABLE DISEASES SURVEILLANCE SYSTEM NNDSS Annual Report Writing Group Abstract • meeting various international reporting requirements, such as providing disease statis- In 2012, 65 diseases and conditions were nation- tics to the World Health Organization (WHO); ally notifiable in Australia. States and territories and reported a total of 243,872 notifications of com- • supporting quarantine activities, which are municable diseases to the National Notifiable the responsibility of the Commonwealth Diseases Surveillance System, an increase of 2% government. on the number of notifications in 2011. In 2012, the most frequently notified diseases were sexu- Information on communicable diseases surveil- ally transmissible infections (99,250 notifications, lance is communicated through several means. 40.7% of total notifications), vaccine preventable The most up-to-date information on topics of diseases (85,810 notifications, 35.2% of total interest is provided at the fortnightly teleconfer- notifications), and gastrointestinal diseases (31,155 ences of the Communicable Diseases Network notifications, 12.8% of total notifications). There Australia (CDNA). A summary of these reports is were 16,846 notifications of bloodborne diseases; available online from the Department of Health 8,305 notifications of vectorborne diseases; web site (http://www.health.gov.au/internet/main/ 1,924 notifications of other bacterial infections; publishing.nsf/Content/cdnareport.htm). 578 notifications of zoonoses; and 5 notifications of quarantinable diseases. Commun Dis Intell The Communicable Diseases Intelligence (CDI) 2015;39(1):E46–E136. quarterly journal publishes surveillance data, annual surveillance reports, short reports, and Keywords: Australia, communicable diseases, articles on the epidemiology and control of com- epidemiology, surveillance municable diseases. Introduction Methods Australia’s notifiable diseases status, 2012, is an Australia is a federation of 6 states (New South annual surveillance report of nationally notifiable Wales, Queensland, South Australia, Tasmania, communicable diseases. Communicable disease Victoria and Western Australia) and 2 territories surveillance in Australia operates at the national, (the Australian Capital Territory and the Northern jurisdictional and local levels. Primary responsibil- Territory). ity for public health action lies with the state and territory health departments. The role of commu- State and territory health departments collect nicable disease surveillance at the national level notifications of communicable diseases under their includes: respective public health legislation. In September 2007, the National Health Security Act 20071 received • identifying national trends; royal assent. This Act provides a legislative basis for • providing guidance for policy development and and authorises the exchange of health information, resource allocation at the national level; including personal information, between jurisdic- • monitoring the need for and impact of national tions and the Commonwealth. The Act provides disease control programs; for the establishment of the National Notifiable Diseases List,2 which specifies the diseases about • coordinating the response to national or multi- which personal information can be provided. The jurisdictional outbreaks; National Health Security Agreement,3 which was • describing the epidemiology of rare diseases signed by Health Ministers in April 2008, estab- that occur infrequently at state and territory lishes the operational arrangements to formalise levels; and enhance existing surveillance and reporting systems; an important objective of the Act. Under E46 CDI Vol 39 No 1 2015 National Notifiable Diseases Surveillance System, 2012 Annual report the Agreement, in 2012 states and territories hepatitis C, tuberculosis, donovanosis, gonococcal forwarded de-identified notification data on the infection and syphilis < 2 years duration) were nationally agreed set of 65 communicable diseases reported from states and territories to NNDSS. to the Australian Government Department of With the exception of hepatitis B and hepatitis C Health for the purposes of national communicable these enhanced data are not included in this disease surveillance, although not all 65 diseases report. These data, along with influenza enhanced were notifiable in each jurisdiction. Data were data, are reported in individual annual reports. electronically updated daily from states and ter- Additional information concerning mortality and ritories. The system was complemented by other specific health risk factors for some diseases were surveillance systems, which provided information obtained from states and territories and included on various diseases, including four that are not in this report. reported through the National Notifiable Diseases Surveillance System (NNDSS): HIV, AIDS and Notification rates for each disease were calculated the classical and variant forms of Creutzfeldt-Jakob using the estimated 2012 mid-year resident popula- disease (CJD). tion supplied by the Australian Bureau of Statistics (Appendix 1 and Appendix 2).6 Where diseases Newly diagnosed HIV infection and AIDS were were not notifiable in a state or territory, national notifiable conditions in all states and territories in rates were adjusted by excluding the population of 2012. These were forwarded to the Kirby Institute that jurisdiction from the denominator. For some for Infection and Immunity in Society. Further diseases, age adjusted rates were calculated using information can be found in the Kirby Institute’s the direct method of standardisation with 2006 annual surveillance report.4 census data as the standard population. All rates are represented as the rate per 100,000 population Surveillance for the classical and variant forms of unless stated otherwise. CJD in Australia has been conducted through the Australian National Creutzfeldt-Jakob Disease Direct age standardised notification rates, using Registry (ANCJDR) since October 2003. CJD is a the method described by the Australian Institute of nationally notifiable disease and has been notifi- Health and Welfare7 were calculated for Aboriginal able in all states and territories since June 2006. and Torres Strait Islander and non-Indigenous Further surveillance information on CJD can be notifications for relevant sexually transmis- found in surveillance reports from the ANCJDR.5 sible infections (STIs) for jurisdictions that had Indigenous status data completed for more than In 2012, the NNDSS core dataset included the 50% of notifications over the period from 2007 to following 5 mandatory data fields: unique record 2012. Where the Indigenous status of a notifica- reference number; notifying state or territory; tion was not completed, these notifications were disease code; confirmation status; and the date counted as non-Indigenous in the analyses. These when the jurisdictional health department was data, however, should be interpreted with cau- notified (notification receive date). In addition, the tion, as STI screening may occur predominately following core but non-mandatory data fields were in specific high risk groups, including in remote supplied where possible: date of birth; age at onset; Aboriginal and Torres Strait Islander populations. sex; Indigenous status; postcode of residence; dis- Recent studies have suggested that higher rates ease onset date; date when the pathology service in Aboriginal and Torres Strait Islander popula- authorised a report or a medical practitioner signed tions may be attributable to higher prevalence and the notification form (notification date); death reinfection rates while others have suggested that status; date of specimen collection; and outbreak it may be due to increased testing and contract reference number (to identify cases linked to an tracing.8 outbreak). Where relevant, information on the spe- cies, serogroups/subtypes and phage types of agents In the national case definitions for chlamydial detected, or isolated, and on the vaccination status infection, gonococcal infection and syphilis, the of the case were collected and reported to NNDSS. mode of transmission cannot be inferred from Data quality was monitored by the Office of the site of infection. Infections in children may Health Protection and the National Surveillance be acquired perinatally (e.g. congenital chla- Committee (NSC). There was a continual process mydia).9 Notifications of chlamydial, gonococ- of improving the national consistency of com- cal and non-congenital syphilis infections were municable disease surveillance through the daily, excluded from analysis of age and sex distribu- fortnightly and quarterly reviews of these data. tion where the case was aged less than 13 years and the infection was able to be determined as While not included in the core national dataset, non-sexually acquired through enhanced sur- enhanced surveillance information for some dis- veillance data, where available. eases (invasive pneumococcal disease, hepatitis B, CDI Vol 39 No 1 2015 E47 Annual report National Notifiable Diseases Surveillance System, 2012 Notes on interpretation interchangeable. Notifications only represent a proportion (the ‘notified fraction’) of the total This report is based on 2012 data from each state incidence