POSTOPERATIVE SERRATIA-MARCESCENS WOUND INFECTIONS TRACED TO AN OUT-OF-HOSPITAL SOURCE

From 25 August to 28 September 1994, 7 cardiovascular surgery (CVS) pa tients at a California hospital acquired postoperative Serratia marces cens infections, and 1 died, To identify the outbreak source, a cohort study was done of all 55 adults who underwent CVS at the hospital dur ing the outbreak, Specimens from the hospital environment and from han ds of selected staff were cultured, S, marcescens isolates were compar ed using restriction-endonuclease analysis and pulsed-field gel electr ophoresis, Several risk factors for S, marcescens infection were ident ified, but hospital and hand cultures were negative, In October, a pat ient exposed to scrub nurse A (who wore artificial fingernails) and to another nurse-but not to other identified risk factors-became infecte d with the outbreak strain, Subsequent cultures from nurse A's home id entified the strain in a jar of exfoliant cream, Removal of the cream ended the outbreak, S, marcescens does not normally colonize human ski n, but artificial nails may have facilitated transmission via nurse A' s hands.