A comparative assessment of contamination rates in gastrointestinal endoscope reprocessing: sterilization versus high-level disinfection

Objectives

This study aimed to evaluate the disparity in culture results between sterilization and high-level disinfection (HLD) for duodenoscopes and linear endoscopic ultrasound (EUS), and to assess the effectiveness of different bacterial contamination detection methods.

Methods

This is a prospective randomized study, including duodenoscopes and linear EUS with adenosine triphosphate bioluminescence assay values below 200 relative light units after manual cleaning which were randomly assigned to undergo either sterilization or HLD in a 1:1 ratio. Following disinfection, all endoscopes were subjected to adenosine triphosphate bioluminescence assay testing and cultures using both swab and liquid samples from endoscope channels.

Results

Totally 752 endoscopes (444 duodenoscopes and 308 linear EUS) were studied. After disinfection, the positive culture rates for the sterilization and HLD groups were 5.9% and 7.2%, respectively (p = 0.460). No significant difference in contamination rates was observed between duodenoscopes and linear EUS (5.9% and 7.5%, respectively; p = 0.379), and no significant association between contamination rates and the presence of biliary stones was seen (7.3% vs. 6.9%; p = 0.613). The detection rate of bacteria from liquid samples taken from endoscope channels was 0.5%, which was significantly lower than the swabbing method (6.0%, p < 0.001).

Conclusions

This study found no statistically significant difference in contamination rates between sterilization and HLD methods for gastrointestinal endoscope reprocessing. The type of endoscope and the presence of biliary stones did not influence the positive culture rate. The swabbing method showed significantly higher bacterial detection when compared with liquid samples.