Australian Influenza Surveillance Report - week ending 21 October 2018 (#11/2018)

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 is published on a fortnightly basis during the influenza season, typically between May and October. Influenza activity updates will be published outside of the seasonal period.

Australian Influenza Surveillance Report No 11 - week 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

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Previous Reports and Updates

Annual Reports

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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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