title: Epidemiology of the 2012 influenza season in Victoria, Australia.
abstract: 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.
  
  
  CONCLUSIONS
  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: Victorian Infectious Diseases Reference Laboratory, Melbourne, Australia . ; National Centre for Epidemiology & Population Health, Australian National University, Canberra, Australia .
authors: James
authors: J
authors: Fielding
authors: Kristina
authors: K
authors: Grant
authors: Lucinda
authors: L
authors: Franklin
authors: Sheena
authors: S
authors: Sullivan
authors: Georgina
authors: G
authors: Papadakis
authors: Heath
authors: H
authors: Kelly
authors: Allen
authors: A
authors: Cheng
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D003140:Communicable Disease Control; D018563:Disease Notification / Q000706:statistics & numerical data; D004196:Disease Outbreaks / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D009980:Influenza A virus / Q000302:isolation & purification*; D009981:Influenza B virus / Q000302:isolation & purification*; D007252:Influenza Vaccines / Q000008:administration & dosage; D007251:Influenza, Human / Q000175:diagnosis* / Q000453:epidemiology* / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D012621:Seasons; D014611:Vaccination; D014739:Victoria / Q000453:epidemiology
chemical_list: D007252:Influenza Vaccines