title: Nosocomial bacteremia: clinical significance of a single blood culture positive for coagulase-negative staphylococci.
abstract: OBJECTIVE
  To describe the epidemiology of nosocomial coagulase-negative staphylococci (CoNS) bacteremia and to evaluate the clinical significance of a single blood culture positive for CoNS.
  
  
  METHODS
  A 3-year retrospective cohort study based on data prospectively collected through hospital-wide surveillance. Bacteremia was defined according to CDC criteria, except that a single blood culture growing CoNS was not systematically considered as a contaminant. All clinically significant blood cultures positive for CoNS nosocomial bacteremia were considered for analysis.
  
  
  METHODS
  A large university teaching hospital in Geneva, Switzerland.
  
  
  RESULTS
  A total of 2,660 positive blood cultures were identified. Of these, 1,108 (41.7%) were nosocomial; CoNS were recovered from 411 nosocomial episodes (37.1%). Two hundred thirty-four episodes of CoNS bacteremia in the presence of signs of sepsis were considered clinically relevant and analyzed. Crude mortality and associated mortality were 24.4% and 12.8%, respectively. Associated mortality was similar among patients with one positive blood culture and those with two or more (16.2% vs 10.8%, respectively; P = .3). Mortality rates after bacteremia for patients with a single positive blood culture and for those with two or more were 15.3% and 7.0%, respectively, at day 14 (RR, 2.2; CI95, 0.87-5.46) and 20.8% and 11.3%, respectively, at day 28 (RR, 1.9; CI95, 0.9-3.8). On multivariate analysis, only age and a rapidly fatal disease were independently associated with death.
  
  
  CONCLUSIONS
  CoNS bacteremia harbor a significant mortality and a single positive blood culture in the presence of signs of sepsis should be considered as clinically relevant.
authors.affiliation: Infection Control Program, University of Geneva Hospitals, Geneva, Switzerland.
authors.forename: Benoît
authors.initials: B
authors.lastname: Favre
authors.forename: Stéphane
authors.initials: S
authors.lastname: Hugonnet
authors.forename: Luci
authors.initials: L
authors.lastname: Correa
authors.forename: Hugo
authors.initials: H
authors.lastname: Sax
authors.forename: Peter
authors.initials: P
authors.lastname: Rohner
authors.forename: Didier
authors.initials: D
authors.lastname: Pittet
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016470:Bacteremia / Q000382:microbiology*; D003030:Coagulase / Q000378:metabolism; D015331:Cohort Studies; D003428:Cross Infection / Q000382:microbiology*; D006784:Hospitals, Teaching; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013203:Staphylococcal Infections / Q000382:microbiology*; D013210:Staphylococcus / Q000201:enzymology / Q000302:isolation & purification*; D013557:Switzerland
chemical_list: D003030:Coagulase