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

Abstract

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.