Use of a Sampling Area-Adjusted Adenosine Triphosphate Bioluminescence Assay Based on Digital Image Quantification to Assess the Cleanliness of Hospital Surfaces.
Contaminated surfaces play an important role in the transmission of pathogens. We sought to establish a criterion that could indicate "cleanliness" using a sampling area-adjusted adenosine triphosphate (ATP) assay. In the first phase of the study, target surfaces were selected for swab sampling before and after daily cleaning; then, an aerobic colony count (ACC) plate assay of bacteria and antibiotic-resistant bacteria was conducted. ATP swabs were also tested, and the ATP readings were reported as relative light units (RLUs). The results of the ACC and ATP assays were adjusted according to the sampling area. During the second phase of the study, a new cleaning process employing sodium dichloroisocyanurate (NaDCC) was implemented for comparison. Using the criterion of 2.5 colony-forming units (CFU)/cm², 45% of the sampled sites were successfully cleaned during phase one of the study. During phase two, the pass rates of the surface samples (64%) were significantly improved, except under stringent (5 RLU/cm²) and lax (500 RLU) ATP criteria. Using receiver-operating characteristic curve analysis, the best cut-off point for an area-adjusted ATP level was 7.34 RLU/cm², which corresponded to culture-assay levels of <2.5 CFU/cm². An area adjustment of the ATP assay improved the degree of correlation with the ACC-assay results from weak to moderate.
Division of Infection Diseases, Department of Internal Medicine, Buddhist Tzu Chi General Hospital and Tzu Chi University; Hualien 97004, Taiwan. yuhuai@tzuchi.com.tw.
Yu-Huai
YH
Ho
Division of Infection Diseases, Department of Internal Medicine, Buddhist Tzu Chi General Hospital and Tzu Chi University; Hualien 97004, Taiwan. lihshinn_wang@tzuchi.com.tw.
Lih-Shinn
LS
Wang
Unit of Infection Control and Management, Buddhist Tzu Chi General Hospital, Hualien 97004, Taiwan. jhl7557@tzuchi.com.tw.
Hui-Li
HL
Jiang
Department and Graduate Institute of Public Health, Tzu Chi University, Hualien 97004, Taiwan. 100313038@gms.tcu.edu.tw.
Chih-Hui
CH
Chang
Department and Graduate Institute of Public Health, Tzu Chi University, Hualien 97004, Taiwan. cjhsieh@mail.tcu.edu.tw.
Chia-Jung
CJ
Hsieh
Department and Graduate Institute of Public Health, Tzu Chi University, Hualien 97004, Taiwan. 100313033@gms.tcu.edu.tw.
Dan-Chi
DC
Chang
Department and Graduate Institute of Public Health, Tzu Chi University, Hualien 97004, Taiwan. 100313039@gms.tcu.edu.tw.
Hsin-Yu
HY
Tu
Department and Graduate Institute of Public Health, Tzu Chi University, Hualien 97004, Taiwan. 100313008@gms.tcu.edu.tw.
Tan-Yun
TY
Chiu
Department of Laboratory Medicine, Buddhist Tzu Chi General Hospital, Hualien 97004, Taiwan. jhj03070@tzuchi.com.tw.
Huei-Jen
HJ
Chao
Department and Graduate Institute of Public Health, Tzu Chi University, Hualien 97004, Taiwan. tsengcc@mail.tcu.edu.tw.
Chun-Chieh
CC
Tseng
D000255:Adenosine Triphosphate / Q000032:analysis*; D001419:Bacteria / Q000302:isolation & purification*; D001681:Biological Assay; D015169:Colony Count, Microbial; D004784:Environmental Monitoring; D006761:Hospitals; D006920:Hygiene; D017053:Infection Control
D000255:Adenosine Triphosphate
adenosine triphosphate; cleanliness; infection control; relative light units