Influenza epidemiology, vaccine coverage and vaccine effectiveness in sentinel Australian hospitals in 2013: the Influenza Complications Alert Network

Authors

  • Allen C Cheng Alfred Health; Monash University, Melbourne, Victoria
  • Dominic E Dwyer University of Sydney, Sydney, New South Wales; Westmead Hospital, Sydney, New South Wales
  • Mark Holmes Royal Adelaide Hospital, Adelaide, South Australia; University of Adelaide, Adelaide, South Australia
  • Louis B Irving Royal Melbourne Hospital, Melbourne, Victoria; University of Melbourne, Melbourne, Victoria
  • Simon GA Brown University of Western Australia, Perth, Western Australia; Royal Perth Hospital, Perth, Western Australia
  • Grant W Waterer University of Western Australia, Perth, Western Australia; Royal Perth Hospital, Perth, Western Australia
  • Tony M Korman Monash Medical Centre, Melbourne, Victoria
  • Cameron Hunter Royal Hobart Hospital, Hobart, Tasmania
  • Saliya Hewagama Alice Springs Hospital, Alice Springs, Northern Territory
  • Nadia D Friedman Barwon Health, Geelong, Victoria
  • Peter A Wark University of Newcastle, Newcastle, New South Wales; John Hunter Hospital, Newcastle, New South Wales
  • Graham Simpson Cairns Base Hospital, Cairns, Queensland
  • John W Upham Princess Alexandra Hospital, Brisbane, Queensland; University of Queensland, Brisbane, Queensland
  • Simon D Bowler Mater Hospitals, Brisbane, Queensland
  • Sanjaya N Senanayake Australian National University, Acton, Australian Capital Territory; The Canberra Hospital, Garran, Australian Capital Territory
  • Tom C Kotsimbos Alfred Health; Monash University, Melbourne, Victoria
  • Paul M kelly ACT Health Directorate, Canberra, Australian Capital Territory

DOI:

https://doi.org/10.33321/cdi.2014.38.22

Keywords:

influenza, vaccine effectiveness

Abstract

The National Influenza Program aims to reduce serious morbidity and mortality from influenza by providing public funding for vaccination to at-risk groups. The Influenza Complications Alert Network (FluCAN) is a sentinel hospital-based surveillance program that operates at 14 sites in all states and territories in Australia. This report summarises the epidemiology of hospitalisations with confirmed influenza, estimates vaccine coverage and influenza vaccine protection against hospitalisation with influenza during the 2013 influenza season. In this observational study, cases were defined as patients admitted to one of the sentinel hospitals, with influenza confirmed by nucleic acid testing. Controls were patients who had acute respiratory illnesses who were test-negative for influenza. Vaccine effectiveness was estimated as 1 minus the odds ratio of vaccination in case patients compared with control patients, after adjusting for known confounders. During the period 5 April to 31 October 2013, 631 patients were admitted with confirmed influenza at the 14 FluCAN sentinel hospitals. Of these, 31% were more than 65 years of age, 9.5% were Indigenous Australians, 4.3% were pregnant and 77% had chronic co-morbidities. Influenza B was detected in 30% of patients. Vaccination coverage was estimated at 81% in patients more than 65 years of age but only 49% in patients aged less than 65 years with chronic comorbidities. Vaccination effectiveness against hospitalisation with influenza was estimated at 50% (95% confidence interval: 33%, 63%, P<0.001). We detected a significant number of hospital admissions with confirmed influenza in a national observational study. Vaccine coverage was incomplete in at-risk groups, particularly non-elderly patients with medical comorbidities. Our results suggest that the seasonal influenza vaccine was moderately protective against hospitalisation with influenza in the 2013 season. Commun Dis Intell 2014;38(2):E143–E149.

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Published

01/06/14

How to Cite

Cheng, Allen C, Dominic E Dwyer, Mark Holmes, Louis B Irving, Simon GA Brown, Grant W Waterer, Tony M Korman, et al. 2014. “Influenza Epidemiology, Vaccine Coverage and Vaccine Effectiveness in Sentinel Australian Hospitals in 2013: The Influenza Complications Alert Network”. Communicable Diseases Intelligence 38 (June):143-49. https://doi.org/10.33321/cdi.2014.38.22.

Issue

Vol. 38 (2014)

Section

Annual report

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