Efficiency of cleaning and disinfection of surfaces: correlation between assessment methods

ABSTRACT Objective: to assess the correlation among the ATP-bioluminescence assay, visual inspection and microbiological culture in monitoring the efficiency of cleaning and disinfection (C&D) of high-touch clinical surfaces (HTCS) in a walk-in emergency care unit. Method: a prospective and comparative study was carried out from March to June 2015, in which five HTCS were sampled before and after C&D by means of the three methods. The HTCS were considered dirty when dust, waste, humidity and stains were detected in visual inspection; when ≥2.5 colony forming units per cm2 were found in culture; when ≥5 relative light units per cm2 were found at the ATP-bioluminescence assay. Results: 720 analyses were performed, 240 per method. The overall rates of clean surfaces per visual inspection, culture and ATP-bioluminescence assay were 8.3%, 20.8% and 44.2% before C&D, and 92.5%, 50% and 84.2% after C&D, respectively (p<0.001). There were only occasional statistically significant relationships between methods. Conclusion: the methods did not present a good correlation, neither quantitative nor qualitatively.

摘要
目的：评估ATP生物发光法（ATP-bioluminescence assay）、目视检查法与微生物培养法在监测急诊留观病房高频接触临床表面（high-touch clinical surfaces, HTCS）清洁消毒（cleaning and disinfection, C&D）效率中的相关性。
方法：本研究于2015年3月至6月开展一项前瞻性对照研究，选取5处高频接触临床表面，在实施清洁消毒前后分别采用上述三种方法进行采样检测。污染判定标准如下：目视检查发现灰尘、废弃物、潮湿痕迹或污渍即判定为污染；微生物培养法检测每平方厘米菌落形成单位（colony forming units, CFU）≥2.5即判定为污染；ATP生物发光法检测每平方厘米相对光单位（relative light units, RLU）≥5即判定为污染。
结果：本研究共完成720项检测，每种方法各240项。清洁消毒前，目视检查法、微生物培养法及ATP生物发光法判定的表面清洁率分别为8.3%、20.8%及44.2%；清洁消毒后则分别为92.5%、50%及84.2%，组间差异均具有统计学意义（p<0.001）。三种检测方法间仅存在零星的统计学显著相关性。
结论：三种检测方法无论是定量还是定性分析均未表现出良好的相关性。