title: Risk factors for surgical site infection after cardiac surgery: the role of endogenous flora.
abstract: OBJECTIVE
  The study's objective was to assess predictors of surgical site infection (SSI) after cardiac surgery and the relationship of perioperative nasal carriage of Staphylococcus species with the development of SSI.
  
  
  METHODS
  Surveillance for infections was performed, and anterior nares cultures of patients who underwent cardiac surgery were obtained. Preoperative risk factors were analyzed, and staphylococcal isolates from nares and SSI were compared using pulsed-field gel electrophoresis.
  
  
  RESULTS
  Twelve patients had 14 SSIs (5.7 infections/100 surgeries). Two risk factors were significantly associated with SSI: smoking (P = .002, confidence interval(95) 1.1-1.4, relative risk = 1.3) and increased body mass index (P = .003, confidence interval(95) 2.8-99.8, relative risk = 16.8). A total of 5 of 8 infected patients (62.5%) for whom nares cultures were available had identical strains in their nares and SSI.
  
  
  CONCLUSIONS
  Smoking and body mass index were predictors of SSI. Approximately 2 of 3 infected patients for whom nares cultures were obtained had an SSI that was likely from an endogenous source.
authors.affiliation: Department of Eidemiology, Columbia University School of Nursing and New York Presbyterian Hospital, New York, New York 10032, USA.
authors.forename: Janet P
authors.initials: JP
authors.lastname: Haas
authors.forename: Ann M
authors.initials: AM
authors.lastname: Evans
authors.forename: Karen E
authors.initials: KE
authors.lastname: Preston
authors.forename: Elaine L
authors.initials: EL
authors.lastname: Larson
mesh_terms: D000368:Aged; D015992:Body Mass Index; D006348:Cardiac Surgical Procedures; D002353:Carrier State / Q000382:microbiology; D016001:Confidence Intervals; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009666:Nose / Q000382:microbiology*; D012306:Risk; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D013210:Staphylococcus / Q000302:isolation & purification*; D013211:Staphylococcus aureus / Q000302:isolation & purification; D013530:Surgical Wound Infection / Q000453:epidemiology* / Q000382:microbiology / Q000517:prevention & control