A randomized trial of single versus double high-level disinfection of duodenoscopes and linear echoendoscopes using standard automated reprocessing.

BACKGROUND AND AIMS: In a pilot study, we demonstrated that current guidelines for duodenoscope and linear echoendoscope (DLE) reprocessing using a single cycle of high-level disinfection (HLD) in an automated reprocessor may be inadequate. In August 2015, the U.S. Food and Drug Administration offered double HLD as a possible response to address this concern. As a result, Providence Health and Services adopted double HLD as standard procedure for DLEs, but no rigorous clinical studies supported this practice. We undertook a quality improvement study to compare single HLD versus double HLD at 4 of our 34 hospitals. METHODS: HLD of DLE was randomized, separately in each facility, to either single HLD or double HLD on weekdays, with standard double HLD on weekends or holidays. There was 99.7% compliance with the randomization scheme. Daily qualitative surveillance cultures of dried, post-HLD DLEs were collected for 6 months (1 swab sample from the elevator mechanism and 1 combined brush sample from the suction and working channels for each encounter), and each sample was incubated for 48 hours. Positivity rates of any microbial growth and growth of high-concern pathogens (potentially pathogenic enteric flora) were compared between the 2 study arms. RESULTS: Altogether, 5850 surveillance culture specimens were obtained during 2925 encounters from the 45 DLEs in clinical use in the participating hospitals. Of these, 3052 (52.2%) were from endoscopes cleaned by double HLD. Double HLD demonstrated no benefit over single HLD because similar positivity rates were observed (all P > .05). The elevator mechanism was more frequently colonized than the biopsy channel (5.2% vs 2.9%, P < .001). Among the 224 encounters with positive growth, 140 (62.5%) recovered microbes from only the elevator mechanism specimens, 73 (32.6%) recovered microbes from only the channel specimens, and 11 (4.9%) recovered microbes from both types of specimens. Double HLD failed to improve contamination rates for either sample site at any of the 4 endoscopy facilities, although there were significant overall differences in contamination rates among the facilities (P < .001), as observed in our previous study. Only 8 high-concern pathogens were recovered from 5 DLEs, all from the elevator mechanism. Persistent growth was observed on 2 duodenoscopes. One grew Enterococcus spp (not vancomycin-resistant enterococci) on 3 occasions, and Escherichia coli was present on 2 of these occasions, 1 of which was a multidrug-resistant organism. The other grew different enteric flora on 2 specimens. CONCLUSIONS: Our prospectively randomized study, involving 4 separate endoscopy facilities and standard automated endoscope reprocessing, showed that double HLD did not reduce culture positivity rates compared with single HLD in facilities with an already low positive culture rate. Alternative risk mitigation strategies will be assessed in an ongoing effort to reduce endoscope contamination.

Surveillance of guideline practices for duodenoscope and linear echoendoscope reprocessing in a large healthcare system.

BACKGROUND AND AIMS: To assess the adequacy of currently recommended duodenoscope and linear echoendoscope (DLE) automatic endoscope reprocessing (AER) and high-level disinfection (HLD), we collected daily post-reprocessing surveillance cultures of 106 DLEs in 21 Providence and Affiliate Hospitals. METHODS: Daily qualitative surveillance of dried, post-HLD DLEs was conducted for a minimum of 30 days at each facility. Positivity rates for any microbial growth and growth of high-concern pathogens were reported. Potential effects of DLE manufacturer, age, and AER processor on culture-positivity rate were assessed. RESULTS: Microbial growth was recovered from 201 of 4032 specimens (5%) or 189 of 2238 encounters (8.4%), including 23 specimens (.6%) or 21 encounters (.9%) for a high-concern pathogen. Wide variations in culture-positivity rate were observed across facilities. No striking difference in culture-positivity rate was seen among 8 DLE models, 3 DLE manufacturers, DLE age, manual or bedside cleanser, or automatic flushing system use. However, there was suggestive evidence that Custom Ultrasonics AER (Warminster, Pa, USA) had a lower culture-positivity rate than Medivators AER (Cantel Medical Corp., Little Falls, NJ, USA) for high-concern pathogen growth (0/1079 vs 21/2735 specimens or 0/547 vs 20/1582 encounters). Two endoscopes grew intestinal flora on several occasions despite multiple HLD. No multidrug-resistant organism was detected. CONCLUSIONS: In this multicenter DLE surveillance study, microbial growth was recovered in 5.0% of specimens (8.4% of encounters), with most being environmental microbes. Enteric bacterial flora was recovered in .6% of specimens (.9% of encounters), despite compliance with 2014 U.S. guidelines and manufacturers' recommendations for cleaning and HLD process. The observed better performance of Custom Ultrasonics AER deserves further investigation.