A double-reprocessing high-level disinfection protocol does not eliminate positive cultures from the elevators of duodenoscopes.

Background and study aim Duodenoscopes have been the source of serious infection, despite correct performance of high-level disinfection (HLD). This study aimed to observe the impact of performing HLD twice on the rate of positive cultures from duodenoscope elevators. Methods We performed double HLD (DHLD; i.e. complete manual cleaning followed by automated reprocessing, with the entire process repeated) and then randomly cultured the elevators of our duodenoscopes on about 30% of occasions. Results DHLD was associated with positive elevator cultures for any microorganism in 9.4% of cases, with a 0.8% rate of known pathogens (627 cultures) between May 2015 and February 2016. After February 2016, and in association with changing the precleaning fluid, as well as use of a new FDA-recommended cleaning brush, the rate of positive cultures for any microorganism after DHLD was 4.8% and 0.2% for known pathogens (420 cultures). In a third phase, characterized by a change in personnel performing DHLD and retirement of a duodenoscope with a high rate of positive cultures, the rate of positive cultures for any microorganism was 4.9% (783 cultures) and the rate of positive culture for known pathogens was 0.3 %. To our knowledge, no duodenoscope transmission of infection occurred during the study interval. Conclusions DHLD resulted in a low rate of positive cultures for known pathogens and for organisms of low pathogenic potential, but did not eliminate these, from duodenoscope elevators. Additional improvements in HLD protocols and/or duodenoscope design are needed.