title: Outbreak of methicillin-resistant Staphylococcus aureus colonization and infection in a neonatal intensive care unit epidemiologically linked to a healthcare worker with chronic otitis.
abstract: OBJECTIVE
  To describe the investigation and interventions necessary to contain an outbreak of methicillin-resistant Staphylococcus aureus (MRSA) colonization and infection in a neonatal intensive care unit (NICU).
  
  
  METHODS
  Retrospective case finding that involved prospective performance of surveillance cultures for detection of MRSA and molecular typing of MRSA by repetitive-sequence polymerase chain reaction (rep-PCR).
  
  
  METHODS
  Level III NICU in a tertiary care center.
  
  
  METHODS
  Three neonates in a NICU were identified with MRSA bloodstream infection on April 16, 2004. A point prevalence survey identified 6 additional colonized neonates (attack rate, 75% [9 of 12 neonates]). The outbreak strain was phenotypically unusual.
  
  
  METHODS
  Cohorting and mupirocin therapy were initiated for neonates who had acquired MRSA during the outbreak. Contact precautions were introduced in the NICU, and healthcare workers (HCWs) were retrained in cleaning and disinfection procedures and hand hygiene. Noncolonized neonates and newly admitted patients had surveillance cultures performed 3 times per week.
  
  
  RESULTS
  Two new colonized neonates were identified 1 month later. HCW X, who had worked in the NICU since June 2003, was identified as having chronic otitis. MRSA was isolated from cultures of swab specimens from HCW X's ear canal and nares. HCW X was epidemiologically linked to the outbreak. Molecular typing (by rep-PCR) confirmed that the isolates from HCW X and from the neonates were more than 90% similar. Retrospective review of NICU isolates revealed that the outbreak strain was initially cultured from a neonate 2 months after HCW X began working on the unit. The epidemic strain was eradicated after removing HCW X from patient care in the NICU.
  
  
  CONCLUSIONS
  An outbreak of MRSA colonization and infection in a NICU was epidemiologically linked to a HCW with chronic otitis externa and nasal colonization with MRSA. Eradication was not achieved until removal of HCW X from the NICU. Routine surveillance for MRSA may have allowed earlier recognition of the outbreak and is now standard practice in our NICU.
authors.affiliation: Department of Infection Control and Epidemiology, Division of Nursing, The Cleveland Clinic, Cleveland, OH 44195, USA. Bertinm@ccf.org
authors.forename: Mary L
authors.initials: ML
authors.lastname: Bertin
authors.forename: Joan
authors.initials: J
authors.lastname: Vinski
authors.forename: Steven
authors.initials: S
authors.lastname: Schmitt
authors.forename: Camille
authors.initials: C
authors.lastname: Sabella
authors.forename: Lara
authors.initials: L
authors.lastname: Danziger-Isakov
authors.forename: Michael
authors.initials: M
authors.lastname: McHugh
authors.forename: Gary W
authors.initials: GW
authors.lastname: Procop
authors.forename: Geraldine
authors.initials: G
authors.lastname: Hall
authors.forename: Steven M
authors.initials: SM
authors.lastname: Gordon
authors.forename: Johanna
authors.initials: J
authors.lastname: Goldfarb
mesh_terms: D016470:Bacteremia / Q000382:microbiology; D002908:Chronic Disease; D004196:Disease Outbreaks; D005260:Female; D006282:Health Personnel; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D017053:Infection Control / Q000379:methods; D017757:Infectious Disease Transmission, Professional-to-Patient; D007363:Intensive Care Units, Neonatal; D008297:Male; D016106:Methicillin Resistance; D009668:Nose Diseases / Q000150:complications* / Q000382:microbiology; D009820:Ohio; D010032:Otitis Externa / Q000150:complications* / Q000382:microbiology; D016133:Polymerase Chain Reaction; D011159:Population Surveillance; D011446:Prospective Studies; D012189:Retrospective Studies; D013203:Staphylococcal Infections / Q000150:complications / Q000635:transmission*; D013211:Staphylococcus aureus / Q000302:isolation & purification