Comparison of channel sampling methods and brush heads in surveillance culture of endoscope reprocessing: A propensity score matching and paired study

Abstract

Background: Endoscopy-related infections have caused multiple outbreaks. The importance of surveillance culture is gradually recognized, but sampling techniques are not consistent in many guidelines. It is unclear whether the Flush-Brush-Flush sampling method (FBFSM) is more sensitive than the conventional flush sampling method (CFSM) and whether different sampling brushes have different effects. Methods: The propensity score matching method was done with two matching ways, 1:1 nearest neighbor propensity score matching and full matching was used to analyze the surveillance culture data collected by FBFSM and CFSM. We fit a confounder-adjusted multiple generalized linear logistic regression model to estimate the marginal odds ratio (OR). A paired study was applied to compare the sampling effect of polyurethane foam (PU) head brush and polyamide (PA) head brush. Result: From 2016 to 2020, 316 reprocessed endoscope samples were collected from all 59 endoscopy centers in Tianjin. About 279 (88.3%) reprocessed endoscopes met the threshold of Chinese national standards (<20 CFU/Channel). The qualified rate of reprocessed endoscopes sampling by CFSM (91.8%) and FBFSM (81.6%) was statistically different (p < 0.05). The adjusted OR by full matching for FBFSM was 7.98 (95% confidence interval: 3.35-21.78). Forty one pairs of colonoscopes, after reprocessing from 27 centers, were tested by PA and PU brushes, and no difference was found in microbial recovery. Conclusion: FBFSM was confirmed to be a more sensitive sampling technique. PU and PA brushes had no significant difference in sampling effect.

Evidence of transmission of New Delhi metallo-β-lactamase-producing Klebsiella pneumoniae through a gastrointestinal endoscope without an elevator channel

“…Multiple guidelines exist for sampling and routine microbiological surveillance of endoscopes and vary by frequency, methodology, and bacterial threshold required for a positive screen. 21 The current FDA/CDC/ASM guideline currently suggest the flush-brush-flush sampling method for channels with available brushes, which has shown higher sensitivity than other methods of surveillance including conventional flush sampling with sterile water or saline without a brush. 11,12,21 Beyond the sampling method, other factors such as culture media, incubation temperature and duration, and sample concentration techniques can influence the sensitivity of endoscopic surveillance.…”

“…21 The current FDA/CDC/ASM guideline currently suggest the flush-brush-flush sampling method for channels with available brushes, which has shown higher sensitivity than other methods of surveillance including conventional flush sampling with sterile water or saline without a brush. 11,12,21 Beyond the sampling method, other factors such as culture media, incubation temperature and duration, and sample concentration techniques can influence the sensitivity of endoscopic surveillance. 22 The lack of positive endoscope culture in our outbreak underscores the challenges associated with microbiologic surveillance of medical equipment.…”