title: Spread of methicillin-resistant Staphylococcus aureus in a large tertiary NICU: network analysis.
abstract: OBJECTIVE
  Methicillin-resistant Staphylococcus aureus (MRSA) colonization in NICUs increases the risk of nosocomial infection. Network analysis provides tools to examine the interactions among patients and staff members that put patients at risk of colonization.
  
  
  METHODS
  Data from MRSA surveillance cultures were combined with patient room locations, nursing assignments, and sibship information to create patient- and unit-based networks. Multivariate models were constructed to quantify the risk of incident MRSA colonization as a function of exposure to MRSA-colonized infants in these networks.
  
  
  RESULTS
  A MRSA-negative infant in the NICU simultaneously with a MRSA-positive infant had higher odds of becoming colonized when the colonized infant was a sibling, compared with an unrelated patient (odds ratio: 8.8 [95% confidence interval [CI]: 5.3-14.8]). Although knowing that a patient was MRSA-positive and was placed on contact precautions reduced the overall odds of another patient becoming colonized by 35% (95% CI: 20%-47%), having a nurse in common with that patient still increased the odds of colonization by 43% (95% CI: 14%-80%). Normalized group degree centrality, a unitwide network measure of connectedness between colonized and uncolonized patients, was a significant predictor of incident MRSA cases (odds ratio: 18.1 [95% CI: 3.6-90.0]).
  
  
  CONCLUSIONS
  Despite current infection-control strategies, patients remain at significant risk of MRSA colonization from MRSA-positive siblings and from other patients with whom they share nursing care. Strategies that minimize the frequency of staff members caring for both colonized and uncolonized infants may be beneficial in reducing the spread of MRSA colonization.
authors: Department of Neonatology, Beth Israel-Deaconess Medical Center, Boston, MA 02215, USA.
authors: Alon
authors: A
authors: Geva
authors: Sharon B
authors: SB
authors: Wright
authors: Linda M
authors: LM
authors: Baldini
authors: Jane A
authors: JA
authors: Smallcomb
authors: Charles
authors: C
authors: Safran
authors: James E
authors: JE
authors: Gray
mesh_terms: D000704:Analysis of Variance; D001900:Boston / Q000453:epidemiology; D002353:Carrier State / Q000453:epidemiology; D015331:Cohort Studies; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology; D018562:Disease Transmission, Infectious / Q000706:statistics & numerical data; D005260:Female; D006786:Hospitals, Urban; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D017053:Infection Control / Q000458:organization & administration*; D007363:Intensive Care Units, Neonatal; D007902:Length of Stay; D016015:Logistic Models; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000302:isolation & purification*; D015999:Multivariate Analysis; D020380:Needs Assessment; D018570:Risk Assessment; D013203:Staphylococcal Infections / Q000175:diagnosis / Q000453:epidemiology*