Evaluation of High-level Disinfection Processes for Linear Endoscopic Ultrasound Scopes Following New Delhi Metallo-beta-lactamase Carbapenem-resistant Enterobacteriaceae bacteremia

Abstract

BACKGROUND A patient with New Delhi metallo-beta-lactamase (NDM) carbapenem-resistant Enterobacteriaceae (CRE) bacteremia was readmitted four days following a procedure with a linear endoscopic ultrasound scope (EUS) and duodenoscope. Prior outbreaks of CRE have been linked to the elevator mechanism in duodenoscopes. An elevator mechanism is also present in linear EUS and contributes to the complexity of cleaning and disinfection. However, EUS are not included in the FDA supplemental measures for duodenoscope reprocessing. This study aims to evaluate need for standardized cleaning and disinfection recommendations for all endoscopes with an elevator mechanism. METHODS High level disinfection (HLD) processes were evaluated via direct observation and culturing endoscopes used on the index patient. The EUS and duodenoscope were sequestered following the isolation of CRE and reprocessed prior to culture. FDA guidance for duodenoscope surveillance culturing was followed. Cultures were processed by a certified environmental testing laboratory. RESULTS Direct observation revealed differences in reprocessing frequency between duodenoscopes and EUS. Duodenoscopes underwent manual cleaning and HLD both immediately after and prior to patient use. EUS were reprocessed after use, but not immediately prior to next use. Culture results revealed no growth for the duodenoscope. The EUS grew 48 colony forming units (CFUs) of Neisseria species and 113 CFU of Rothia aeria. The EUS was reprocessed and resampled, which resulted in 1 CFU of Pseudomonas stutzeri. The EUS scope was submitted to the manufacturer for evaluation. To date, no additional case of NDM-CRE has been identified. CONCLUSIONS The elevator mechanism in linear EUS may be a source of bacterial contamination and recent EUS use should be evaluated when investigating CRE. This study demonstrates the need for standardized HLD processes for all endoscopes with elevator mechanisms. Collaboration between Gastroenterology departments and Infection Prevention is crucial to patient safety.