270. Relationship Between ATP and Colony Counts for Monitoring of Surface Cleanliness of Intensive Care Rooms
Session: Poster Abstract Session: HAI: Environment and Device Cleaning
Thursday, October 27, 2016
Room: Poster Hall

Ensuring quality of and compliance with surface cleaning protocols in the intensive care unit (ICU) is important for controlling the transmission of pathogens. However, there is no standard method for measuring surface contamination. A prospective study was conducted in 4 countries to measure cleanliness of high-touch surfaces in ICU patient rooms using ATP, colony counts, reflective surface markers (RSM) and visual inspection, both before (Phase 1) and after educational intervention (IE) of cleaning protocols (Phase 2). Results focusing on the performance of ATP and colony counts as quality indicators are reported.


Standard cleaning procedures for ICU patient rooms were recorded for each of 4 sites in Brazil, Canada, Netherlands, and the United States. Monitoring of surface cleanliness was performed on 50 ICU rooms at each site using 3M™ CleanTrace™ ATP Surface Test (reported as relative light units [RLUs]) and microbial culture (reported as colony-forming units per square centimeter [CFUs/cm2]), and a reflective surface marker . The cleanliness pass threshold for ATP sampling was 250 RLUs and for bioburden was 2.5 CFU/cm2.

Results: The percentage of tested surfaces passing ATP and bioburden thresholds prior to discharge cleaning in Phase 1, by country, ranged from 45.2% and 64.8%, respectively, to 74.8% and 88.4%, respectively. Post-cleaning pass rates were generally higher based on bioburden measurement (range: 90.8-98.4%) than for ATP measurement (range: 24.7-91.6%). Following retraining interventions in Phase 2, the pass rates for ATP and bioburden measurements generally increased. Using the cutoffs of <250 RLU and >2.5 CFU/cm2, the discordancy rate between the measurements was 61.5%. Lowering the pass thresholds for both measures improved concordance.


Re-training and real-time feedback of ATP results had a positive effect on improving ICU room cleanliness based on measures of ATP and bioburden. The clean cutoff threshold for bioburden (2.5 CFU/cm2) is likely too high as few tested surfaces were above the threshold prior to cleaning. Lowering the cutoffs for CFU and/or RLU are shown to improve concordance between ATP and bioburden pass/fail rates.

Curtis J. Donskey, MD, Geriatric Research Education and Clinical Center, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, Michelle Alfa, Ph.D., FCCM, Medical Microbiology, St. Boniface Research Centre, University of Manitoba, Winnipeg, MB, Canada, Icaro Boszczowski, MD, Infection Control, Hospital Alemao Oswaldo Cruz, Sao Paulo, Brazil and Joost Hopman, MD, Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands


C. J. Donskey, None

M. Alfa, 3M: Consultant , Consulting fee

I. Boszczowski, 3M: Consultant , Consulting fee

J. Hopman, 3M: Consultant , Consulting fee

Findings in the abstracts are embargoed until 12:01 a.m. CDT, Wednesday Oct. 26th with the exception of research findings presented at the IDWeek press conferences.