title: Prevalence of and risk factors for methicillin-resistant Staphylococcus aureus colonization and infection among infants at a level III neonatal intensive care unit.
abstract: BACKGROUND
  Methicillin-resistant Staphylococcus aureus (MRSA) is a well-known nosocomial pathogen of neonatal intensive care unit (NICU) patients and can cause both serious infections in preterm neonates and prolonged MRSA outbreaks in NICUs.
  
  
  OBJECTIVE
  Our objectives were to determine the prevalence of and identify risk factors for MRSA colonization and infection in the NICU and the impact of an active surveillance program on MRSA in the NICU.
  
  
  METHODS
  We collected weekly nasal MRSA surveillance cultures on 2,048 infants admitted to NICU over 3 years. Data on these infants were collected retrospectively. Characteristics of MRSA colonized and infected infants were analyzed and compared.
  
  
  RESULTS
  MRSA colonization was detected in 6.74% of infants, and MRSA infection occurred in 22% of those colonized. Using clinical cultures alone, only 41 (27.5%) of 149 MRSA affected infants were identified. The majority (75%) developed MRSA infection within 17 days of colonization. For every 10-day increment in NICU stay, the odds ratio of being infected and colonized with MRSA increased by 1.32 and 1.29, respectively. Colonization was significantly associated with longer NICU stay, low birth weight, low gestational age, and multiple gestation status.
  
  
  CONCLUSIONS
  Colonization is a risk factor for infection with MRSA in NICUs. Clinical cultures underestimate MRSA affected infants in NICUs, whereas active surveillance cultures could detect MRSA affected infants earlier and limit nosocomial spread.
authors.affiliation: Division of Pediatric Infectious Diseases and Immunology, Department of Pediatrics, University of Florida College of Medicine-Jacksonville, FL 32209, USA.
authors.forename: Nizar F
authors.initials: NF
authors.lastname: Maraqa
authors.forename: Lemuel
authors.initials: L
authors.lastname: Aigbivbalu
authors.forename: Carmen
authors.initials: C
authors.lastname: Masnita-Iusan
authors.forename: Peter
authors.initials: P
authors.lastname: Wludyka
authors.forename: Zan
authors.initials: Z
authors.lastname: Shareef
authors.forename: Christine
authors.initials: C
authors.lastname: Bailey
authors.forename: Mobeen H
authors.initials: MH
authors.lastname: Rathore
mesh_terms: D002353:Carrier State / Q000453:epidemiology* / Q000382:microbiology; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D015931:Intensive Care, Neonatal; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000302:isolation & purification*; D009297:Nasal Mucosa / Q000382:microbiology; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000453:epidemiology*