title: Successful infection control for a vancomycin-intermediate Staphylococcus aureus outbreak in an advanced emergency medical service centre.
abstract: BACKGROUND
  A vancomycin-intermediate Staphylococcus aureus (VISA) (vancomycin minimum inhibitory concentration: 4mg/L) outbreak occurred in an advanced emergency medical service centre [hereafter referred to as the intensive care unit (ICU)] between 2013 and 2014.
  
  
  OBJECTIVE
  Our objective was to evaluate the infection control measures that were successful.
  
  
  METHODS
  Seventeen VISA strains were isolated from the sputum of 15 inpatients and the skin of two inpatients. Fourteen VISA strains were recognized as colonization. However, three VISA strains were isolated from the sputum of three inpatients with pneumonia. Environmental cultures were performed and VISA strains were detected in five of 65 sites. Pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST) was performed on 21 VISA strains.
  
  
  RESULTS
  Molecular typing including PFGE and MLST showed that the patterns of 19 VISA strains were identical and those of the other two VISA strains were possibly related. This meant that a horizontal transmission of VISA strains had occurred in the ICU. In August 2013, the infection control team began interventions. However, new inpatients with VISA strains continued to appear. Therefore, in October 2013, the ICU was partially closed in order to try to prevent further horizontal transmission, and existing inpatients with the VISA strain were isolated. Although new cases quickly dissipated after the partial closure, it took approximately five months to eradicate the VISA outbreak.
  
  
  CONCLUSIONS
  Our data suggest that despite the employment of various other infection control measures, partial closure of the ICU was essential in terminating this VISA outbreak.
authors.affiliation: Department of Pharmacy, Kurume University Hospital, Kurume, Japan; Department of Infection Control and Prevention, Kurume University School of Medicine, Kurume, Japan; Division of Infection Control and Prevention, Kurume University Hospital, Kurume, Japan. Electronic address: sakai_yoshirou@kurume-u.ac.jp.
authors.forename: Y
authors.initials: Y
authors.lastname: Sakai
authors.affiliation: Department of Infection Control and Prevention, Kurume University School of Medicine, Kurume, Japan.
authors.forename: L
authors.initials: L
authors.lastname: Qin
authors.affiliation: Division of Infection Control and Prevention, Kurume University Hospital, Kurume, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Miura
authors.affiliation: Department of Infection Control and Prevention, Kurume University School of Medicine, Kurume, Japan; Division of Infection Control and Prevention, Kurume University Hospital, Kurume, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Masunaga
authors.affiliation: Department of Clinical Laboratory Medicine, Kurume University Hospital, Kurume, Japan.
authors.forename: C
authors.initials: C
authors.lastname: Tanamachi
authors.affiliation: Department of Infection Control and Prevention, Kurume University School of Medicine, Kurume, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Iwahashi
authors.affiliation: Division of Microbiology, Department of Infectious Medicine, Kurume University School of Medicine, Kurume, Fukuoka, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kida
authors.affiliation: Department of Advanced Emergency Medical Service Center, Kurume University Hospital, Kurume, Japan.
authors.forename: O
authors.initials: O
authors.lastname: Takasu
authors.affiliation: Department of Advanced Emergency Medical Service Center, Kurume University Hospital, Kurume, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Sakamoto
authors.affiliation: Department of Infection Control and Prevention, Kurume University School of Medicine, Kurume, Japan; Division of Infection Control and Prevention, Kurume University Hospital, Kurume, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Watanabe
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002353:Carrier State / Q000453:epidemiology / Q000382:microbiology; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control*; D004196:Disease Outbreaks; D018562:Disease Transmission, Infectious / Q000517:prevention & control; D016521:Electrophoresis, Gel, Pulsed-Field; D004632:Emergency Medical Services; D004783:Environmental Microbiology; D005260:Female; D006801:Humans; D017053:Infection Control / Q000379:methods*; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D058885:Multilocus Sequence Typing; D018410:Pneumonia, Bacterial / Q000453:epidemiology / Q000382:microbiology; D012867:Skin / Q000382:microbiology; D013183:Sputum / Q000382:microbiology; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control*; D013211:Staphylococcus aureus / Q000145:classification / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D020713:Vancomycin Resistance
keywords: Infection control; Multi-locus sequence typing; Outbreak; Pulsed-field gel electrophoresis; Vancomycin-intermediate Staphylococcus aureus