Disposable Gastrointestinal Scopes: A Systematic Review.

OBJECTIVE: Endoscopes are an essential tool in the diagnosis, screening, and treatment of gastrointestinal diseases. In 2019, the Food and Drug Administration issued a news release, recommending that duodenoscope manufacturers and health care facilities phase out fully reusable duodenoscopes with fixed endcaps in lieu of duodenoscopes that are either fully disposable or those that contain disposable endcaps. With this study, we systematically reviewed the published literature on single-use disposable gastrointestinal scopes to describe the current state of the literature and provide summary recommendations on the role of disposable gastrointestinal endoscopes. MATERIALS AND METHODS: For our inclusion criteria, we searched for studies that were published in the year 2015 and afterward. We performed a literature search in PubMed using the keywords, "disposable," "reusable," "choledochoscope," "colonoscope," "duodenoscope," "esophagoscope," "gastroscope," and "sigmoidoscope." After our review, we identified our final article set, including 13 articles relating to disposable scopes, published from 2015 to 2023. RESULTS: In this review, we show 13 articles discussing the infection rate, functionality, safety, and affordability of disposable gastrointestinal scopes in comparison to reusable gastrointestinal scopes. Of the 3 articles that discussed infection rates (by Forbes and colleagues, Ridtitid and colleagues, and Ofosu and colleagues), each demonstrated a decreased risk of infection in disposable gastrointestinal scopes. Functionality was another common theme among these articles. Six articles (by Muthusamy and colleagues, Bang and colleagues, Lisotti and colleagues, Ross and colleagues, Kang and colleagues, and Forbes and colleagues) demonstrated comparable functionality of disposable scopes to reusable scopes. The most reported functionality issue in disposable scopes was decreased camera resolution. Disposable scopes also showed comparable safety profiles compared with reusable scopes. Six articles (by Kalipershad and colleagues, Muthusamy and colleagues, Bang and colleagues, Lisotti and colleagues, Luo and colleagues, and Huynh and colleagues) showed comparable rates of AEs, whereas 1 article (by Ofosu and colleagues) demonstrated increased rates of AEs with disposable scopes. Lastly, a cost analysis was looked at in 3 of the articles. Two articles (by Larsen et al and Ross and colleagues) remarked that further research is needed to understand the cost of disposable scopes, whereas 1 article (by Kang and colleagues) showed a favorable cost analysis. CONCLUSIONS: After a review of the literature published since the 2015 Food and Drug Administration safety communication, disposable scopes have been shown to be effective in decreasing infection risks while maintaining similar safety profiles to conventional reusable scopes. However, more research is required to compare disposable and reusable scopes in terms of functionality and cost-effectiveness.

Microbiological surveillance post-reprocessing of flexible endoscopes used in digestive endoscopy: a national study.

INTRODUCTION: Microbiological surveillance of endoscopes is a safety measure for verifying the quality of reprocessing procedures and identifying contaminated devices, but duodenoscope-related outbreaks are still reported. AIM: To assess the effectiveness of duodenoscope reprocessing procedures in Italy. METHODS: Between December 2019 and April 2020, data obtained from microbiological surveillance post-reprocessing in 15 Italian endoscopy units were collected. Sampling was carried out after reprocessing or during storage in a cabinet. In keeping with international guidelines and the Italian position paper, the micro-organisms were classified as high-concern organisms (HCOs) and low-concern organisms (LCOs). FINDINGS: In total, 144 samples were collected from 51 duodenoscopes. Of these, 36.81% were contaminated: 22.92% were contaminated with HCOs and 13.89% were contaminated with LCOs [2.08% with an LCO load of 11-100 colony-forming units (CFU)/device and 0.69% with an LCO load of >100 CFU/device]. The contamination rate was 27.5% in samples collected after reprocessing, 40% in samples collected during storage in a cabinet that was compliant with EN 16442:2015 (C-I), and 100% in samples collected during storage in a cabinet that was not compliant with EN 16442:2015 (NC-I). The respective HCO rates were 15.00%, 27.27% and 66.67%. Correlation between LCO contamination and storage time was demonstrated (Spearman's rho=0.3701; P=0.0026). The Olympus duodenoscope TJFQ180V demonstrated the lowest rate of contamination (29.82%), although the contamination rate was 100% for duodenoscopes stored in an NC-I cabinet. CONCLUSION: Microbiological surveillance, along with strict adherence to reprocessing protocols, may help to detect endoscope contamination at an early stage, and reduce the risk of duodenoscope-associated infections.

Bacterial contamination and organic residue after reprocessing in duodenoscopes with disposable distal caps compared with duodenoscopes with fixed distal caps: a randomized trial.

BACKGROUND AND AIMS: Newly designed duodenoscopes with disposable distal caps have been developed for better cleaning and preprocessing to reduce the risk of bacterial contamination (BC). We compared BC and organic residue of duodenoscopes with disposable distal caps and duodenoscopes with fixed distal caps after manual cleaning and high-level disinfection (HLD). METHODS: Four hundred duodenoscopes were randomized into group A (fixed distal caps, n = 200) and group B (disposable distal caps, n = 200). After manual cleaning, samples from the elevator were submitted for culture. An adenosine triphosphate (ATP) test was performed for organic residue evaluation. Based on our previous data, ATP < 40 relative light units (RLUs) had 100% sensitivity with 100% negative predictive value to confirm no BC after reprocessing. RESULTS: After manual cleaning, group A had a higher BC rate (14% vs 7%, P = .02), a higher proportion of duodenoscopes with ATP ≥ 40 RLUs (73.5% vs 57%, P = .001), and a higher mean of ATP level (226.6 vs 82.0 RLUs, P < .001) compared with group B. After HLD, the proportion of potential BC (ATP ≥ 40 RLUs) in group A was 2.7 times higher than group B (4% vs 1.5%, P = .13). Mean ATP level after HLD in the 2 groups was significantly lower than before the HLD procedure (group A, 24.2 vs 226.6 RLUs [P < .001]; group B, 20.4 vs 82.0 RLUs [P < .001], respectively). CONCLUSIONS: After manual cleaning, duodenoscopes with disposable distal caps had significantly lower BC and organic residue than duodenoscopes with fixed distal caps. Only a few duodenoscopes from each group did not pass the ATP threshold after HLD.

Assessment of postmanual cleaning adenosine triphosphate tests to prevent the use of contaminated duodenoscopes and linear echoendoscopes: the DETECT study.

BACKGROUND AND AIMS: We investigated whether the use of postmanual cleaning adenosine triphosphate (ATP) tests lowers the number of duodenoscopes and linear echoendoscopes (DLEs) contaminated with gut flora. METHODS: In this single-center before-and-after study, DLEs were ATP tested after cleaning. During the control period, participants were blinded to ATP results: ATP-positive DLEs were not recleaned. During the intervention period, ATP-positive DLEs were recleaned. DLEs underwent microbiologic sampling after high-level disinfection (HLD) with participants blinded to culture results. RESULTS: Using 15 endoscopes of 5 different DLE types, we included 909 procedures (52% duodenoscopes, 48% linear echoendoscopes). During the intervention period, the absolute rate of contamination with gut flora was higher (16% vs 21%). The main analysis showed that contamination was less likely to occur in the intervention period (odds ratio, .32; 95% credible interval [CI], .12-.85). A secondary analysis showed that this effect was based on 1 particular duodenoscope type (estimated probability, 39% [95% CI, 18%-64%] vs 9% [95% CI, 2%-21%]), whereas no effect was seen in the other 4 DLE types. In detail, of the 4 duodenoscopes of this type, 2 had lower contamination rates (69% vs 39% and 36% vs 10%). During the control period, both these duodenoscopes had multiple episodes with ongoing contamination with the same microorganism that ended weeks before the start of the intervention period (ie, they were not terminated by ATP testing). CONCLUSIONS: Postmanual cleaning ATP tests do not reduce post-HLD gut flora contamination rates of DLEs. Hence, postcleaning ATP tests are not suited as a means for quality control of endoscope reprocessing.

Disposable duodenoscopes. Is healthcare system affordability the main hindrance?

The performance of an endoscopic procedure involves introducing an endoscope through the mouth or the anus, which may potentially lead to lethal infection. The risk increases when complex and difficult-to-clean scopes are used, as in the case of duodenoscopes. Side-viewing duodenoscopes are complex in design, with the camera and working channel exit located on one side of the endoscope's distal end, and with an elevator nail also located at this point for catheter redirection. This complex design may facilitate the presence of blind areas not easy to access for cleaning, resulting in suboptimal disinfection of the duodenoscope and therefore a higher risk of bacterial infection. This is of particular importance in particularly vulnerable patients like those who are immunosuppressed (e.g., transplanted patients) or have a malignant disease and are receiving chemotherapy. Moreover, in the era of ¨superbugs¨, like carbapenem-resistant Enterobacteriaceae, infection outbreaks related to endoscopic retrograde cholangiopancreatography (ERCP) have been reported with a significant mortality rate.

Society Guidelines-Where Is the Consensus?

With reports of ongoing duodenoscope contamination and pathogen transmission despite strict adherence to manufacturer reprocessing instructions, professional societies continue to release updated recommendations. Despite general guideline similarities, there are differences. Although adherence to guidelines does not entirely eliminate pathogen contamination or transmission, it is critical to strictly adhere to updated guidelines for maximum risk reduction. In the United States, the Food and Drug Administration and Centers for Disease Control and Prevention continue to offer updates regarding improved duodenoscope reprocessing techniques and endoscope design. This article critically analyzes currently available national and international duodenoscope reprocessing guidelines.

Performance characteristics and optimal cut-off value of triple adenylate nucleotides test versus adenosine triphosphate test as point-of-care testing for predicting inadequacy of duodenoscope reprocessing.

BACKGROUND: Adenosine triphosphate (ATP) test based on one nucleotide has been applied as point-of-care testing (POCT) for bacterial contamination in the medical and food industries. Hypothetically, testing three adenylate nucleotides (A3) may provide better detection of duodenoscope bacterial contamination than ATP test. AIM: To evaluate performance characteristics and optimal cut-off value of A3 and ATP tests in predicting bacterial contamination of duodenoscopes. METHODS: Four hundred duodenoscope samples obtained after 100 endoscopic retrograde cholangiopancreatography procedures were randomized into group A (A3 test) or B (ATP test). Samples were collected from the elevator at the four-step cleaning process of duodenoscope. We defined the new cut-off value of the test for reaching 100% negative predictive value (NPV) from our receiver operating characteristic (ROC). FINDINGS: Using the cultures from the four-step cleaning process as the reference, the areas under ROC (AUROC) were 0.83 and 0.84 for group A (N = 200) and group B (N = 200), respectively. Using the cultures from post-high-level disinfection (HLD) as the reference, the AUROC were 0.35 and 0.74 for group A (N = 50) and group B (N = 50), respectively. We investigated ATP as a POCT after HLD with a new cut-off value of 40 RLU. However, this threshold did not allow detection of low numbers of bacteria. CONCLUSION: A3 and ATP tests provide good performances in predicting bacterial contamination of duodenoscopes for the four-step cleaning process. The ATP <40 RLU is helpful as a POCT after HLD; however, the limitation of this cut-off value is its inability to detect low numbers of bacteria.

Duodenoscope-Associated Infections beyond the Elevator Channel: Alternative Causes for Difficult Reprocessing.

OBJECTIVES: Duodenoscopes have been widely used for both diagnostic and therapeutic endoscopic retrograde cholangiopancreatography (ERCP) procedures, but recently, numerous outbreaks of multidrug-resistant organisms (MDRO) infections have been reported which has led to extensive research for their possible causes. Consequently, the aim of this study is to search for possible duodenoscope surface damages that could provide an alternative and plausible source of infections. MATERIALS AND METHODS: In order to assess both outer and inner surfaces, a duodenoscope was dismantled and samples were taken from the outer resin polymer and from the air/water, elevator, and working (biopsy) channels that were characterized by FTIR, DSC, TGA, AFM, SEM techniques and the antimicrobial activity were tested. RESULTS: Alterations were noticed on both the coating and working channel polymers, with external alterations increasing progressively from the proximal sample to the distal sample near the tip of the scope. However, the results showed that the coating surface was still efficient against bacterial adhesion. Changes in surface texture and also morphological changes were shown. CONCLUSIONS: The study describes the impact of routine procedural use and reprocessing cycles on the duodenoscope, showing that these may possibly make it susceptible to bacterial contamination and MDRO biofilm formation due to difficult reprocessing of the altered surfaces.

Enhanced manual cleaning efficacy of duodenoscope in endoscopy units: Results of a multicenter comprehensive quality control program.

BACKGROUND: Multiple outbreaks from contaminated duodenoscopes have been reported since 2008. This study assessed results of a multicenter comprehensive quality control (QC) program to enhance manual cleaning efficacy of duodenoscopes in endoscopy units. METHODS: Digestive Endoscopy Society of Taiwan implemented a QC program with adenosine triphosphate (ATP) testing of patient-used duodenoscopes in 2 rounds of on-site audit in endoscopy units. ATP samples were obtained from 5 different locations of the duodenoscope after manual cleaning. Duodenoscope exceeding ATP benchmark of 200 relative light units indicated inadequate manual cleaning. RESULTS: During the first round on-site audit, 12 hospitals and 27 patient-used duodenoscopes were analyzed. Distal end outer surface (29.6%), elevator mechanism (51.9%), distal attachment cap (59.3%), elevator wire channel (37.0%), and suction biopsy channel (37.0%) were inadequately cleaned. Overall, 19 (70.4%) duodenoscopes had inadequate manual cleaning, ranging widely from 0%-100% among endoscopy units. During the follow-up on-site audit, 32 patient-used duodenoscopes were analyzed, and 6 (18.8%) had inadequate manual cleaning. CONCLUSIONS: ATP tests may provide real-time feedback on the cleaning efficacy of patient-used duodenoscopes. Implementing a comprehensive QC program could enhance the efficacy of manual cleaning in endoscopy units.

Duodenoscope-Associated Infections: Update on an Emerging Problem.

The duodenoscope is among the most complex medical instruments that undergo disinfection between patients. Transmission of infection by contaminated scopes has remained a challenge since its inception. Notable risk factors for pathogen transmission include non-adherence to disinfection guidelines, encouragement of biofilm deposition due to complex design and surface defects and contaminated automated endoscope reprocessors. The most common infections following endoscopy are endogenous infections involving the patient's own gut flora. Exogenous infections, on the other hand, are associated with contaminated scopes and can theoretically be prevented by effective reprocessing. Pseudomonas aeruginosa is currently the most common organism isolated from contaminated endoscopes. Of note, reports of multidrug-resistant duodenoscopy-associated outbreaks have surfaced recently, many of which occurred despite adequate reprocessing. The FDA and CDC currently recommend comprehensive cleaning followed with at least high-level disinfection for reprocessing of flexible GI endoscopes. Reports of duodenoscope-related outbreaks despite compliance with established guidelines have prompted professional and government bodies to revisit existing guidelines and offer supplementary recommendations for duodenoscope processing. For the purposes of this review, we identified reports of duodenoscope-associated infections from 2000 till date. For each outbreak, we noted the organisms isolated, the number of cases reported, any possible explanations of contamination, and the measures undertaken to end each outbreak. We have also attempted to present an overview of recent developments in this rapidly evolving field.

A systematic review of adenosine triphosphate as a surrogate for bacterial contamination of duodenoscopes used for endoscopic retrograde cholangiopancreatography.

BACKGROUND: Bacterial culture is the accepted standard to measure the adequacy of high-level disinfection (HLD) of duodenoscopes. Adenosine triphosphate (ATP) bioluminescence assays have been suggested as an alternative method of evaluating the quality of reprocessing. We systematically reviewed published research describing the correlation between ATP and bacterial cultures. METHODS: The primary outcome was the correlation or concordance between concomitantly sampled ATP and bacterial contamination obtained from the instrument channel and/or elevator mechanism of the duodenoscope. A secondary outcome included the reduction in ATP measurements between paired samples before and after stages of duodenoscope reprocessing. RESULTS: Ten studies were included in the analysis. Four studies reported the relationship between concomitantly sampled ATP and cultures. Three studies reported receiver operating characteristic curves (1 study additionally reported a Wilcoxon rank sum test), and 1 study reported Spearman correlation coefficients and paired dichotomous measurements of ATP and bacterial contamination. All analyses suggested a poor relationship between the 2 measures. Studies measuring ATP before and after manual cleaning and before and after HLD reported a reduction in ATP after the reprocessing stage. CONCLUSION: Current research does not support the direct substitution of ATP for bacterial culture surveillance of duodenoscopes. Serial ATP measurement may be a useful tool to evaluate the adequacy of manual cleaning and for training of endoscopic reprocessing staff.

Impact of cleaning monitoring combined with channel purge storage on elimination of Escherichia coli and environmental bacteria from duodenoscopes.

BACKGROUND AND AIMS: We aimed to determine whether monitoring of duodenoscope cleaning by rapid adenosine triphosphate (ATP) combined with channel-purge storage could eliminate high-concern microorganisms. METHODS: In a simulated-use study, suction channels, as well as lever recesses, from 2 duodenoscopes models and the unsealed elevator guidewire (EGW) channel from 1 of these 2 duodenoscopes (the other model has a sealed EGW) were perfused with ATS2015 containing approximately 8 Log10 colony-forming units (CFU)/mL of both Enterococcus faecalis and Escherichia coli. Pump-assisted cleaning was monitored by rapid ATP testing. Duodenoscopes exceeding 200 relative light units (RLUs) were recleaned. Clean duodenoscopes were processed through an automated endoscope reprocessor and then stored in a channel-purge storage cabinet for 1 to 3 days. Cultures of EGW channel and instrument channel combined with the lever recess (IC-LR) were taken after storage. The impacts of extended cleaning and alcohol flush were evaluated. RESULTS: E coli was reliably eliminated in IC-LR and EGW channels of 119 duodenoscope tests (59 with sealed EGW and 60 with nonsealed EGW). However, actionable levels of E faecalis and environmental bacteria persisted. Neither alcohol flush nor extended cleaning resulted in a reduction of actionable levels for these organisms. Identification of isolates indicated that residual organisms in duodenoscope channels were hardy Gram-positive bacteria (often spore formers) that likely originated from environmental sources. CONCLUSIONS: These data indicate that high-concern Gram-negative bacteria but not E faecalis or environmental bacteria can be reliably eliminated by use of the manufacturer's instructions for reprocessing with ATP monitoring of cleaning and channel-purge storage conditions.

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.

Randomized Comparison of 3 High-Level Disinfection and Sterilization Procedures for Duodenoscopes.

BACKGROUND AND AIMS: Duodenoscopes have been implicated in the transmission of multidrug-resistant organisms (MDRO). We compared the frequency of duodenoscope contamination with MDRO or any other bacteria after disinfection or sterilization by 3 different methods. METHODS: We performed a single-center prospective randomized study in which duodenoscopes were randomly reprocessed by standard high-level disinfection (sHLD), double high-level disinfection (dHLD), or standard high-level disinfection followed by ethylene oxide gas sterilization (HLD/ETO). Samples were collected from the elevator mechanism and working channel of each duodenoscope and cultured before use. The primary outcome was the proportion of duodenoscopes with an elevator mechanism or working channel culture showing 1 or more MDRO; secondary outcomes included the frequency of duodenoscope contamination with more than 0 and 10 or more colony-forming units (CFU) of aerobic bacterial growth on either sampling location. RESULTS: After 3 months of enrollment, the study was closed because of the futility; we did not observe sufficient events to evaluate the primary outcome. Among 541 duodenoscope culture events, 516 were included in the final analysis. No duodenoscope culture in any group was positive for MDRO. Bacterial growth of more than 0 CFU was noted in 16.1% duodenoscopes in the sHLD group, 16.0% in the dHLD group, and 22.5% in the HLD/ETO group (P = .21). Bacterial growth or 10 or more CFU was noted in 2.3% of duodenoscopes in the sHLD group, 4.1% in the dHLD group, and 4.2% in the HLD/ETO group (P = .36). MRDOs were cultured from 3.2% of pre-procedure rectal swabs and 2.5% of duodenal aspirates. CONCLUSIONS: In a comparison of duodenoscopes reprocessed by sHLD, dHLD, or HLD/ETO, we found no significant differences between groups for MDRO or bacteria contamination. Enhanced disinfection methods (dHLD or HLD/ETO) did not provide additional protection against contamination. However, insufficient events occurred to assess our primary study end-point. ClinicalTrials.gov no: NCT02611648.

Adenosine Triphosphate Quantification Correlates Poorly with Microbial Contamination of Duodenoscopes.

OBJECTIVE The aim of this study was to quantify the correlation between adenosine triphosphate (ATP) measurements and bacterial cultures from duodenoscopes for evaluation of contamination following high-level disinfection. DESIGN Duodenoscopes used for any intended endoscopic retrograde cholangiopancreatography (ERCP) procedure were included. Microbiologic and ATP data were collected concomitantly and in the same manner from ERCP duodenoscopes. SETTING A high-volume endoscopy unit at a tertiary referral acute-care facility. METHODS Duodenoscopes were sampled for ATP and bacterial contamination in a contemporaneous and highly standardized fashion using a "flush-brush-flush" method for the working channel (WC) and a dry flocked swab for the elevator mechanism (EM). Specimens were processed for any aerobic bacterial growth (colony-forming units, CFU). Growth of CFU>0 and ATP relative light unit (RLU)>0 was considered a contaminated result. Frequency of discord between among WC and EM measurements were calculated using 2×2 contingency tables. The Spearman correlation coefficient was used to calculate the relatedness of bacterial contamination and ATP as continuous measurements. RESULTS The Spearman correlation coefficient did not demonstrate significant relatedness between ATP and CFU for either a WC or EM site. Among 390 duodenoscope sampling events, ATP and CFU assessments of contamination were discordant in 82 of 390 WC measurements (21%) and 331 of 390 of EM measurements (84.9%). The EM was frequently and markedly positive by ATP measurement. CONCLUSION ATP measurements correlate poorly with a microbiologic standard assessing duodenoscope contamination, particularly for EM sampling. ATP may reflect biological material other than nonviable aerobic bacteria and may not serve as an adequate marker of bacterial contamination. Infect Control Hosp Epidemiol 2017;38:678-684.

Duodenoscope reprocessing surveillance with adenosine triphosphate testing and terminal cultures: a clinical pilot study.

BACKGROUND AND AIMS: Recent reports of infectious outbreaks linked to duodenoscopes have led to proposals for duodenoscope surveillance culturing, which has inherent limitations. We aimed to assess the feasibility of real-time adenosine triphosphate (ATP) testing after manual cleaning and its ability to predict reprocessing adequacy, as determined by terminal duodenoscope cultures. METHODS: Clinically used duodenoscopes underwent reprocessing per current guidelines. After manual cleaning, ATP samples were obtained from the elevator, within the proximal biopsy port, and by flushing of the biopsy channel. After high-level disinfection (HLD), aerobic cultures of the elevator and biopsy channel were obtained using sterile technique. Duodenoscopes with any ATP sample ≥200 relative light units underwent repeated cycles of cleaning, ATP testing, HLD, and terminal culturing. RESULTS: Twenty clinically used duodenoscopes were included; 18 underwent a second reprocessing cycle, and 6 underwent a third reprocessing cycle because of detection of high ATP. After the initial reprocessing cycle, 12 of 20 (60%) duodenoscopes had positive culture results, most commonly yielding gram-negative bacilli (GNB, n = 11 from 9 duodenoscopes), and catalase-positive gram-positive cocci (CP-GPC, n = 7 from 7 duodenoscopes), suggesting staphylococcal organisms. Ambient environmental controls also showed GNB and CP-GPC growth. The overall sensitivity and specificity of ATP testing compared with terminal cultures were 30% and 53%, respectively. CONCLUSIONS: ATP sampling appears to correlate poorly with terminal culture results and cannot be recommended as a surrogate for terminal cultures. The performance and interpretation of cultures remains complicated by the potential recovery of environmental contaminants.

Multidepartmental Response to a Duodenoscope Used on a CRE Patient: A Case Study.

Transmission of carbapenem-resistant Enterobacteriaceae (CRE) via duodenoscopes, specialized endoscopes used during endoscopic retrograde cholangiopancreatography (ERCP) procedures, has attracted media attention since early 2015. This attention has placed increasing focus on the reprocessing of duodenoscopes. Current reprocessing recommendations for these endoscopes require either high-level disinfection or ethylene oxide sterilization. While reprocessing duodenoscopes, staff at endoscopy locations within the Mercy health system perform a single high-level disinfection cycle that is preceded by two cycles of manual cleaning. The Mercy system has 37 locations for gastrointestinal endoscopic procedures and nine that can accommodate patients requiring ERCP. In early 2016, the Mercy Oklahoma City location performed an ERCP on a patient known prior to the case to be a carrier of CRE. After the case, multiple departments located in both the Oklahoma City and St. Louis facilities partnered to culture and sterilize the duodenoscope used in that case to ensure its safety for use on subsequent patients. This case study presents the situation and discusses culturing of endoscopes. In light of the evidence presented, the importance of enhanced communication and cooperation to achieve patient safety should be paramount to all other factors.

Adenosine triphosphate bioluminescence for bacteriologic surveillance and reprocessing strategies for minimizing risk of infection transmission by duodenoscopes.

BACKGROUND AND AIMS: Recent outbreaks of duodenoscope-transmitted infections underscore the importance of adequate endoscope reprocessing. Adenosine triphosphate (ATP) bioluminescence testing allows rapid evaluation of endoscopes for bacteriologic/biologic residue. In this prospective study we evaluate the utility of ATP in bacteriologic surveillance and the effects of endoscopy staff education and dual cycles of cleaning and high-level disinfection (HLD) on endoscope reprocessing. METHODS: ATP bioluminescence was measured after precleaning, manual cleaning, and HLD on rinsates from suction-biopsy channels of all endoscopes and elevator channels of duodenoscopes/linear echoendoscopes after use. ATP bioluminescence was remeasured in duodenoscopes (1) after re-education and competency testing of endoscopy staff and subsequently (2) after 2 cycles of precleaning and manual cleaning and single cycle of HLD or (3) after 2 cycles of precleaning, manual cleaning, and HLD. RESULTS: The ideal ATP bioluminescence benchmark of <200 relative light units (RLUs) after manual cleaning was achieved from suction-biopsy channel rinsates of all endoscopes, but 9 of 10 duodenoscope elevator channel rinsates failed to meet this benchmark. Re-education reduced RLUs in duodenoscope elevator channel rinsates after precleaning (23,218.0 vs 1340.5 RLUs, P < .01) and HLD (177.0 vs 12.0 RLUs, P < .01). After 2 cycles of manual cleaning/HLD, duodenoscope elevator channel RLUs achieved levels similar to sterile water, with corresponding negative cultures. CONCLUSIONS: ATP testing offers a rapid, inexpensive alternative for detection of endoscope microbial residue. Re-education of endoscopy staff and 2 cycles of cleaning and HLD decreased elevator channel RLUs to levels similar to sterile water and may therefore minimize the risk of transmission of infections by duodenoscopes.