OBJECTIVE: To assess the magnitude and severity of the 2012 influenza season in Victoria, Australia using surveillance data from five sources. METHODS: Data from influenza notifications, sentinel general practices, a sentinel hospital network, a sentinel locum service and strain typing databases for 2012 were descriptively analysed. RESULTS: Influenza and influenza-like illness activity was moderate compared to previous years, although a considerable increase in notified laboratory-confirmed influenza was observed. Type A influenza comprised between 83% and 87% of cases from the general practitioners, hospitals and notifiable surveillance data. Influenza A/H3 was dominant in July and August, and most tested isolates were antigenically similar to the A/Perth/16/2009 virus used in the vaccine. There was a smaller peak of influenza type B in September. No tested viruses were resistant to any neuraminidase inhibitor antivirals. Higher proportions of type A/H3, hospitalized cases and those with a comorbid condition indicated for influenza vaccination were aged 65 years or older. Influenza vaccination coverage among influenza-like illness patients was 24% in sentinel general practices and 50% in hospitals. DISCUSSION: The 2012 influenza season in Victoria was average compared to previous years, with an increased dominance of A/H3 accompanied by increases in older and hospitalized cases. Differences in magnitude and the epidemiological profile of cases detected by the different data sources demonstrate the importance of using a range of surveillance data to assess the relative severity of influenza seasons.
OBJECTIVE: To assess the magnitude and severity of the 2012 influenza season in Victoria, Australia using surveillance data from five sources. METHODS: Data from influenza notifications, sentinel general practices, a sentinel hospital network, a sentinel locum service and strain typing databases for 2012 were descriptively analysed. RESULTS: Influenza and influenza-like illness activity was moderate compared to previous years, although a considerable increase in notified laboratory-confirmed influenza was observed. Type A influenza comprised between 83% and 87% of cases from the general practitioners, hospitals and notifiable surveillance data. Influenza A/H3 was dominant in July and August, and most tested isolates were antigenically similar to the A/Perth/16/2009 virus used in the vaccine. There was a smaller peak of influenza type B in September. No tested viruses were resistant to any neuraminidase inhibitor antivirals. Higher proportions of type A/H3, hospitalized cases and those with a comorbid condition indicated for influenza vaccination were aged 65 years or older. Influenza vaccination coverage among influenza-like illnesspatients was 24% in sentinel general practices and 50% in hospitals. DISCUSSION: The 2012 influenza season in Victoria was average compared to previous years, with an increased dominance of A/H3 accompanied by increases in older and hospitalized cases. Differences in magnitude and the epidemiological profile of cases detected by the different data sources demonstrate the importance of using a range of surveillance data to assess the relative severity of influenza seasons.
Authors: Emma R Miller; James E Fielding; Kristina A Grant; Ian G Barr; Georgina Papadakis; Heath A Kelly Journal: Commun Dis Intell Q Rep Date: 2008-03
Authors: D M Skowronski; N Z Janjua; G De Serres; J A Dickinson; A-L Winter; S M Mahmud; S Sabaiduc; J B Gubbay; H Charest; M Petric; K Fonseca; P Van Caeseele; T L Kwindt; M Krajden; A Eshaghi; Y Li Journal: Euro Surveill Date: 2013-01-31
Authors: Brian S Finkelman; Cécile Viboud; Katia Koelle; Matthew J Ferrari; Nita Bharti; Bryan T Grenfell Journal: PLoS One Date: 2007-12-12 Impact factor: 3.240
Authors: Heath A Kelly; Kristina A Grant; Ee Laine Tay; Lucinda Franklin; Aeron C Hurt Journal: Influenza Other Respir Viruses Date: 2012-11-26 Impact factor: 4.380