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: 26 October 2018

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 - fortnight ending 21 October 2018


  • Activity – In the last fortnight, at the national level, indicators for person to person transmission of influenza and influenza-like illness (ILI) continued to decline, after reaching a peak in early September. Activity levels have returned to or are approaching baseline levels.
  • Severity – Clinical severity for the season to date, as measured through the proportion of patients admitted directly to ICU, and deaths attributed to influenza, is moderate.
  • Impact – Currently, the impact of circulating influenza on society, as measured through the proportion of people with ILI taking time off work, and the burden on hospitals, is low.
  • Virology – In the last fortnight, the majority of confirmed influenza cases reported nationally were influenza A (83%), and where subtyping data were available, influenza A(H1N1)pdm09 was the dominant subtype.
  • At-risk populations: Children aged less than 10 years appear to be more commonly infected with influenza; however the severity of illness in this population is on par with other age-groups.
  • Vaccine effectiveness: Based on currently available data, vaccinated individuals were 68% less likely to present to a GP and 66% less likely to be hospitalised due to all influenza, when compared to unvaccinated individuals.
  • This will be the final fortnightly Australian Influenza Surveillance Report for 2018, unless unusual activity becomes apparent over the summer months. A 2018 Season Summary will be released by the end of the year.

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 2018 Data Consideration:

Influenza vaccine efficacy, effectiveness and impact explained

There are three general terms that are used to describe how well a vaccine works in any given influenza season: vaccine efficacy, vaccine effectiveness and vaccine impact. This document provides a general explanation of each of these terms as well as information specific to influenza vaccines.

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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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