Prospective assessment of the effectiveness of standard high-level disinfection for echoendoscopes

Background and Aims: Duodenoscopes have been implicated in the transmission of multidrug-resistant organisms (MDROs). Echoendoscopes could potentially transmit infection. The aim of this study was to assess the effectiveness of standard high-level disinfection (HLD) for radial and linear echoendoscopes and to compare it with that of duodenoscopes. Methods: We performed a prospective single-center study sampling echoendoscopes immediately before use, from the working channel (radial and linear echoendoscopes) and the transducer (radial echoendoscope) or elevator mechanism and transducer (linear echoendoscope). The primary outcome was the proportion of echoendoscopes with any culture showing >= 1 MDRO; secondary outcomes included bacterial growth > 0 colony forming units (CFUs) and >= 10 CFUs on either sampling location. We compared these findings with duodenoscope cultures from the previously published DISINFECTS trial. Results: During the study period, 101 echoendoscopes were sampled (n=50 radial echoendoscopes, n=51 linear echoendoscopes). No MDROs were recovered. Bacterial growth > 0 CFUs was noted in 6% and >= 10 CFUs in 3% of all echoendoscopes. There was no significant difference in growth between radial and linear echoendoscopes (P=. 4 for > 0 CFU growth; P =.6 for >= 10 CFUs growth). The proportion of transducer and/or elevator mechanism positive for bacterial growth was significantly higher in duodenoscopes as compared with echoendoscopes (P=. 02). Conclusions: After standard HLD, no echoendoscope showed MDRO growth, 6% showed > 0 CFUs, and 3% showed >= 10 CFUs bacterial growth. Bacterial growth was higher in duodenoscopes at the level of the transducer and/or elevator mechanism when compared with echoendoscopes.