title: Hospitalised adult patients with pandemic (H1N1) 2009 influenza in Melbourne, Australia.
abstract: OBJECTIVE
  To describe the case characteristics and outcomes of patients hospitalised with pandemic (H1N1) 2009 influenza infection during the first 2 months of the epidemic.
  
  
  METHODS
  Prospective case series of 112 patients admitted to seven hospitals in Melbourne with laboratory-confirmed pandemic (H1N1) 2009 influenza between 1 May and 17 July 2009.
  
  
  METHODS
  Details of case characteristics, risk factors for severe disease, treatment and clinical course.
  
  
  RESULTS
  Of 112 hospitalised patients, most presented with cough (88%) and/or fever (82%), but several (4%) had neither symptom. A quarter of female patients (15) were pregnant or in the post-partum period. Patients presenting with multifocal changes on chest x-ray had significantly longer hospital lengths of stay, and were more likely to require intensive care unit admission. Thirty patients required admission to an intensive care unit, and three died during their acute illness. The median length of intensive care admission was 10.5 days (interquartile range, 5-16 days).
  
  
  CONCLUSIONS
  This study highlights risk factors for severe disease, particularly pregnancy. Clinical and public health planning for upcoming influenza seasons should take into account the spectrum and severity of clinical infection demonstrated in this report, and the need to concentrate resources effectively in high-risk patient groups.
authors.affiliation: Victorian Infectious Diseases Service, Royal Melbourne Hospital, Melbourne, VIC, Australia. justin.denholm@mh.org.au
authors.forename: Justin T
authors.initials: JT
authors.lastname: Denholm
authors.forename: Claire L
authors.initials: CL
authors.lastname: Gordon
authors.forename: Paul D
authors.initials: PD
authors.lastname: Johnson
authors.forename: Saliya S
authors.initials: SS
authors.lastname: Hewagama
authors.forename: Rhonda L
authors.initials: RL
authors.lastname: Stuart
authors.forename: Craig
authors.initials: C
authors.lastname: Aboltins
authors.forename: Cameron
authors.initials: C
authors.lastname: Jeremiah
authors.forename: James
authors.initials: J
authors.lastname: Knox
authors.forename: Garry P
authors.initials: GP
authors.lastname: Lane
authors.forename: Adrian R
authors.initials: AR
authors.lastname: Tramontana
authors.forename: Monica A
authors.initials: MA
authors.lastname: Slavin
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Schulz
authors.forename: Michael
authors.initials: M
authors.lastname: Richards
authors.forename: Chris J
authors.initials: CJ
authors.lastname: Birch
authors.forename: Allen C
authors.initials: AC
authors.lastname: Cheng
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015331:Cohort Studies; D004196:Disease Outbreaks; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000175:diagnosis / Q000453:epidemiology / Q000628:therapy; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome; D014739:Victoria / Q000453:epidemiology; D055815:Young Adult