title: Comparing visual inspection, aerobic colony counts, and adenosine triphosphate bioluminescence assay for evaluating surface cleanliness at a medical center.
abstract: BACKGROUND
  Environmental cleaning is essential in reducing microbial colonization and health care-associated infections in hospitals. However, there is no consensus for the standard method to assess hospital cleanliness, and comparisons of newer methodology, such as adenosine triphosphate bioluminescence assay, with the traditional methods are limited.
  
  
  METHODS
  A prospective study was conducted at a medical center between January 2013 and August 2013. In each selected room, 10-12 high-touch surfaces were sampled before and after terminal cleaning. The adequacy of cleaning was evaluated by visual inspection, aerobic colony counts (ACCs), and adenosine triphosphate (ATP) bioluminescence assay.
  
  
  RESULTS
  Eighty-five environmental surfaces from 8 rooms were evaluated by all 3 methods. The overall inadequacy defined by visual inspection, ACC, and ATP level was 11.8%, 20.0%, and 50.6% before cleaning and 4.7%, 5.9%, 21.2% after cleaning, respectively. A correlation between the ACC and ATP was found (r = 0.285, P < .001) using log10 values. Using ACCs <2.5 colony forming units/cm(2) as the cutoff for cleanliness, the ATP assay had better sensitivity than visual inspection (63.6% vs 27.3%). The receiver operating characteristics of the ATP assay indicated that the optimal ATP cutoff value was estimated to be 5.57 relative light units/cm(2).
  
  
  CONCLUSIONS
  ATP bioluminescence assay is a sensitive and rapid tool in evaluating the quality of terminal cleaning. We emphasize the value of using a quantitative method to monitor environmental cleaning at hospitals.
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, Taipei City, Taiwan; Department of Internal Medicine, Hsin-Chu Branch, National Taiwan University Hospital, Hsin-Chu County, Taiwan.
authors.forename: Yu-Shan
authors.initials: YS
authors.lastname: Huang
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, Taipei City, Taiwan; Infection Control Center, National Taiwan University Hospital, Taipei City, Taiwan.
authors.forename: Yee-Chun
authors.initials: YC
authors.lastname: Chen
authors.affiliation: Infection Control Center, National Taiwan University Hospital, Taipei City, Taiwan.
authors.forename: Mei-Ling
authors.initials: ML
authors.lastname: Chen
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, Taipei City, Taiwan; Department of Internal Medicine, Hsin-Chu Branch, National Taiwan University Hospital, Hsin-Chu County, Taiwan.
authors.forename: Aristine
authors.initials: A
authors.lastname: Cheng
authors.affiliation: Infection Control Center, National Taiwan University Hospital, Taipei City, Taiwan.
authors.forename: I-Chen
authors.initials: IC
authors.lastname: Hung
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, Taipei City, Taiwan; Infection Control Center, National Taiwan University Hospital, Taipei City, Taiwan.
authors.forename: Jann-Tay
authors.initials: JT
authors.lastname: Wang
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, Taipei City, Taiwan; Infection Control Center, National Taiwan University Hospital, Taipei City, Taiwan. Electronic address: whsheng@ntu.edu.tw.
authors.forename: Wang-Huei
authors.initials: WH
authors.lastname: Sheng
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, Taipei City, Taiwan; College of Medicine, National Taiwan University, Taipei City, Taiwan.
authors.forename: Shan-Chwen
authors.initials: SC
authors.lastname: Chang
mesh_terms: D000046:Academic Medical Centers; D000255:Adenosine Triphosphate / Q000032:analysis*; D015169:Colony Count, Microbial; D004203:Disinfection / Q000379:methods*; D004783:Environmental Microbiology; D006785:Hospitals, University; D006801:Humans; D017053:Infection Control / Q000379:methods*; D008163:Luminescent Measurements; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013499:Surface Properties; D013997:Time Factors
chemical_list: D000255:Adenosine Triphosphate
keywords: ATP bioluminescence assay; Environment; Hospital cleanliness