Australian Influenza Surveillance Report - week ending 27 October 2017 (#12/2017)

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: 06 January 2017

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 12 - week ending 27 October 2017


  • 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.

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Previous Reports and Updates

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