title: A prolonged outbreak of Pseudomonas aeruginosa in a neonatal intensive care unit: did staff fingernails play a role in disease transmission?
abstract: OBJECTIVE
  To describe an outbreak of Pseudomonas aeruginosa bloodstream infection (BSI) and endotracheal tube (ETT) colonization in a neonatal intensive care unit (NICU), determine risk factors for infection, and make preventive recommendations.
  
  
  METHODS
  A 15-month cohort study followed by a case-control study with an environmental survey and molecular typing of available isolates using pulsed-field gel electrophoresis.
  
  
  METHODS
  Neonates in the NICU of a university-affiliated children's hospital.
  
  
  METHODS
  Improved hand washing and restriction of use of long or artificial fingernails.
  
  
  RESULTS
  Of 439 neonates admitted during the study period, 46 (10.5%) acquired P aeruginosa; 16 (35%) of those died. Fifteen (75%) of 20 patients for whom isolates were genotyped had genotype A, and 3 (15%) had genotype B. Of 104 healthcare workers (HCWs) from whom hand cultures were obtained, P aeruginosa was isolated from three nurses. Cultures from nurses A-1 and A-2 grew genotype A, and cultures from nurse B grew genotype B. Nurse A-1 had long natural fingernails, nurse B had long artificial fingernails, and nurse A-2 had short natural fingernails. On multivariate logistic regression analysis, exposure to nurse A-1 and exposure to nurse B were each independently associated with acquiring a BSI or ETT colonization with P aeruginosa, but other variables, including exposure to nurse A-2, were not.
  
  
  CONCLUSIONS
  Epidemiological evidence demonstrated an association between acquiring P aeruginosa and exposure to two nurses. Genetic and environmental evidence supported that association and suggested, but did not prove, a possible role for long or artificial fingernails in the colonization of HCWs' hands with P aeruginosa. Requiring short natural fingernails in NICUs is a reasonable policy that might reduce the incidence of hospital-acquired infections.
authors.affiliation: Acute Disease Division, Oklahoma State Department of Health, Oklahoma City, USA.
authors.forename: R L
authors.initials: RL
authors.lastname: Moolenaar
authors.forename: J M
authors.initials: JM
authors.lastname: Crutcher
authors.forename: V H
authors.initials: VH
authors.lastname: San Joaquin
authors.forename: L V
authors.initials: LV
authors.lastname: Sewell
authors.forename: L C
authors.initials: LC
authors.lastname: Hutwagner
authors.forename: L A
authors.initials: LA
authors.lastname: Carson
authors.forename: D A
authors.initials: DA
authors.lastname: Robison
authors.forename: L M
authors.initials: LM
authors.lastname: Smithee
authors.forename: W R
authors.initials: WR
authors.lastname: Jarvis
mesh_terms: D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission*; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D004196:Disease Outbreaks / Q000706:statistics & numerical data*; D004866:Equipment Contamination / Q000706:statistics & numerical data; D005260:Female; D005838:Genotype; D006801:Humans; D007231:Infant, Newborn; D017053:Infection Control; D017757:Infectious Disease Transmission, Professional-to-Patient / Q000706:statistics & numerical data*; D007363:Intensive Care Units, Neonatal / Q000706:statistics & numerical data*; D007442:Intubation, Intratracheal / Q000009:adverse effects / Q000295:instrumentation; D016015:Logistic Models; D008297:Male; D009262:Nails / Q000382:microbiology*; D009741:Nursing Staff, Hospital / Q000706:statistics & numerical data*; D009825:Oklahoma / Q000453:epidemiology; D011552:Pseudomonas Infections / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission*; D011550:Pseudomonas aeruginosa / Q000145:classification / Q000235:genetics; D012189:Retrospective Studies; D012307:Risk Factors; D012703:Serotyping; D000078329:Workforce
chemical_list: D004269:DNA, Bacterial