title: A protracted outbreak of Staphylococcus epidermidis infections among patients undergoing valve replacement.
abstract: OBJECTIVE
  To investigate a Staphylococcus epidermidis outbreak among patients undergoing cardiac surgery.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  A 260-bed community referral center.
  
  
  METHODS
  Case-patients were patients with S. epidermidis mediastinitis, endocarditis, or both after valve implantation at Hospital de La Ribera from January to June 2002. The study population included patients undergoing valve surgery at Hospital de La Ribera from January 2000 to June 2002.
  
  
  RESULTS
  From January to June 2002, 8 cases of mediastinitis, endocarditis, or both occurred among 53 patients undergoing cardiac surgery. In the same months of 2000, there had been no cases among 22 patients, and in 2001, only 1 case among 47 patients (P = .095 and P = .034, respectively). In 2002, there were 4 cases of mediastinitis and endocarditis, 3 cases of mediastinitis, and 1 case of endocarditis, all following aortic valve replacement. The epidemic curve suggested a protracted outbreak. Patients with chronic obstructive lung disease were six-fold more likely to be case-patients (95% confidence interval, 1.6-23.8). The mean duration of surgery tended to be longer in non-case-patients (161.4 +/- 57.9 minutes) than in case-patients (123.7 +/- 23.7 minutes) (P = .06).
  
  
  CONCLUSIONS
  The cause of this protracted outbreak was likely multifactorial. Reemphasis of existing policies was associated with resolution of the outbreak.
authors.affiliation: Infectious Diseases Unit, Hospital de La Ribera, Ctra. de Corbera, km. 1, 46600, Alzira, Valencia, Spain.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Bou
authors.forename: Miguel
authors.initials: M
authors.lastname: Peris
authors.forename: Javier
authors.initials: J
authors.lastname: Perpiñan
authors.forename: Pilar
authors.initials: P
authors.lastname: Ramos
authors.forename: Angel
authors.initials: A
authors.lastname: Aguilar
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology; D004196:Disease Outbreaks; D004697:Endocarditis, Bacterial / Q000453:epidemiology; D005260:Female; D006350:Heart Valve Prosthesis / Q000382:microbiology; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects*; D006764:Hospitals, Community / Q000706:statistics & numerical data; D006801:Humans; D017053:Infection Control / Q000379:methods; D016015:Logistic Models; D008297:Male; D008480:Mediastinitis / Q000453:epidemiology / Q000382:microbiology; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D013030:Spain / Q000453:epidemiology; D013203:Staphylococcal Infections / Q000453:epidemiology*; D013212:Staphylococcus epidermidis / Q000302:isolation & purification*; D013530:Surgical Wound Infection / Q000453:epidemiology* / Q000382:microbiology; D013997:Time Factors