Comparison of Two Culture Methods for Use in Assessing Microbial Contamination of Duodenoscopes

Contaminated flexible endoscopes: Review of impact of channel sampling methods on culture results and recommendations for root-cause analysis

Recently, infection transmission risk associated with contaminated, patient-ready flexible endoscopes has attracted attention. Outbreaks of multidrug-resistant organisms resulting in infection and/or colonization have been particularly concerning. Recent CDC and FDA recommendations focus on reducing "exogenous" infection transmission and specifically recommend that endoscopy sites have quality systems in place for endoscope reprocessing. Another key recommendation is the culture of patient-ready endoscopes to detect contamination with organisms of concern. Remaining gaps in the guidelines include ensuring that optimal endoscope-channel sample methods are used and ensuring effective root-cause analysis and remediation when contamination is detected. In this review, we summarize the critical aspects of endoscope sample collection and present a practical approach to root-cause analysis and remedial action plans.

A Novel Flocked Swab Protocol Proves to Be an Effective Method for Culturing Elevator-Containing Endoscopes

BACKGROUND

The challenging disinfection process for the elevator mechanism on duodenoscopes and linear echoendoscopes has been identified as a source of clinically significant bacterial transmission. Despite increased awareness, there continues to be a lack of definitive guidelines for bacterial culturing protocols for elevator-containing endoscopes.

AIMS

To compare two different prospective bacterial surveillance protocols for duodenoscopes and linear echoendoscopes with regard to accuracy, efficiency, and cost.

METHODS

Consecutive duodenoscopes and linear echoendoscopes used at a single tertiary care center were reprocessed following hospital and manufacturer guidelines, dried using an automatic endoscope-drying machine, and hung overnight in an upright position. Following reprocessing, culture samples were sequentially obtained from each endoscope using two methods, first, the brush protocol followed immediately by the swab protocol.

RESULTS

A total of 532 primary cultures were collected from 17 duodenoscopes and eight linear echoendoscopes. Of these, 266 cultures gathered using the brush protocol were negative, while 266 cultures gathered using the swab protocol resulted in three positive cultures (1.1%). Positive cultures showed Enterobacter cloacae and Klebsiella pneumoniae from one duodenoscope and two linear echoendoscopes. Yearly, the brush protocol amounts to approximately 520 nursing hours, and the swab protocol takes an estimated 42 nursing hours. Annually, the swab protocol could save over $26,500 and 478 nursing hours.

CONCLUSIONS

The proposed swab protocol was superior to the brush protocol when evaluating the presence of residual bacteria on elevator-containing endoscopes following reprocessing and saves cost and nursing hours.

Storage of gastrointestinal endoscopes: when is the safe time for re-use?

ABSTRACT Objectives: to identify the safe storage time for the use of flexible gastrointestinal endoscopes after high-level disinfection, as well as the defining criteria for this time. Methods: an integrative literature review was carried out in the Virtual Health Library, PubMed, Scopus, and Web of Science, considering original articles published since 2000. Results: eleven articles were selected, whose storage times ranged from 1 to 56 days, with a predominance of one to seven days (73%). Several criteria were used to define this time, predominantly the premise of efficient processing (100%), use of alcohol flush (64%), use of drying cabinets (18%), among others. Conclusions: the criteria for determining the storage time did not show a consensus for clinical practice. Expanding the discussion of this theme with the definition of the minimum necessary conditions is of fundamental importance for the reduction of risks and safety of the procedure and the patient.

A narrative review on current duodenoscope reprocessing techniques and novel developments

Duodenoscopy-associated infections occur worldwide despite strict adherence to reprocessing standards. The exact scope of the problem remains unknown because a standardized sampling protocol and uniform sampling techniques are lacking. The currently available multi-society protocol for microbial culturing by the Centers for Disease Control and Prevention, the United States Food and Drug Administration (FDA) and the American Society for Microbiology, published in 2018 is too laborious for broad clinical implementation. A more practical sampling protocol would result in increased accessibility and widespread implementation. This will aid to reduce the prevalence of duodenoscope contamination. To reduce the risk of duodenoscopy-associated pathogen transmission the FDA advised four supplemental reprocessing measures. These measures include double high-level disinfection, microbiological culturing and quarantine, ethylene oxide gas sterilization and liquid chemical sterilization. When the supplemental measures were advised in 2015 data evaluating their efficacy were sparse. Over the past five years data regarding the supplemental measures have become available that place the efficacy of the supplemental measures into context. As expected the advised supplemental measures have resulted in increased costs and reprocessing time. Unfortunately, it has also become clear that the efficacy of the supplemental measures falls short and that duodenoscope contamination remains a problem. There is a lot of research into new reprocessing methods and technical applications trying to solve the problem of duodenoscope contamination. Several promising developments such as single-use duodenoscopes, electrolyzed acidic water, and vaporized hydrogen peroxide plasma are already applied in a clinical setting.

Comparison of channel sampling methods and brush heads in surveillance culture of endoscope reprocessing: A propensity score matching and paired study

BACKGROUND

Endoscopy-related infections have caused multiple outbreaks. The importance of surveillance culture is gradually recognized, but sampling techniques are not consistent in many guidelines. It is unclear whether the Flush-Brush-Flush sampling method (FBFSM) is more sensitive than the conventional flush sampling method (CFSM) and whether different sampling brushes have different effects.

METHODS

The propensity score matching method was done with two matching ways, 1:1 nearest neighbor propensity score matching and full matching was used to analyze the surveillance culture data collected by FBFSM and CFSM. We fit a confounder-adjusted multiple generalized linear logistic regression model to estimate the marginal odds ratio (OR). A paired study was applied to compare the sampling effect of polyurethane foam (PU) head brush and polyamide (PA) head brush.

RESULT

From 2016 to 2020, 316 reprocessed endoscope samples were collected from all 59 endoscopy centers in Tianjin. About 279 (88.3%) reprocessed endoscopes met the threshold of Chinese national standards (<20 CFU/Channel). The qualified rate of reprocessed endoscopes sampling by CFSM (91.8%) and FBFSM (81.6%) was statistically different (p < 0.05). The adjusted OR by full matching for FBFSM was 7.98 (95% confidence interval: 3.35-21.78). Forty one pairs of colonoscopes, after reprocessing from 27 centers, were tested by PA and PU brushes, and no difference was found in microbial recovery.

CONCLUSION

FBFSM was confirmed to be a more sensitive sampling technique. PU and PA brushes had no significant difference in sampling effect.

Introduction to Transmission of Infection: Potential Agents Transmitted by Endoscopy

Pathogen contamination of endoscopes depends on pathogen factors, surface factors, and environmental conditions. The most common pathogens associated with transmission and infections associated with gastrointestinal endoscope contamination are Klebsiella pneumoniae, Escherichia coli, and Pseudomonas aeruginosa. Biofilm production together with disruption to device surfaces play an outsized role in the risk of contamination. Sampling schemes are limited by these factors, and further developments are needed to improve the accuracy of sampling.

Duodenoscope as a Vector for Transmission

Elevator-based endoscope-related infections from patient cross-contamination is a multifactorial problem related to device design, maintenance, and function, with additional risk incurred from a high-level disinfection process that lacks quality controls. This article reviews the historical context for these outbreaks, technical aspects of scope design contributing to this risk, and innovations in endoscope technology that have the potential to overcome these shortcomings. Also reviewed are interim solutions and the data that support use of some of these interventions. Still needed are a validated manufacturer-recommended schedule for routine duodenoscope and echoendoscope maintenance with reprocessing protocols that can be implemented in endoscopy units.

Results of duodenoscope culture and quarantine after manufacturer-recommended cleaning process

BACKGROUND AND AIMS

Outbreaks of infections transmitted by duodenoscopes have prompted changes to duodenoscope cleaning protocols. However, little is known about effectiveness of clinical cleaning practices. We present culture data after duodenoscope manufacturer-recommended high-level disinfection (HLD) and quarantine.

METHODS

Our institution adopted a combination of manufacturer-recommended cleaning with the Centers for Disease Control and Prevention-recommended culture and quarantine in 2015. Duodenoscopes (models TJF-Q180V, TJF-160, and PJF-160; Olympus, Center Valley, Penn, USA) underwent HLD according to the manufacturer's reprocessing manual protocols after use. Two culture specimens were then obtained using a sterile brush from the distal tip, including elevator mechanism, and by flushing sterile water through the working channel. Duodenoscopes were quarantined until cultures resulted. Positive cultures were defined as >10 colony-forming units (CFUs) of low-concern organisms or any CFUs of high-concern organisms according to Centers for Disease Control and Prevention recommendations. If either culture specimen was positive, the process was repeated until cultures were negative. Data were collected from December 2015 to July 2018.

RESULTS

There were 140 instances of duodenoscope cleaning with 280 specimens. Twenty-eight of 234 (12%) initial culture specimens (18% of cultured duodenoscopes) were positive. Five of 36 (14%) second cultures were positive. Two of 8 (25%) third cultures were positive. Ninety-eight percent of organisms cultured were gram positive. In 8 instances both culture methods (brushing and flush) were positive; otherwise, only 1 method was positive. In 11 instances (8%) duodenoscopes were removed from quarantine before final culture results. No patient had infections related to ERCP.

CONCLUSIONS

Eighteen percent of duodenoscopes had a positive culture after initial HLD. Only 3% were gram-negative bacteria. Repeated HLD was 86% and 75% effective at eliminating initial and repeat positive cultures, respectively. Initial HLD per manufacturer recommendations is not always effective at eliminating bacterial contamination. Additional steps are necessary to decrease risks of duodenoscope-transmitted infections.

Turbulent fluid flow is a novel closed-system sample extraction method for flexible endoscope channels of various inner diameters

OVERVIEW

Effective sample extraction from endoscope channels is crucial for monitoring manual cleaning adequacy as well as for ensuring optimal sensitivity for culture after disinfection. The objective of this study was to compare the efficacy of Turbulent Fluid Flow (TFF) to Flush (F) or Flush-Brush-Flush (FBF) methods.

MATERIALS & METHODS

Pseudomonas aeruginosa and Enterococcus faecalis in artificial test soil-2015 (ATS2015) were used as bacterial markers while protein and carbohydrate were the organic markers for biofilm formed inside 3.2-mm and 1.37-mm polytetrafluoroethylene (PTFE) channels. TFF was generated using compressed air and sterile water to provide friction for sample extraction. Extraction for biofilm coated PTFE channels as well as for colonoscope channels perfused with ATS2015 containing 108 CFU/mL P. aeruginosa, E. faecalis and Candida albicans was determined using TFF compared to FBF and F.

RESULTS

The extraction ratio for P. aeruginosa and E. faecalis from biofilm extracted by TFF compared to the positive control was significantly better than F for 1.37-mm channels (≥0.94 for both bacteria by TFF versus 0.69 to 0.72 by F for P. aeruginosa and E. faecalis, respectively) but not significantly different between TFF and FBF for 3.2-mm channels. F was also ineffective for extraction of protein and carbohydrate from 1.37-mm channels. Extraction efficacy by TFF from inoculated colonoscope channels was >98% for all test markers.

CONCLUSIONS

The novel TFF method for extraction of samples from colonoscope channels is a more effective method than the existing FBF and F methods.

Comparative Study of Microbiological Monitoring Results from Three Types of Sampling Methods after Gastrointestinal Endoscope Reprocessing

Objective

Compare the effects of three sampling methods on the microbiological monitoring results after reprocessing of gastrointestinal endoscopes, providing scientific basis for improving the monitoring quality of gastrointestinal endoscope cleaning and disinfection.

Method

Gastrointestinal endoscopes after reprocessing were selected randomly at the gastrointestinal endoscopy center of a tertiary hospital in Shanghai from October 2018 to February 2019. The endoscopes selected were all sampled in three different methods under continuous sampling and intermittent sampling respectively. Methods used includes, the biopsy channel group (Group A), the entire channel group (Group B), and the disc brush group (Group C). Then the colony forming units (CFU/piece) were counted in the laboratory.

Results

A total of 12 endoscopes were sampled by using continuous sampling approach, in which the detection rate of bacteria in disc brush group (33.3%) and entire channel group (33.3%) was higher than biopsy channel group (8.3%). Among the 12 endoscopes sampled with intermittent approach, the detection rate of bacteria from high to low was the disc brush group (50%), the entire channel group (41.7%), and the biopsy channel group (8.3%).

Conclusion

Different sampling methods will lead to the difference of microbiological culture results after reprocessing of gastrointestinal endoscope, indicating that the improved sampling method is beneficial to objectively reflect the endoscope cleaning and disinfection effect, and improve the monitoring quality of endoscope disinfection.

A Prospective, Randomized Comparison of Duodenoscope Reprocessing Surveillance Methods

Duodenoscope use in healthcare facilities has been associated with transmission of multidrug resistant pathogens between patients. To assist healthcare facilities in monitoring the quality of their duodenoscope reprocessing procedures and limit patient risk of infection, the Centers for Disease Control and Prevention (CDC) deployed voluntary interim duodenoscope sampling and culturing surveillance protocols in 2015. Though the interim methods were widely adopted, alternative surveillance protocols were developed and implemented at individual institutions. Here, we compared two sampling methods-the 2015 CDC interim protocol and an alternative protocol developed by the University of Wisconsin Hospitals and Clinics (UWHC). We hypothesized that the UWHC protocol would detect a higher incidence of bacterial contamination from reprocessed duodenoscopes. A total of 248 sampling events were performed at UWHC. The CDC protocol (n = 129 sampling events) required culturing samples collected from each duodenoscope after brushing its terminal end and flushing its lumen with sterile water. The UWHC protocol (n = 119 sampling events) required culturing samples collected from each duodenoscope after swabbing its elevator, immersing its terminal end into broth and flushing its lumen with saline. With the CDC method, 8.53% (n = 11) of the duodenoscopes sampled were positive for bacterial growth with 15 isolates recovered. Using the UWHC method, 15.13% (n = 18) of cultures were positive for bacterial growth with 20 isolates recovered. The relative risk of identifying a contaminated duodenoscope using the CDC interim method, however, was not different than when using the UWHC protocol. Mean processing time (27.35 and 5.11 minutes, p < 0.001) and total cost per sample event ($17.87 and $15.04) were lower using the UWHC method. As the UWHC protocol provides similar detection rates as the CDC protocol, the UWHC method is useful, provided the shorter processing time and lower cost to perform.

Elevating the standard of endoscope processing: Terminal sterilization of duodenoscopes using a hydrogen peroxide-ozone sterilizer

BACKGROUND

The health care community is increasingly aware of the processing challenges and infection risks associated with duodenoscopes owing to published reports of outbreaks and regulatory recalls. Studies have demonstrated that the current practices are inadequate for consistently producing patient-ready endoscopes. Alternatively, terminal sterilization would offer a greater margin of safety and potentially reduce the risk of patient infection. The purpose of this study was to evaluate the efficacy of a hydrogen peroxide-ozone sterilizer with regulatory clearance for terminal sterilization of duodenoscopes.

METHODS AND RESULTS

Validation studies were performed under laboratory simulated-use and clinical in-use conditions. The overkill method study demonstrated a reduction of at least 6-log of Geobacillus stearothermophilus spores at half-cycle, providing a sterility assurance level of 10^-6. In addition, the sterilizer achieved a 6-log reduction of G stearothermophilus in the presence of inorganic and organic soils in a simulated-use study. The clinical in-use study confirmed that the sterilizer achieved sterilization of patient-soiled duodenoscopes under actual use conditions.

CONCLUSIONS

Simulated-use and clinical in-use studies demonstrated the efficacy of a hydrogen peroxide-ozone sterilizer for terminal sterilization of duodenoscopes. This offers health care facilities a viable alternative for duodenoscope processing to enhance patient safety as part of a comprehensive infection control strategy.

Evaluation of an overnight non-culture test for detection of viable Gram-negative bacteria in endoscope channels

Background and study aims  Prevention of infection transmission from contaminated endoscopes would benefit from a rapid test that could detect low levels of viable bacteria after high level disinfection. The aim of this study was to evaluate the rapid NOW! (RN) test's ability to detect endoscope contamination. Materials and methods  The RN test kit and the accompanying fluorometer were evaluated. The manufacturer states that a fluorometer signal > 300 units is indicative of viable Gram-negative bacteria. Suspension testing of varying concentrations of Escherichia coli, Pseudomonas aeruginosa and Enterococcus faecalis were used to determine the RN test limit of detection. Simulated-use testing was done using a duodenoscope inoculated with 10 % blood containing approximately 35 CFU E. coli per channel. Samples were extracted from the duodenoscope instrument channel and tested using the manufacturer's instructions. Results  The RN test could consistently detect 10 CFU of E. coli and P. aeruginosa (fluorescent signal of 9,000 to 11,000 units) but not E. faecalis. Sensitivity and specificity for Gram-negative bacteria were 93 % and 90 %, respectively, using all of the suspensions in the study. Extraction of E. coli from an inoculated duodenoscope instrument channel repeatedly provided a positive signal (i. e. > 2,000 units). Conclusions  The RN test can reliably detect low levels of Gram-negative bacteria in suspension as well as from samples extracted from endoscope channels. These preliminary findings are encouraging but further assessment of extraction efficacy, impact of organic residuals and clinical workflow are still needed.

Inspection of endoscope instrument channels after reprocessing using a prototype borescope

BACKGROUND AND AIMS

Visual inspection of the instrument channel has been proposed as a quality assurance step during endoscope reprocessing. However, the nature and severity of findings in a broad array of endoscopes (gastroscopes, colonoscopes, duodenoscopes, and echoendoscopes) after systemic implementation of an inspection protocol remain unknown. In addition, a study using borescope inspection in upper endoscopes and colonoscopes raised concerns about persistent simethicone residue despite full reprocessing.

METHODS

A pilot inspection study using a prototype borescope (SteriCam Inspection Scope; SteriView Inc, San Rafael, Calif) was performed on routinely used endoscopes after high-level disinfection, manual forced-air dry of the instrument channel, and overnight vertical storage. Video recordings 1.5 to 2 minutes in duration were reviewed for visible moisture, debris, discoloration, scratches, channel shredding (scratches that result in strips or filaments of the channel lining protruding into the lumen), and visible evidence of biofilm or simethicone residue.

RESULTS

A total of 97 inspections of 59 endoscopes were reviewed. The most common finding was scratches, seen in 51 devices (86%). Channel shredding was found in 35 devices (59%). Intrachannel debris was identified in 22 (23%) of the 97 inspections. No moisture was seen (0%) in the 74 inspections performed after forced-air dry and overnight vertical storage compared with moisture in 5 of 18 inspections (28%) performed after storage alone. No visual evidence of biofilm or simethicone residue was discovered despite its frequent use in our unit.

CONCLUSION

Internal defects of the instrument channel appear to occur frequently. Manual forced-air drying of the channel appears to be highly effective in eliminating moisture compared with overnight hang drying alone. Video inspection of the endoscope channel may be useful to audit reprocessing performance and to identify damaged endoscopes.

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.

Duodenoscope reprocessing practice patterns in U.S. endoscopy centers: a survey study

BACKGROUND AND AIMS

After recent outbreaks of duodenoscope-related infections from multidrug-resistant organisms (MDRO), the United States Food and Drug Administration (FDA) recommended implementing 1 or more of 4 enhanced reprocessing measures in addition to updated manual cleaning methods and high-level disinfection (HLD). The implementation of these techniques in endoscopy facilities and provider opinions regarding reprocessing priorities remain unknown.

METHODS

Physicians, nurse managers, nurses, and infection control staff at endoscopy units performing ERCP in the United States were surveyed to assess current institutional practices and individual opinions regarding future reprocessing solutions.

RESULTS

A total of 249 distinct institutions participated in the survey. Of these, 223 (89.6%) implemented at least 1 of the 4 supplemental reprocessing methods after MDRO outbreaks. Overall, 63% of centers used repeat HLD, 53% performed surveillance microbiological culturing, 35% used liquid chemical sterilization, and 12% used ethylene oxide sterilization. Thirty-seven centers (15%) routinely screened patients for MDRO. Forced-air drying after reprocessing was used by 47.8% of centers. Fifty percent of individual respondents, including 58.6% of physicians, believed that redesign of the duodenoscope is the best long-term reprocessing solution. The majority (55.1%) identified efficacy to be the single most important factor in selecting a reprocessing technique.

CONCLUSIONS

Although most endoscopy centers have implemented enhanced duodenoscope reprocessing techniques, there is a large variation in practice. Most providers believe that duodenoscope redesign and identifying reprocessing techniques with maximal efficacy are the long-term priorities. Improved adherence to forced-air drying in duodenoscope reprocessing is needed.

Implementation of a systematic culturing program to monitor the efficacy of endoscope reprocessing: outcomes and costs

BACKGROUND AND AIMS

In 2015, the U.S. Food and Drug Administration and Centers for Disease Control and Prevention (CDC) issued guidance for duodenoscope culturing and reprocessing in response to outbreaks of carbapenem-resistant Enterobacteriaceae (CRE) duodenoscope-related infections. Based on this guidance, we implemented best practices for reprocessing and developed a systematic process for culturing endoscopes with elevator levers. The aim of this study is to report the outcomes and direct costs of this program.

METHODS

First, clinical microbiology data from 2011 to 2014 were reviewed retrospectively to assess for possible elevator lever-equipped endoscope-related CRE infections. Second, a program to systematically culture elevator lever-equipped endoscopes was implemented. Each week, about 25% of the inventory of elevator lever-equipped endoscopes is cultured based on the CDC guidelines. If any cultures return bacterial growth, the endoscope is quarantined pending repeat culturing. The costs of the program, including staff time and supplies, have been calculated.

RESULTS

From 2011 to 2014, none of 17 patients with documented CRE infection had undergone ERCP or endoscopic ultrasound in the previous 36 months. From June 2015 to September 2016, 285 cultures were performed. Three (1.1%) had bacterial growth, 2 with skin contaminants and 1 with an oral contaminant. The associated endoscopes were quarantined and reprocessed, and repeat cultures were negative. The total estimated cost of our program for an inventory of 20 elevator lever-equipped endoscopes was $30,429.60 per year ($1521.48 per endoscope).

CONCLUSIONS

This 16-month evaluation of a systematic endoscope culturing program identified a low rate of positive cultures after elevator lever endoscope reprocessing. All positive cultures were with non-enteric microorganisms. The program was of modest cost and identified reprocessing procedures that may have led to a low rate of positive cultures.

Sterile Reverse Osmosis Water Combined with Friction Are Optimal for Channel and Lever Cavity Sample Collection of Flexible Duodenoscopes

Introduction

Simulated-use buildup biofilm (BBF) model was used to assess various extraction fluids and friction methods to determine the optimal sample collection method for polytetrafluorethylene channels. In addition, simulated-use testing was performed for the channel and lever cavity of duodenoscopes.

Materials and methods

BBF was formed in polytetrafluorethylene channels using Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa. Sterile reverse osmosis (RO) water, and phosphate-buffered saline with and without Tween80 as well as two neutralizing broths (Letheen and Dey-Engley) were each assessed with and without friction. Neutralizer was added immediately after sample collection and samples concentrated using centrifugation. Simulated-use testing was done using TJF-Q180V and JF-140F Olympus duodenoscopes.

Results

Despite variability in the bacterial CFU in the BBF model, none of the extraction fluids tested were significantly better than RO. Borescope examination showed far less residual material when friction was part of the extraction protocol. The RO for flush-brush-flush (FBF) extraction provided significantly better recovery of E. coli (p = 0.02) from duodenoscope lever cavities compared to the CDC flush method.

Discussion and conclusion

We recommend RO with friction for FBF extraction of the channel and lever cavity of duodenoscopes. Neutralizer and sample concentration optimize recovery of viable bacteria on culture.

A Novel Protocol Obviates Endoscope Sampling for Carbapenem-Resistant Enterobacteriaceae: Experience of a Center with a Prior Outbreak

BACKGROUND

Numerous published outbreaks, including one from our institution, have described endoscope-associated transmission of multidrug-resistant organisms (MDROs). Individual centers have adopted their own protocols to address this issue, including endoscope culture and sequestration. Endoscope culturing has drawbacks and may allow residual bacteria, including MDROs, to go undetected after high-level disinfection.

AIM

To report the outcome of our novel protocol, which does not utilize endoscope culturing, to address our outbreak.

METHODS

All patients undergoing procedures with elevator-containing endoscopes were asked to permit performance of a rectal swab. All endoscopes underwent high-level disinfection according to updated manufacturer's guidance. Additionally, ethylene oxide (EtO) sterilization was done in the high-risk settings of (1) positive response to a pre-procedure risk stratification questionnaire, (2) positive or indeterminate CRE polymerase chain reaction (PCR) from rectal swab, (3) refusal to consent for PCR or questionnaire, (4) purulent cholangitis or infected pancreatic fluid collections. Two endoscopes per weekend were sterilized on a rotational basis.

RESULTS

From September 1, 2015 to April 30, 2016, 556 endoscopy sessions were performed using elevator-containing endoscopes. Prompted EtO sterilization was done on 46 (8.3%) instances, 3 from positive/indeterminate PCR tests out of 530 samples (0.6%). No CRE transmission was observed during the study period. Damage or altered performance of endoscopes related to EtO was not observed.

CONCLUSION

In this pilot study, prompted EtO sterilization in high-risk patients has thus far eliminated endoscope-associated MDRO transmission, although no CRE infections were noted throughout the institution during the study period. Further studies and a larger patient sample will be required to validate these findings.

Prospective microbiologic evaluation of the forceps elevator in closed-channel duodenoscopes after reprocessing

BACKGROUND

Endoscopes are well-known sources of bacterial transmission in health care facilities offering endoscopy services. The association between multidrug-resistant bacterial infections in patients who had undergone an endoscopic retrograde cholangiopancreatography procedure with reprocessed duodenoscopes has been much discussed. Bacterial contamination of duodenoscopes has been attributed to difficulties with reprocessing these devices, specifically the distal end of the scope, which features a movable forceps elevator. In light of a recent Food and Drug Administration warning letter to Olympus regarding their closed-channel duodenoscope model TJF-Q180V, the aim of our study was to prospectively evaluate the efficacy and safety of our current reprocessing procedures with regard to the TJF-Q180V duodenoscope models used in our hospital.

METHODS

From August 2015-March 2016, we prospectively collected microbiologic surveillance samples from 6 TJF-Q180V model duodenoscopes in routine use at the Division of Gastroenterology and Hepatology using the ESwab collection system (COPAN Diagnostics Inc, Murrieta, CA).

RESULTS

A total of 237 microbiologic samples from the forceps elevator were obtained during the survey period. None of the samples yielded microorganism growth.

CONCLUSION

These findings suggest that when following a diligent and validated reprocessing standard in accordance with manufacturer's recommendations, closed-channel endoscope models can still be used. Nevertheless, validated adaptions of current closed-channel duodenoscope models are needed to allow for simple and safe reprocessing. Furthermore, comprehensive postmarket surveillance needs to be established.

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.

Disposable Bronchoscope Model for Simulating Endoscopic Reprocessing and Surveillance Cultures

BACKGROUND Endoscope-associated infections are reported despite following proper reprocessing methods. Microbiological testing can confirm the adequacy of endoscope reprocessing. Multiple controversies related to the method and interpretation of microbiological testing cultures have arisen that make their routine performance a complex target. OBJECTIVE We conducted a pilot study using disposable bronchoscopes (DBs) to simulate different reprocessing times and soaking times and to compare high-level disinfection versus ethylene oxide sterilization. We also reviewed the time to reprocessing and duration of the procedures. METHODS Bronchoscopes were chosen because an alternative disposable scope is commercially available and because bronchoscopes are more prone to delays in processing. Disposable bronchoscopes were contaminated using a liquid bacterial suspension and were then incubated for 1-4 hours. Standard processing and high-level disinfection were performed on 36 endoscopes. Ethylene oxide sterilization was performed on 21 endoscopes. Endoscope cultures were performed using the standard "brush, flush, brush" technique. RESULTS After brushing was performed, a final water-flush culture procedure was the most effective method of detecting bacterial persistence on the disposable scopes. Klebsiella pneumoniae was the most commonly recovered organism after reprocessing. Ethylene oxide sterilization did not result in total elimination of viable bacteria. CONCLUSION Routine endoscopy cultures may be required to assess the adequacy of endoscopic processing. Infect Control Hosp Epidemiol 2017;38:136-142.

Duodenoscope-Associated Bacterial Infections: A Review and Update

OPINION STATEMENT

Physicians depend on the use of flexible endoscopes for delivery of vital care that is morbidity sparing compared to surgical alternatives. Iatrogenic infection is a well-documented complication of therapeutic endoscopy. Recent emergence of unique antimicrobial resistance patterns and molecular "fingerprinting" of bacteria harken a new era in duodenoscope-related infections which occur in spite of compliance with device manufacturer-recommended protocols for high-level disinfection (HLD). Further studies suggest that these protocols are likely inadequate. Endoscopic retrograde cholangiopancreatography (ERCP) remains critical in the provision of minimally invasive diagnostic, therapeutic, and palliative care for patients with pancreaticobiliary disease. This manuscript reviews the history of duodenoscope-related infections, current challenges to scope reprocessing, and recommendations from regulatory agencies.