Australian Influenza Surveillance Report and Activity Updates

The Australian Influenza Surveillance Report and Activity Updates are compiled from a number of data sources, which are used to monitor influenza activity and severity in the community. These data sources include laboratory-confirmed notifications to NNDSS; influenza associated hospitalisations; sentinel influenza-like illness (ILI) reporting from general practitioners; ILI-related community level surveys; and sentinel laboratory testing results.

Page last updated: 10 November 2017

The Australian Influenza Surveillance Report (AISR) is published on a fortnightly basis during the influenza season, typically between May and October. Influenza activity updates may be published outside of the seasonal period.

Australian Influenza Surveillance Report - 2017 Season Summary


  • Nationally, influenza activity declined this reporting fortnight after reaching a peak in mid-August. Surveillance systems indicate that national activity levels have returned to or are approaching baseline levels.
  • The peak week of national influenza activity this season has been at comparable or higher levels than in recent years, with high activity persisting at the peak of the season for a number of weeks.
  • There has been more than two and a half times the number of laboratory confirmed notifications of influenza reported to the National Notifiable Diseases Surveillance System (NNDSS) this year when compared with the same period last year. An earlier season onset and introduction of rapid testing have contributed, in part, to this increase. Administrative backlogs in data entry experienced in some jurisdictions are likely to alter the pattern of notifications once the backlog is resolved.
  • National indicators of influenza-like illness (ILI) continued to decline in the reporting fortnight and are within historical ranges for this time of year. The most commonly detected respiratory virus in patients presenting to sentinel general practitioners with ILI this reporting fortnight was rhinovirus.
  • While influenza A(H3N2) was the dominant circulating influenza virus throughout the season, influenza B is currently the dominant circulating influenza virus nationally and in many jurisdictions.
  • Notification rates this year to date have been highest in adults aged 80 years and older, with a secondary peak in young children, aged 5 to 9 years. This is consistent with previous seasons where influenza A(H3N2) and influenza B, respectively, have dominated.
  • Admissions to sentinel hospitals with confirmed influenza decreased this reporting fortnight, following a peak in late August. The large number of admissions this season is consistent with the higher number of cases in the community, and not necessarily reflecting an increase in severity of infection.
  • The severity of infection in people hospitalised with influenza was on the low end of the historic range.
  • While an increased number of deaths have been reported in 2017, mortality is consistent with recent years when taking into account the significant increase in notifications of laboratory confirmed influenza and the predominance of influenza A(H3N2) throughout the season. Most of the reported deaths have been in the elderly.
  • The effectiveness of the 2017 seasonal influenza vaccine has been preliminarily estimated to be low.
  • This will be the final Australian Influenza Surveillance Report for 2017, unless unusual activity becomes apparent over the summer months.

Full Report

Data considerations

The AISR aims to increase awareness of influenza activity in Australia by providing an analysis of the various surveillance data sources throughout Australia. While every care has been taken in preparing this report, the Commonwealth does not accept liability for any injury or loss or damage arising from the use of, or reliance upon, the content of the report. Delays in the reporting of data may cause data to change retrospectively. For further details about information contained in this report please refer to the AISR 2017 Data Consideration:

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Previous Reports and Updates

State and Territory Surveillance Reports

For further information regarding current influenza activity at the jurisdictional level, please refer to the following State and Territory departments of health surveillance reports:

Annual Reports

National Influenza Surveillance Scheme

This paper provides a comprehensive summary and analysis of the National Influenza Surveillance Scheme, including surveillance systems that function outside of the Scheme, in 2015. The Scheme is coordinated by the Australian Government Department of Health and supported by a number of surveillance systems that aim to be nationally representative and monitor important aspects of severity, incidence and virology. Influenza activity monitored through its systems is presented in reports available on this page. Several jurisdictionally based surveillance systems that operate outside of the Scheme are used to inform local influenza activity trends. This paper describes the strengths and limitations of these influenza surveillance systems in terms of the aspects of influenza activity that they inform  and their contribution to the overall monitoring of influenza activity in Australia.

Accessibility Issues

Should you encounter issues in accessing the information contained either on this webpage or within the downloadable full reports please email flu ( or contact the Department of Health switchboard on 02 6289 1555 or 1800 020 103.

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