Assessment of disinfection of hospital surfaces using different monitoring methods

Abstract

OBJECTIVE: to assess the efficiency of cleaning/disinfection of surfaces of an Intensive Care Unit. METHOD: descriptive-exploratory study with quantitative approach conducted over the course of four weeks. Visual inspection, bioluminescence adenosine triphosphate and microbiological indicators were used to indicate cleanliness/disinfection. Five surfaces (bed rails, bedside tables, infusion pumps, nurses' counter, and medical prescription table) were assessed before and after the use of rubbing alcohol at 70% (w/v), totaling 160 samples for each method. Non-parametric tests were used considering statistically significant differences at p<0.05. RESULTS: after the cleaning/disinfection process, 87.5, 79.4 and 87.5% of the surfaces were considered clean using the visual inspection, bioluminescence adenosine triphosphate and microbiological analyses, respectively. A statistically significant decrease was observed in the disapproval rates after the cleaning process considering the three assessment methods; the visual inspection was the least reliable. CONCLUSION: the cleaning/disinfection method was efficient in reducing microbial load and organic matter of surfaces, however, these findings require further study to clarify aspects related to the efficiency of friction, its frequency, and whether or not there is association with other inputs to achieve improved results of the cleaning/disinfection process.

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

“…The efficiency of ATPbioluminescence has been tested in many studies (3)(4)(12)(13) , and strong correlations between ACC and levels of ATP were found under specific and controlled conditions, but they were limited in healthcare environments (1,3,14) . This can be explained by the diversity of ATP measurement systems, cut-off points and surface C&D practices among the institutions/units where those studies were conducted.…”

“…Many studies have found a weak correlation between nonmicrobiological methods and ACC for the monitoring of the efficiency of C&D in HTCS (4,13,16,19) . In this study, visual inspection and ATP-bioluminescence differed from ACC qualitative results in 29.6% and 45.8% of cases, respectively.…”

“…The HTCS were sampled by visual inspection, microbiological culture and ATP-bioluminescence assay before and after C&D. The surfaces were sampled -exclusively by the authors of this study, and only once a day -right before and 10 minutes after the end of the C&D morning session (3)(4) . There was not a specific department for collection of HTCS.…”

“…Following the manufacturer's recommendation and the literature (4) , a sterile cotton swab was leaned over the tested surface until it was slightly bended, forming a 30° angle, and then rubbed in zigzag fashion. This method measures the amount of organic ATP found in the sample.…”

“…The amount of RLU is proportional to the amount of ATP, which in turn is proportional to the density of the organic material (6)(7)(8) . The surfaces were considered clean when the ATP index was <5 RLU/cm², collected from a 100 cm² surface, that is, <500 RLU/surface (3)(4)(5)9) …”