title: An outbreak of Pseudomonas aeruginosa pneumonia and bloodstream infection associated with intermittent otitis externa in a healthcare worker.
abstract: OBJECTIVE
  To investigate an outbreak of Pseudomonas aeruginosa pneumonia and bloodstream infection among four neonates, determine risk factors for infection, and implement preventive strategies.
  
  
  METHODS
  Retrospective case finding; prospective surveillance cultures of patients, personnel, and environmental sites; molecular typing by pulsed-field gel electrophoresis; and a matched case-control study.
  
  
  METHODS
  Neonates in the level-III neonatal intensive care unit of a tertiary-care pediatric institution.
  
  
  METHODS
  Cohorting of patients with positive results for P. aeruginosa, work restrictions for staff with positive results, implementation of an alcohol-based hand product, review of infection control policies and procedures, and closure of the unit until completion of the investigation.
  
  
  RESULTS
  Seven (4%) of 190 environmental cultures and 5 (3%) of 178 cultures of individual healthcare workers' hands grew P. aeruginosa. All four outbreak isolates and one previous bloodstream isolate were genotypically identical, as were the P. aeruginosa isolates from the hands and external auditory canal of a healthcare worker with intermittent otitis externa. Four of 5 case-patients versus 5 of 15 matched control-patients had been cared for by this healthcare worker (P = .05). The healthcare worker was treated and no further cases occurred.
  
  
  CONCLUSIONS
  These findings suggest that a healthcare worker with intermittent otitis externa may have caused this cluster of fatal P. aeruginosa infections, adding the external ear to the list of colonized body sites that may serve as a source of potentially pathogenic organisms.
authors.affiliation: Children's Hospital, Boston, Massachusetts, USA.
authors.forename: Anne
authors.initials: A
authors.lastname: Zawacki
authors.forename: Edward
authors.initials: E
authors.lastname: O'Rourke
authors.forename: Gail
authors.initials: G
authors.lastname: Potter-Bynoe
authors.forename: Ann
authors.initials: A
authors.lastname: Macone
authors.forename: Stephan
authors.initials: S
authors.lastname: Harbarth
authors.forename: Donald
authors.initials: D
authors.lastname: Goldmann
mesh_terms: D016470:Bacteremia / Q000209:etiology*; D016022:Case-Control Studies; D003428:Cross Infection; D004269:DNA, Bacterial / Q000032:analysis; D004196:Disease Outbreaks; D017809:Fatal Outcome; D006801:Humans; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases; D017757:Infectious Disease Transmission, Professional-to-Patient; D007363:Intensive Care Units, Neonatal; D008404:Massachusetts; D010032:Otitis Externa / Q000150:complications* / Q000382:microbiology*; D010564:Personnel, Hospital; D018410:Pneumonia, Bacterial / Q000209:etiology*; D011446:Prospective Studies; D011552:Pseudomonas Infections / Q000209:etiology*; D011550:Pseudomonas aeruginosa / Q000472:pathogenicity*; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D004269:DNA, Bacterial