title: First outbreak with MRSA in a Danish neonatal intensive care unit: risk factors and control procedures.
abstract: BACKGROUND
  The purpose of the study was to describe demographic and clinical characteristics and outbreak handling of a large methicillin-resistant Staphylococcus aureus (MRSA) outbreak in a neonatal intensive care unit (NICU) in Denmark June 25(th)-August 8(th) 2008, and to identify risk factors for MRSA transmission.
  
  
  METHODS
  Data were collected retrospectively from medical records and the Danish Neobase database. All MRSA isolates obtained from neonates, relatives and NICU health care workers (HCW) as well as environmental cultures were typed.
  
  
  RESULTS
  During the 46 day outbreak period, 102 neonates were admitted to the two neonatal wards. Ninety-nine neonates were subsequently sampled, and 32 neonates (32%) from 25 families were colonized with MRSA (spa-type t127, SCCmec V, PVL negative). Thirteen family members from 11 of those families (44%) and two of 161 HCWs (1%) were colonized with the same MRSA. No one was infected. Five environmental cultures were MRSA positive. In a multiple logistic regression analysis, nasal Continuous Positive Airway Pressure (nCPAP) treatment (p = 0.006) and Caesarean section (p = 0.016) were independent risk factors for MRSA acquisition, whereas days of exposure to MRSA was a risk factors in the unadjusted analysis (p = 0.04).
  
  
  CONCLUSIONS
  MRSA transmission occurs with high frequency in the NICU during hospitalization with unidentified MRSA neonates. Caesarean section and nCPAP treatment were identified as risk factors for MRSA colonization. The MRSA outbreak was controlled through infection control procedures.
authors.affiliation: Department of Pediatrics, Copenhagen University Hospital Glostrup, Glostrup, Denmark. benedicte.ramsing@gmail.com
authors.forename: Benedicte Grenness Utke
authors.initials: BG
authors.lastname: Ramsing
authors.forename: Magnus
authors.initials: M
authors.lastname: Arpi
authors.forename: Erik Arthur
authors.initials: EA
authors.lastname: Andersen
authors.forename: Niels
authors.initials: N
authors.lastname: Knabe
authors.forename: Dorthe
authors.initials: D
authors.lastname: Mogensen
authors.forename: Dorte
authors.initials: D
authors.lastname: Buhl
authors.forename: Henrik
authors.initials: H
authors.lastname: Westh
authors.forename: Christian
authors.initials: C
authors.lastname: Ostergaard
mesh_terms: D017714:Community-Acquired Infections / Q000453:epidemiology / Q000517:prevention & control / Q000635:transmission; D003718:Denmark / Q000453:epidemiology; D004196:Disease Outbreaks / Q000517:prevention & control* / Q000706:statistics & numerical data*; D004777:Environment; D005190:Family; D005260:Female; D006282:Health Personnel / Q000706:statistics & numerical data; D006761:Hospitals / Q000706:statistics & numerical data; D006801:Humans; D007231:Infant, Newborn; D017053:Infection Control / Q000706:statistics & numerical data*; D007363:Intensive Care Units, Neonatal / Q000706:statistics & numerical data*; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000302:isolation & purification / Q000502:physiology*; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000517:prevention & control* / Q000635:transmission