title: Staphylococcus aureus bloodstream infection: a pooled analysis of five prospective, observational studies.
abstract: OBJECTIVE
  Staphylococcus aureus bacteraemia is a common, often fatal infection. Our aim was to describe how its clinical presentation varies between populations and to identify common determinants of outcome.
  
  
  METHODS
  We conducted a pooled analysis on 3395 consecutive adult patients with S. aureus bacteraemia. Patients were enrolled between 2006 and 2011 in five prospective studies in 20 tertiary care centres in Germany, Spain, United Kingdom, and United States.
  
  
  RESULTS
  The median age of participants was 64 years (interquartile range 50-75 years) and 63.8% were male. 25.4% of infections were associated with diabetes mellitus, 40.7% were nosocomial, 20.6% were caused by methicillin-resistant S. aureus (MRSA), although these proportions varied significantly across studies. Intravenous catheters were the commonest identified infective focus (27.7%); 8.3% had endocarditis. Crude 14 and 90-day mortality was 14.6% and 29.2%, respectively. Age, MRSA bacteraemia, nosocomial acquisition, endocarditis, and pneumonia were independently associated with death, but a strong association was with an unidentified infective focus (adjusted hazard ratio for 90-day mortality 2.92; 95% confidence interval 2.33 to 3.67, p < 0.0001).
  
  
  CONCLUSIONS
  The baseline demographic and clinical features of S. aureus bacteraemia vary significantly between populations. Mortality could be reduced by assiduous MRSA control and early identification of the infective focus.
authors.affiliation: Institute for Medical Microbiology, Immunology and Hygiene, University of Cologne, Germany. Electronic address: achim.kaasch@uk-koeln.de.
authors.forename: Achim J
authors.initials: AJ
authors.lastname: Kaasch
authors.affiliation: Department of Infection and Tropical Medicine, Hull and East Yorkshire Hospitals NHS Trust, Hull, United Kingdom.
authors.forename: Gavin
authors.initials: G
authors.lastname: Barlow
authors.affiliation: Centre for Clinical Infection and Diagnostics Research, Department of Infectious Diseases, Kings College London & Guy's and St. Thomas' Hospitals NHS Foundation Trust, London, United Kingdom.
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Edgeworth
authors.affiliation: Department of Medicine, Duke University, Durham, NC, USA.
authors.forename: Vance G
authors.initials: VG
authors.lastname: Fowler
authors.affiliation: Institute of Medical Statistics, Informatics and Epidemiology, University of Cologne, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Hellmich
authors.affiliation: Department of Infectious Diseases and Microbiology, Royal Free London NHS Foundation Trust, London, United Kingdom.
authors.forename: Susan
authors.initials: S
authors.lastname: Hopkins
authors.affiliation: Center for Infectious Diseases and Travel Medicine, Department of Medicine, University Hospital of Freiburg, Germany.
authors.forename: Winfried V
authors.initials: WV
authors.lastname: Kern
authors.affiliation: Department of Infectious Diseases and Microbiology, Brighton and Sussex University Hospitals NHS Trust, Brighton, United Kingdom.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Llewelyn
authors.affiliation: Center for Infectious Diseases and Travel Medicine, Department of Medicine, University Hospital of Freiburg, Germany.
authors.forename: Siegbert
authors.initials: S
authors.lastname: Rieg
authors.affiliation: Infectious Diseases and Clinical Microbiology Unit, Hospital Universitario Virgen Macarena; Department of Medicine, University of Seville, Seville, Spain.
authors.forename: Jesús
authors.initials: J
authors.lastname: Rodriguez-Baño
authors.affiliation: Department of Infectious Diseases, Oxford University Hospitals NHS Trust, Oxford, United Kingdom.
authors.forename: Matthew
authors.initials: M
authors.lastname: Scarborough
authors.affiliation: Institute for Medical Microbiology, Immunology and Hygiene, University of Cologne, Germany.
authors.forename: Harald
authors.initials: H
authors.lastname: Seifert
authors.affiliation: Service of Infectious Diseases, Hospital Clínic of Barcelona, Barcelona, Spain.
authors.forename: Alex
authors.initials: A
authors.lastname: Soriano
authors.affiliation: Department of Microbiology, Plymouth Hospitals NHS Trust, Plymouth, United Kingdom.
authors.forename: Robert
authors.initials: R
authors.lastname: Tilley
authors.affiliation: Department of Medicine, University of Cambridge, Cambridge, United Kingdom.
authors.forename: M Estée
authors.initials: ME
authors.lastname: Tőrők
authors.affiliation: Institute of Medical Statistics, Informatics and Epidemiology, University of Cologne, Germany.
authors.forename: Verena
authors.initials: V
authors.lastname: Weiß
authors.affiliation: Department of Microbiology, University College London Hospitals NHS Foundation Trust, London, United Kingdom.
authors.forename: A Peter R
authors.initials: AP
authors.lastname: Wilson
authors.affiliation: Centre for Clinical Infection and Diagnostics Research, Department of Infectious Diseases, Kings College London & Guy's and St. Thomas' Hospitals NHS Foundation Trust, London, United Kingdom; Nuffield Department of Medicine, Oxford University, Oxford, United Kingdom.
authors.forename: Guy E
authors.initials: GE
authors.lastname: Thwaites
mesh_terms: D000368:Aged; D016470:Bacteremia / Q000453:epidemiology* / Q000401:mortality; D003428:Cross Infection; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000401:mortality; D013211:Staphylococcus aureus
keywords: Bacteraemia; Mortality; Pooled analysis; Staphylococcus aureus bloodstream infection