D0437 - Assessment of Pathogenic Enteric Flora Contaminating Novel Duodenoscopes With Disposable Tips

Tuesday, October 25, 2022

10:00 AM – 12:00 PM ET

Location: Crown Ballroom

Presenting Author(s)

SM

Sriya Muralidharan, MD

Duke University
Durham, NC

Award: Presidential Poster Award

Sriya Muralidharan, MD¹, Alice Parish, MSPH¹, Donna Niedzwiecki, PhD¹, Bobby G. Warren, MS¹, HannahSofia Brown, MD¹, Fahad S. Mohammed, BS¹, Aaron Barrett, BS², Amanda Graves, BS, MPH¹, Carly King, ¹, Carlos Triplin, CER, CRCST¹, Jessica Seidelman, MD, MPH¹, Becky Smith, MD³, Darin Dufault, MD³
¹Duke University, Durham, NC; ²Duke Health, Cary, NC; ³Duke University Health System, Durham, NC

Introduction: The FDA has advised that endoscopy units use duodenoscopes with disposable components to minimize the risk of duodenoscope-associated infections. Data are emerging on the effectiveness of disposable tips in preventing contamination of the duodenoscope with high-risk organisms. We hypothesize that disposable tips will not eliminate high-risk bacterial contamination.

Methods:

We conducted a prospective observational study from October 2021 to March 2022 to speciate and quantify the bacterial contamination rate of 46 Pentax Medical ED34-i10T2 duodenoscopes with disposable tips. After disposal of the tip, the duodenoscope was cultured after one manual wash (MW) and one cycle of high-level disinfection (HLD) in an automated endoscope re-processor, and then again after two MW and an additional cycle of HLD.

Each duodenoscope was sampled in 4 locations after the first MW-HLD cycle and the second: 1) elevator tab, 2) instrument channel distal opening, 3) composite duodenoscope tip, 4) instrument channel (Figure 1).

Bacterial pathogenicity was classified by the FDA1 as high-concern (any CFU) and low/moderate-concern organisms ( >100 CFU). Clostridium difficile and Enterococcus faecalis were classified as high-concern organisms. We compared contamination rates to historical data from the FDA surveillance study of Pentax reusable duodenoscopes that demonstrated contamination rates of 6.0% high-concern organisms and 8.2% low/moderate-concern organisms.

Results: 46 Duodenoscopes were sampled resulting in 368 sample events. After one MW-HLD cycle, 8 of 46 duodenoscopes remained contaminated with any organism. After the full HLD, 5 of 46 duodenoscopes remained contaminated with any organism. Low/moderate concern organisms were isolated in 2.7% of samples (95% CI 0.9%, 6.2%). High concern organisms were isolated in 0% of samples (95% CI 0%, 2.0%).

Discussion: Compared to historical FDA data from reusable Pentax duodenoscopes, the rate of low/moderate-concern organism contamination of duodenoscopes with disposable tips was lower, and the confidence interval excluded the historical rate. The rate and confidence interval limits for high-concern organism contamination in our study were also lower than FDA data¹. Our results suggest that disposable tips decrease but do not eliminate duodenoscope bacterial contamination.
¹522 postmarket surveillance studies database: pilot phase (phase 1) of the Sampling and Culturing Study for Pentax. accessdata.fda.gov. 2020.

Figure: Each duodenoscope was sampled in 4 locations: 1) elevator tab, 2) instrument channel distal opening, 3) composite duodenoscope tip, 4) instrument channel.

Samples 1-3 were collected with flocked swabs. Swabs were plated on routine medias for relevant enteric pathogens. The 4th was collected by flushing 25mL of neutralizing buffer through the elevator 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. Antibiotic resistance was assessed via PCR. CFU and proportion of contaminated scopes were compared between MW-HLD cycles. 

Outcome	Historical Rate	Summarized Rate across all Sites (95% CI)
Raw sample total low-concern organism >100 CFU presence	8.2%	2.7% (0.9%, 6.2%)
Raw sample total high-concern organism (Enterococcus and C difficile) >1 CFU presence	6.0%	0% (0%, 2.0%)

Table: Descriptive table comparing sample rates to historical FDA reported rates of contamination

Disclosures:

Sriya Muralidharan indicated no relevant financial relationships.

Alice Parish indicated no relevant financial relationships.

Donna Niedzwiecki indicated no relevant financial relationships.

Bobby Warren indicated no relevant financial relationships.

HannahSofia Brown indicated no relevant financial relationships.

Fahad Mohammed indicated no relevant financial relationships.

Aaron Barrett indicated no relevant financial relationships.

Amanda Graves indicated no relevant financial relationships.

Carly King indicated no relevant financial relationships.

Carlos Triplin indicated no relevant financial relationships.

Jessica Seidelman indicated no relevant financial relationships.

Becky Smith indicated no relevant financial relationships.

Darin Dufault indicated no relevant financial relationships.

Sriya Muralidharan, MD¹, Alice Parish, MSPH¹, Donna Niedzwiecki, PhD¹, Bobby G. Warren, MS¹, HannahSofia Brown, MD¹, Fahad S. Mohammed, BS¹, Aaron Barrett, BS², Amanda Graves, BS, MPH¹, Carly King, ¹, Carlos Triplin, CER, CRCST¹, Jessica Seidelman, MD, MPH¹, Becky Smith, MD³, Darin Dufault, MD³. D0437 - Assessment of Pathogenic Enteric Flora Contaminating Novel Duodenoscopes With Disposable Tips, ACG 2022 Annual Scientific Meeting Abstracts. Charlotte, NC: American College of Gastroenterology.

D0437 - Assessment of Pathogenic Enteric Flora Contaminating Novel Duodenoscopes With Disposable Tips

Presenting Author(s)

D0437 - Assessment of Pathogenic Enteric Flora Contaminating Novel Duodenoscopes With Disposable Tips