title: Postdischarge decontamination of MRSA, VRE, and Clostridium difficile isolation rooms using 2 commercially available automated ultraviolet-C-emitting devices.
abstract: BACKGROUND
  Two ultraviolet-C (UVC)-emitting devices were evaluated for effectiveness in reducing methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), and Clostridium difficile (CD).
  
  
  METHODS
  Six surfaces in rooms previously occupied by patients with MRSA, VRE, or CD were cultured before and after cleaning and after UVC disinfection. In a parallel laboratory study, MRSA and VRE suspended in trypticase soy broth were inoculated onto stainless steel carriers in triplicate, placed in challenging room areas, subjected to UVC, and subcultured to detect growth.
  
  
  RESULTS
  Sixty-one rooms and 360 surfaces were assessed. Before cleaning, MRSA was found in 34.4%, VRE was found in 29.5%, and CD was found in 31.8% of rooms. Cleaning reduced MRSA-, VRE-, and CD-contaminated rooms to 27.9%, 29.5%, and 22.7%, respectively (not statistically significant). UVC disinfection further reduced MRSA-, VRE-, and CD-contaminated rooms to 3.3% (P = .0003), 4.9% (P = .0003), and 0% (P = .0736), respectively. Surface colony counts (excluding floors) decreased from 88.0 to 19.6 colony forming units (CFU) (P < .0001) after manual cleaning; UVC disinfection further reduced it to 1.3 CFU (P = .0013). In a multivariable model of the carrier study, the odds of detecting growth in broth suspensions after UVC disinfection were 7 times higher with 1 machine (odds ratio, 6.96; 95% confidence interval, 3.79-13.4) for a given organism, surface, and concentration.
  
  
  CONCLUSIONS
  UVC devices are effective adjuncts to manual cleaning but vary in their ability to disinfect high concentrations of organisms in the presence of protein.
authors.affiliation: Division of Medical Microbiology and Infection Control, Vancouver General Hospital, Vancouver, BC, Canada; Department of Pathology and Laboratory Medicine, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Titus
authors.initials: T
authors.lastname: Wong
authors.affiliation: Division of Medical Microbiology and Infection Control, Vancouver General Hospital, Vancouver, BC, Canada.
authors.forename: Tracey
authors.initials: T
authors.lastname: Woznow
authors.affiliation: Business Initiatives and Support Services, Lower Mainland Health Authorities, Vancouver, BC, Canada.
authors.forename: Mike
authors.initials: M
authors.lastname: Petrie
authors.affiliation: Quality and Patient Safety, Vancouver Coastal Health, Vancouver, BC, Canada.
authors.forename: Elena
authors.initials: E
authors.lastname: Murzello
authors.affiliation: Quality and Patient Safety, Vancouver Coastal Health, Vancouver, BC, Canada.
authors.forename: Allison
authors.initials: A
authors.lastname: Muniak
authors.affiliation: School of Business, Capilano University, North Vancouver, BC, Canada.
authors.forename: Amin
authors.initials: A
authors.lastname: Kadora
authors.affiliation: Division of Medical Microbiology and Infection Control, Vancouver General Hospital, Vancouver, BC, Canada; Department of Pathology and Laboratory Medicine, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada. Electronic address: Elizabeth.Bryce@vch.ca.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Bryce
mesh_terms: D016360:Clostridioides difficile / Q000302:isolation & purification / Q000528:radiation effects*; D003428:Cross Infection / Q000382:microbiology / Q000517:prevention & control; D004203:Disinfection / Q000379:methods*; D004783:Environmental Microbiology; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology / Q000517:prevention & control; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus / Q000302:isolation & purification / Q000528:radiation effects*; D010356:Patient Isolation; D011446:Prospective Studies; D014466:Ultraviolet Rays; D065507:Vancomycin-Resistant Enterococci / Q000302:isolation & purification / Q000528:radiation effects*
keywords: Clostridium difficile; Environmental cleaning; Methicillin-resistant Staphylococcus aureus; Ultraviolet; Ultraviolet-C; Vancomycin-resistant enterococci