Evaluating the risk of duodenoscope-associated colonization and duodenoscope-associated infection: a prospective observational study

Abstract

Background: The risk of duodenoscope-associated colonization (DAC) and infection (DAI) after endoscopic retrograde cholangiopancreatography (ERCP) with a contaminated duodenoscope remains unknown. Determining the incidence of these events is crucial for developing prevention strategies. Aim: To assess the incidence of DAC and DAI. Methods: This prospective observational study included adult patients who underwent ERCP from January 2022 to December 2023. Duodenoscopes were sampled prior to each procedure. Contamination was defined as the presence of micro-organisms of gut or oral origin (MGO). Post ERCP, upon availability of culture results, patients exposed to contaminated duodenoscopes were asked to provide a stool sample and were followed for six months. Micro-organisms isolated from patient samples and clinical cultures were compared with those found in the duodenoscopes. Whole-genome sequencing (WGS) was used to confirm DAC or DAI. Findings: Among 341 ERCP patients, 73 (21.4%) procedures involved MGO-contaminated duodenoscopes. No duodenoscope-associated outbreaks occurred during the study. Stool samples were returned by 45 of the 73 patients (61.6%). Additionally, 80 MGOs from clinical cultures and 37 residual samples were stored. WGS was performed on eight duodenoscope–patient micro-organism pairs from six patients. No DAC or DAI cases were detected. Conclusion: In a non-outbreak setting, supported by monthly routine microbiological surveillance and a quarantine protocol for duodenoscopes, the risk of DAC and DAI appears low. These findings suggest limited value in intensive patient surveillance for DACs/DAIs. Further research is warranted to confirm these results and address knowledge gaps regarding risk factors for DACs and DAIs.