S1081 Evaluation of Abbreviated HLD Protocols for Duodenoscopes With Disposable Tips

Abstract

Introduction: Recent observational studies suggest that duodenoscopes with disposable tips have lower rates of bacterial contamination compared to fully reusable duodenoscopes. However, it is unclear if the reprocessing of duodenoscopes with disposable tips can be abbreviated without compromising disinfection efficacy. We evaluated rates of duodenoscope bacterial growth after abbreviated disinfection protocols. Methods: We conducted a two-phase prospective observational study utilizing an abbreviated protocol for the disinfection of Pentax Medical ED34-i10T2 duodenoscopes with disposable tips. Phase 1 (P1), conducted from October 2021 to March 2022, used an abbreviated protocol of one manual wash (MW) prior to one cycle of high-level disinfection (HLD). Phase 2 (P2) was conducted from April to May 2022 and samples were obtained after two MWs and one HLD. Each duodenoscope was sampled in 4 locations per Figure. Samples were plated on routine medias for enteric pathogens including Clostridium difficile and Enterococcus spp. Antibiotic resistance was assessed via PCR for Vancomycin-resistant Enterococcus (VRE). One-sided Fisher’s exact test was done to identify differences in bacterial growth at each sample site in both phases. Contamination was defined by >100 CFU raw growth and >1 CFU C difficile and VRE. Results: P1: 46 duodenoscopes were sampled resulting in 184 sample events. 8 of 46 duodenoscopes had raw growth. 4 grew VRE. None grew C difficile. P2: 25 duodenoscopes were sampled resulting in 100 sample events. 2 of 25 duodenoscopes had raw growth. 4 grew VRE. None grew C difficile. P1 vs P2: There were no significant differences in total bacterial or VRE presence for all sample sites. For sites 2 and 3 in phase 2, the 95% confidence interval for the rate of contamination after two MW was 0.1% to 20.4%. This was higher than the CI limits for the rate of contamination in phase 1 (site 2 95% CI 0%, 7.7%; site 3 95% CI 0.1%, 11.5%). (Figure) Conclusion: In our study, one MW did not grow significantly more bacteria compared with two MW prior to HLD. This suggests that two MW may not be superior to one MW in achieving HLD in duodenoscopes with disposable tips. Duodenoscopes with disposable tips have lower bacterial contamination rates compared to prior FDA data1 on fully reusable duodenoscopes. Our data provide impetus for larger studies of abbreviated HLD protocols. (Table). 1 522 postmarket surveillance studies database: pilot phase (phase 1) of the Sampling and Culturing Study for Pentax. accessdata.fda.gov. 2020.Figure 1.: Sample locations: 1) The elevator tab, 2) instrument channel distal opening, 3) composite duodenoscope tip, and 4) the instrument channel. Samples 1-3 were collected with flocked swabs. The 4th was collected by flushing 25 mL of neutralizing buffer through the instrument channel, then scrubbing the channel with a brush, followed by another 25mL flush. The 50mL eluent was vacuum filtered through a 0.22-micron filter and plated on TSA. Duodenoscope serial numbers were recorded and one duodenoscope grew VRE in Phase 1 and Phase 2. Table 1. - Comparison of Contamination Rates by Sample Site in Phase 1 versus Phase 2 Phase 1 Phase 2 P1 vs. P2 (N=46) 95% CI (N=25) 95% CI p-value Raw Sample Presence ( >100 CFU) Site 1 0 (0%) 0 (0%) -- (0%, 7.7%) (0%, 13.7%) Site 2 0 (0%) 1 (4.0%) 0.35 (0%, 7.7%) (0.1%, 20.4%) Site 3 1 (2.2%) 1 (4.0%) 0.58 (0.1%, 11.5%) (0.1%, 20.4%) Site 4 7 (15.2%) 0 (0%) 1.00 (6.3%, 28.9%) (0%, 13.7%) Raw Sample Enterococcus Presence ( >1 CFU) Site 1 2 (4.3%) 1 (4.0%) 0.734 (0.5%, 14.8%) (0.1%, 20.4%) Site 2 2 (4.3%) 2 (8.0%) 0.441 (0.5%, 14.8%) (1.0%, 26.0%) Site 3 2 (4.3%) 2 (8.0%) 0.441 (0.5%, 14.8%) (1.0%, 26.0%) Site 4 0 (0%) 0 (0%) -- (0%, 7.7%) (0%, 13.7%) Raw Sample C. difficile Presence ( >1 CFU) Site 1 0 (0%) 0 (0%) -- (0%, 7.7%) (0%, 13.7%) Site 2 0 (0%) 0 (0%) -- (0%, 7.7%) (0%, 13.7%) Site 3 0 (0%) 0 (0%) -- (0%, 7.7%) (0%, 13.7%) Site 4 0 (0%) 0 (0%) -- (0%, 7.7%) (0%, 13.7%)