title: Healthcare-associated Staphylococcus aureus bacteremia and the risk for methicillin resistance: is the Centers for Disease Control and Prevention definition for community-acquired bacteremia still appropriate?
abstract: OBJECTIVE
  To evaluate a new classification for bloodstream infections that differentiates hospital acquired, healthcare associated, and community acquired in patients with blood cultures positive for Staphylococcus aureus.
  
  
  METHODS
  Prospective, observational study.
  
  
  METHODS
  Three tertiary-care, university-affiliated hospitals in Dublin, Ireland, and Strasbourg, France.
  
  
  METHODS
  Two hundred thirty consecutive patients older than 18 years with blood cultures positive for S. aureus.
  
  
  METHODS
  S. aureus bacteremia (SAB) was defined as hospital acquired if the first positive blood culture was performed more than 48 hours after admission. Other SABs were classified as healthcare associated or community acquired according to the definition proposed by Friedman et al. When available, strains of methicillin-resistant Staphylococcus aureus (MRSA) were analyzed by pulsed-field gel electrophoresis (PFGE).
  
  
  RESULTS
  Eighty-two patients were considered as having community-acquired bacteremia according to the Centers for Disease Control and Prevention (CDC) classification. Of these 82 patients, 56% (46) had healthcare-associated SAB. MRSA prevalence was similar in patients with hospital-acquired and healthcare-associated SAB (41% vs 33%; P > .05), but significantly lower in the group with community-acquired SAB (11%; P < .03). PFGE of MRSA strains showed that most community-acquired and healthcare-associated MRSA strains were similar to hospital-acquired MRSA strains. On multivariate analysis, Friedman's classification was more effective than the CDC classification for predicting MRSA.
  
  
  CONCLUSIONS
  These results support the call for a new classification for community-acquired bacteremia that would account for healthcare received outside the hospital by patients with SAB.
authors.affiliation: Service des Maladies Infectieuses et Tropicales, Hôtel-Dieu, Clermont-Ferrand, France. olivier.lesens@wanadoo.fr
authors.forename: Olivier
authors.initials: O
authors.lastname: Lesens
authors.forename: Yves
authors.initials: Y
authors.lastname: Hansmann
authors.forename: Eimar
authors.initials: E
authors.lastname: Brannigan
authors.forename: Susan
authors.initials: S
authors.lastname: Hopkins
authors.forename: Pierre
authors.initials: P
authors.lastname: Meyer
authors.forename: Brian
authors.initials: B
authors.lastname: O'Connel
authors.forename: Gilles
authors.initials: G
authors.lastname: Prévost
authors.forename: Colm
authors.initials: C
authors.lastname: Bergin
authors.forename: Daniel
authors.initials: D
authors.lastname: Christmann
mesh_terms: D000368:Aged; D016470:Bacteremia / Q000145:classification* / Q000517:prevention & control; D002487:Centers for Disease Control and Prevention, U.S.; D017714:Community-Acquired Infections / Q000145:classification* / Q000517:prevention & control; D003428:Cross Infection / Q000145:classification* / Q000517:prevention & control; D016521:Electrophoresis, Gel, Pulsed-Field; D005260:Female; D006801:Humans; D017053:Infection Control / Q000379:methods / Q000592:standards*; D016015:Logistic Models; D008297:Male; D016106:Methicillin Resistance; D008875:Middle Aged; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000517:prevention & control*; D013211:Staphylococcus aureus / Q000145:classification* / Q000302:isolation & purification; D014481:United States