Adenosine Triphosphate Quantification Correlates Poorly with Microbial Contamination of Duodenoscopes

In vitro comparison of methods for sampling copper-based antimicrobial surfaces

IMPORTANCE

Self-sanitizing surfaces such as copper (Cu) are increasingly used on high-touch surfaces to prevent the spread of harmful viruses and bacteria. Being able to monitor the antimicrobial properties of Cu is fundamental in measuring its antimicrobial efficacy. Thorough investigations into reliable methods to enumerate bacteria from self-sanitizing surfaces are lacking in the literature. This study demonstrates that direct use of Petrifilm on Cu surfaces most likely revives stressed and dying bacteria, which induces increased bacterial counts. This phenomenon was not observed with indirect collection methods. Studies assessing time-kill kinetics or long-term efficacy of Cu should consider the impact of the collection method chosen.

A review of Spaulding's classification system for effective cleaning, disinfection and sterilization of reusable medical devices: Viewed through a modern-day lens that will inform and enable future sustainability

Despite advances in medicine and innovations in many underpinning fields including disease prevention and control, the Spaulding classification system, originally proposed in 1957, remains widely used for defining the disinfection and sterilization of contaminated re-usable medical devices and surgical instruments. Screening PubMed and Scopus databases using a PRISMA guiding framework generated 272 relevant publications that were used in this review. Findings revealed that there is a need to evolve how medical devices are designed, and processed by cleaning, disinfection (and/or sterilization) to mitigate patient risks, including acquiring an infection. This Spaulding Classification remains in use as it is logical, easily applied and understood by users (microbiologists, epidemiologists, manufacturers, industry) and by regulators. However, substantial changes have occurred over the past 65 years that challenge interpretation and application of this system that includes inter alia emergence of new pathogens (viruses, mycobacteria, protozoa, fungi), a greater understanding of innate and adaptive microbial tolerance to disinfection, toxicity risks, increased number of vulnerable patients and associated patient procedures, and greater complexity in design and use of medical devices. Common cited examples include endoscopes that enable non- or minimal invasive procedures but are highly sophisticated with various types of materials (polymers, electronic components etc), long narrow channels, right angle and heat-sensitive components and various accessories (e.g., values) that can be contaminated with high levels of microbial bioburden and patient tissues after use. Contaminated flexible duodenoscopes have been a source of several significant infection outbreaks, where at least 9 reported cases were caused by multidrug resistant organisms [MDROs] with no obvious breach in processing detected. Despite this, there is evidence of the lack of attention to cleaning and maintenance of these devices and associated equipment. Over the last few decades there is increasing genomic evidence of innate and adaptive resistance to chemical disinfectant methods along with adaptive tolerance to environmental stresses. To reduce these risks, it has been proposed to elevate classification of higher-risk flexible endoscopes (such as duodenoscopes) from semi-critical [contact with mucous membrane and intact skin] to critical use [contact with sterile tissue and blood] that entails a transition to using low-temperature sterilization modalities instead of routinely using high-level disinfection; thus, increasing the margin of safety for endoscope processing. This timely review addresses important issues surrounding use of the Spaulding classification system to meet modern-day needs. It specifically addresses the need for automated, robust cleaning and drying methods combined with using real-time monitoring of device processing. There is a need to understand entire end-to-end processing of devices instead of adopting silo approaches that in the future will be informed by artificial intelligence and deep-learning/machine learning. For example, combinational solutions that address the formation of complex biofilms that harbour pathogenic and opportunistic microorganisms on the surfaces of processed devices. Emerging trends are addressed including future sustainability for the medical devices sector that can be enabled via a new Quintuple Helix Hub approach that combines academia, industry, healthcare, regulators, and society to unlock real world solutions.

Microbial Adherence to Contact Lenses and Pseudomonas aeruginosa as a Model Organism for Microbial Keratitis

Microbial keratitis (MK), the infection of the cornea, is a devastating disease and the fifth leading cause of blindness and visual impairment around the world. The overwhelming majority of MK cases are linked to contact lens wear combined with factors which promote infection such as corneal abrasion, an immunocompromised state, improper contact lens use, or failing to routinely disinfect lenses after wear. Contact lens-related MK involves the adherence of microorganisms to the contact lens. Therefore, this review discusses the information currently available regarding the disease pathophysiology, the common types of microorganisms causing MK, physical and organic mechanisms of adhesion, material properties which are involved in adhesion, and current antimicrobial strategies. This review also concludes that Pseudomonas aeruginosa is a model organism for the investigation of contact lens microbial adherence due to its prevalence in MK cases, its extremely robust adhesion, antimicrobial-resistant properties, and the severity of the disease it causes.

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.

Gastrointestinal endoscope contamination rates - elevators are not only to blame: a systematic review and meta-analysis

Background and study aims  Duodenoscopes that are contaminated due to inadequate reprocessing are well-documented. However, studies have demonstrated poor reprocessing of other kinds of endoscopes as well, including echoendoscopes, gastroscopes, and colonoscopes. We estimated the contamination rate beyond the elevator of gastrointestinal endoscopes based on available data. Methods  We searched PubMed and Embase from January 1, 2010 to October 10, 2020, for studies investigating contamination rates of reprocessed gastrointestinal endoscopes. A random-effects model was used to calculate the contamination rate of patient-ready gastrointestinal endoscopes. Subgroup analyses were conducted to investigate differences among endoscope types, countries, and colony-forming unit (CFU) thresholds. Results  Twenty studies fulfilled the inclusion criteria, including 1,059 positive cultures from 7,903 samples. The total contamination rate was 19.98 % ± 0.024 (95 % confidence interval [Cl]: 15.29 %-24.68 %; I ²  = 98.6 %). The contamination rates of colonoscope and gastroscope channels were 31.95 % ± 0.084 and 28.22 % ± 0.076, respectively. Duodenoscope channels showed a contamination rate of 14.41 % ± 0.029. The contamination rates among studies conducted in North America and Europe were 6.01 % ± 0.011 and 18.16% ± 0.053 %, respectively. The contamination rate among studies using a CFU threshold > 20 showed contamination of 30.36 % ± 0.094, whereas studies using a CFU threshold < 20 showed a contamination rate of 11 % ± 0.026. Conclusions  On average, 19.98 % of reprocessed gastrointestinal endoscopes may be contaminated when used in patients and varies between different geographies. These findings highlight that the elevator mechanism is not the only obstacle when reprocessing reusable endoscopes; therefore, guidelines should recommend more surveillance of the endoscope channels as well.

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.

Duodenoscope-Acquired Infections: Risk Factors to Consider

In the wake of highly publicized duodenoscope-associated outbreaks caused by multidrug-resistant organisms (MDRO), a herculean effort was made to understand the conditions that led to these transmission events. Although there is now a clearer picture on how these outbreaks happened, there are still significant data gaps when it comes to understanding the rate of duodenoscope-acquired infections (DAIs), especially in nonoutbreak situations. Recent publications indicate that DAIs are still occurring and suggest that infection rates are higher than currently believed. Given this data gap, it is important to identify those patient populations that are most at risk of postprocedure infection, so that appropriate infection control measures may be implemented. Although those patients receiving antibiotic prophylaxis are most at risk for infection, there are additional risk factors that should be considered. For the purposes of this review, risk factors for infection were divided into three broad categories as follows: (1) those that increase patient susceptibility to infection, (2) those related to the endoscopic procedure, and (3) those factors that put reusable duodenoscope inventories at risk of contamination. Infection risk is a complex interaction between the immune status of the patient, the characteristics of the infectious agent (antibiotic sensitivity, virulence factors, and epidemiology), and the environment of care. Because of this complexity, any assessment of the risk of infection should be performed on a case-by-case basis. There is a dearth of information on infection risk for those patients undergoing endoscopic retrograde cholangiopancreatograpy (ERCP), especially in the context of the development and implementation of new device technology, and new endoscopic procedures that are increasing in complexity. This narrative review was developed using the Medical Subject Heading (MeSH) terms to perform an electronic search in PubMed with the goal of generating a summary of the patient, procedural, and duodenoscope-associated factors that increase the risk of infection in patients undergoing ERCP. This review provides practical information regarding the segmentation of ERCP patients by infection risk, so that endoscopists can make informed decisions about the risk benefits of using enhanced duodenoscope technologies in the care of their patients.

Comparison of the disinfecting effect of sodium hypochlorite aqueous solution and surfactant on hospital kitchen hygiene using adenosine triphosphate swab testing

The Japanese Ministry of Health requires large-scale cooking facilities to use sodium hypochlorite aqueous solution (HYP) on food preparation tools, equipment, and facilities to prevent secondary contamination. This study aimed to compare the disinfecting effect of HYP and surfactant using adenosine triphosphate (ATP) swab testing on large-scale equipment and facilities that could not be disassembled and disinfected in hospital kitchen. From May 2018 to July 2018, ATP swab tests were performed on the following six locations in the Shizuoka Cancer Centre Dietary Department Kitchen: cooking counter, mobile cooking counter, refrigerator handle, conveyor belt, tap handle, and sink. Six relative light unit (RLU) measurements were taken from each location. The log₁₀ values of the RLU measurements were evaluated by dividing the samples into two groups: the control group (surfactant followed by HYP swabbing) and the HYP group (HYP swabbing only). The results showed that the RLUs (log₁₀ values) in both the groups improved after disinfection (p<0.05), except for the RLUs (log₁₀ values) of the mobile cooking counter, tap handle, and sink in the control group after the HYP swab. The changes in the RLU (log₁₀ value) did not differ between the two groups for all locations of the kitchen. Hence, HYP swabbing of large-scale equipment and facilities provides the same level of disinfection as surfactants and can be as beneficial.

A newly designed duodenoscope with detachable distal cap significantly reduces organic residue contamination after reprocessing

BACKGROUND

A newly designed duodenoscope with detachable distal cap may reduce bacterial contamination by allowing better access to the elevator. We compared bacterial contamination and organic residue evaluated by rapid adenosine triphosphate (ATP) test and culture from duodenoscopes with detachable vs. fixed distal caps after high-level disinfection (HLD).

METHODS

During December 2018-April 2019, 108 used newly designed duodenoscopes were enrolled. In group A (n = 54), the distal cap of the duodenoscope was detached before manual cleaning. In group B (n = 54), the distal cap was not detached. After HLD, samples were collected from the elevator, submitted for culture, and evaluated using the ATP test, using the cutoff value of 40 relative light units (RLUs).

RESULTS

After HLD, the proportion of potential bacterial contamination and organic residue in group A was significantly lower than in group B (37.0 % vs. 75.9 %; P  < 0.001; relative risk 0.49, 95 % confidence interval 0.33-0.71), and also confirmed by median ATP values (45.2 vs. 141.0 RLU; P  < 0.001). In group B, one sample culture was positive for nonpathogenic bacteria. Pathogenic bacteria were not found in any culture from either group.

CONCLUSIONS

The detachable distal cap was more effective at eliminating bacterial contamination and reducing organic residue than a fixed cap. Nonpathogenic bacteria were detected in the fixed cap group after reprocessing. The ATP test with 40 RLU cutoff is a practical method to ensure the cleanliness of duodenoscope reprocessing without the need to wait for bacterial culture results.

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.

Rate and impact of duodenoscope contamination: A systematic review and meta-analysis

BACKGROUND

Multiple infection outbreaks have been linked to contaminated duodenoscopes worldwide. However, the contamination rate of patient-ready duodenoscopes varies highly amongst published studies testing this subject. We aimed to estimate the contamination rate of reprocessed patient-ready duodenoscopes for endoscopic retrograde cholangio-pancreatography (ERCP) based on currently available data.

METHODS

We searched the PubMed and Embase databases from January 1, 2010 until March 10, 2020, for citations investigating contamination rates of reprocessed patient-ready duodenoscopes. Studies not assessing other types of endoscopes than duodenoscopes were excluded from the analysis. Study eligibility and data extraction was evaluated by three reviewers independently. A random-effects model (REM) based on the proportion distribution was used to calculate the pooled total contamination rate of reprocessed patient-ready duodenoscopes. Subgroup analyses were carried out to assess contamination rates when using different reprocessing methods by comparing single high-level disinfection (HLD) with double HLD and ethylene oxide (EtO) gas sterilization. Additionally, we investigated the contamination rate between studies conducted following an outbreak compared to non-outbreak-initiated studies.

FINDINGS

We identified 15 studies that fulfilled the inclusion, which included 925 contaminated duodenoscopes from 13,112 samples. The calculated total weighted contamination rate was 15.25% ± 0.018 (95% confidence interval [Cl]: 11.74% - 18.75%). The contamination rate after only using HLD was 16.14% ± 0.019 (95% Cl: 12.43% - 19.85%) and after using either dHLD or EtO the contamination rate decreased to 9.20% ± 0.025 (95% Cl: 4.30% - 14.10%). Studies conducted following an outbreak (n=4) showed a 5.72% ± 0.034 (95% Cl: 0.00% - 12.43%) contamination rate, and non-outbreak-initiated studies (n=11) revealed a contamination rate of 21.50% ± 0.031 (95% Cl: 15.35% - 27.64%).

INTERPRETATION

This is the first meta-analysis to estimate the contamination rate of patient-ready duodenoscopes used for ERCP. Based on the available literature, our analysis demonstrates that there is a 15.25% contamination rate of reprocessed patient-ready duodenoscopes. Additionally, the analysis indicates that dHLD and EtO reprocessing methods are superior to single HLD but still not efficient in regards to cleaning the duodenoscopes properly. Furthermore, studies conducted following an outbreak did not entail a higher contamination rate compared to non-outbreak-initiated studies.

FUNDING

The authors received no financial support for the research, authorship, and/or publication of this article.

Duodenoscope-associated infections: a review

Flexible digestive endoscopes are used for the management of various conditions with hundreds of thousands of therapeutic procedures performed worldwide each year. Duodenoscopes are indispensable tools for the delivery of minimally invasive vital care of numerous pancreaticobiliary disorders. Despite the fact that nosocomial infections after endoscopic retrograde cholangiopancreatography (ERCP) have always been among the most frequently cited postprocedural complications, recent emergence of duodenoscope-transmitted multiple drug-resistant bacterial infections has led to intense research and debate yet with no clearly delineated solution. Duodenoscope-transmitted nosocomial infections have become one of the most visible topics in the recent literature. Hundreds of high-impact articles have therefore been published in the last decade. This review article discusses how such infections were seen in the past and what is the current situation in both research and practice and thus tries to solve some of the unanswered questions for the future. With the persistence of nosocomial infections despite strict adherence to both manufacturer-issued reprocessing protocols and international guidelines and regulations, an urgent and proper microbiologically driven common action is needed for controlling such nosocomial worldwide threat.

What's new in reprocessing endoscopes: Are we going to ensure "the needs of the patient come first" by shifting from disinfection to sterilization?

Millions of gastrointestinal endoscopes are performed each year in the United States. Gastrointestinal endoscopes become highly contaminated during use (ie, internal channels contain 7-10-log₁₀ enteric microorganisms). Currently, endoscopes (eg, bronchoscopes and gastrointestinal endoscopes) are classified as semicritical items because they contact intact mucous membranes and most commonly undergo cleaning followed by high-level disinfection, which may result in as little as a 6-log₁₀ reduction of microorganisms. Therefore, and not surprisingly, in recent years there have been multiple reports that have documented that endoscopes, especially duodenoscopes, frequently remain contaminated with bacterial pathogens after proper cleaning and disinfection. Multiple outbreaks of multidrug-resistant organisms from contaminated duodenoscopes have resulted in substantial death and morbidity. Because duodenoscopes commonly contact nonintact mucous membranes and sterile tissue, such endoscopes should be considered critical items. We propose that to ensure patient safety, we follow the Spaulding scheme and move from high-level disinfection to sterilization of reusable endoscopes or use an alternative diagnostic/therapeutic method (eg, disposable sterile endoscopes).

Australian infection control in endoscopy consensus statements on carbapenemase-producing Enterobacteriaceae

Outbreaks of carbapenemase-producing Enterobacteriaceae clinical infections related to endoscopic transmission are well documented. The high morbidity and mortality associated with these infections emphasizes the need to reassess endoscopic reprocessing protocols. The Gastroenterological Society of Australia established a multi-society committee to formulate evidence-based consensus statements on the prevention and management of endoscopic transmission of carbapenemase-producing Enterobacteriaceae. A literature search was undertaken utilizing the MEDLINE database. Further references were sourced from published paper bibliographies. Nine statements were formulated. Using the Delphi methodology, the statements were initially reviewed electronically by the committee members and subsequently at a face-to-face meeting in Melbourne, Australia. After further discussion, four additional sub-statements were added resulting in a total of 13 statements. Each statement was assessed for level of evidence, recommendation grade and the voting on recommendation was recorded. For a statement to be accepted, five out of six committee members had to "accept completely" or "accept with some reservation." All 13 statements achieved consensus agreement. Eleven statements achieved 100% "accepted completely." Two statements were 83% "accepted completely" and 17% "accepted with some reservation." Of particular significance, automated flexible endoscope reprocessors were mandated for high-level disinfection, and the use of forced-air drying cabinets was mandated for endoscope storage. These evidence-based statements encourage preventative strategies with the aim of ensuring the highest possible standards in flexible endoscope reprocessing thereby optimizing patient safety. They must be considered in addition to the broader published guidelines on infection control in endoscopy.

Safely reprocessing duodenoscopes: current evidence and future directions

Highly publicised outbreaks of various infections related to the use of duodenoscopes have increased public awareness of the once arcane and largely ignored subject of endoscope reprocessing. Since 2015, national professional societies, multiple federal agencies, and even the US Senate have written reports and guidelines on duodenoscope reprocessing. However, their recommendations are sometimes contradictory and difficult to implement, and new research on the topic is published regularly which further complicates the situation. With this flood of new and sometimes contradictory information, clinicians can feel confused about how to assure the safety of their patients undergoing duodenosocopy. This Review summarises the most salient current research on duodenoscope-associated outbreaks and reprocessing, and aims to provide clinicians with practical information applicable to their practice.

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.

Use of adenosine triphosphate to audit reprocessing of flexible endoscopes with an elevator mechanism

BACKGROUND

There have been reported outbreaks of carbapenem-resistant Enterobacteriaceae infections linked to endoscopes with elevator mechanisms. Adenosine triphosphate (ATP) testing has been used as a marker for bioburden and monitoring manual cleaning for flexible endoscopes with and without an elevator mechanism. The objective of this study was to determine whether routine ATP testing could identify areas of improvement in cleaning of endoscopes with an elevator mechanism.

METHODS

ATP testing after manual cleaning of TJF-Q180V duodenoscopes and GF-UCT180 linear echoendoscopes (Olympus America Inc, Center Valley, PA) was implemented. Samples were tested from the distal end, the elevator mechanism, and water flushed through the lumen of the biopsy channel. Data were recorded and compared by time point, test point, and reprocessing technician.

RESULTS

Overall failure rate was 6.99% (295 out of 4,219). The highest percentage of failed ATP tests (17.05%) was reported in the first quarter of routine testing, with an overall decrease in rates over time. The elevator mechanism and working channel lumen had higher failure rates than the distal end. Quality of manual cleaning between reprocessing technicians showed variation.

CONCLUSION

ATP testing is effective in identifying residual organic material and improving quality of manual cleaning of endoscopes with an elevator mechanism. Cleaning efficacy is influenced by reprocessing technicians and location tested on the endoscope. Close attention to the working channel and elevator mechanism during manual cleaning is warranted.

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.

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.

Prospective study of the feasibility of point-of-care testing strategy for carbapenem-resistant organism detection

BACKGROUND/AIMS

 In an investigator-initiated, prospective study, we evaluated the feasibility of a five-gene sequence point-of-care (POC) testing strategy (Xpert CARBA-R Assay, Cepheid Inc., Sunnyvale, CA, USA), compared to reference laboratory PCR (48 - 72 hours turnaround time, two gene sequences), in patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) and in a hospital outbreak investigation.

METHODS

 After informed consent, patients undergoing ERCP (September 2015 - April 2016, n = 191) at Mayo Clinic and potential hospital contacts (n = 9) of an index carbapenem-resistant organism (CRO)-positive inpatient were included. Two rectal swabs, one each for reference and POC assays were obtained. The Xpert CARBA-R Assay enables qualitative rapid detection of five beta-lactamase gene sequences associated with carbapenem-non-susceptibility in Gram-negative bacteria. Feasibility parameters (specimen processing and assay run time, ease of use) and percent agreement between the tests were calculated using JMP Pro11 (SAS Corp, Cary, NC, USA).

RESULTS

 Mean age was 62 ± 15 years; 108 (54 %) were male. Both tests were successfully performed in all patients. The POC test was rated by endoscopy nurses as easy/very easy to conduct in 193 patients (97 %); median assay run time and median time for specimen collection and processing were 55 minutes (interquartile range IQR: 53 - 55 minutes) and 3 minutes (IQR: 3 - 6 minutes), respectively. In 200/201 (99.5 %) tests, there was agreement between the POC and reference PCR.

CONCLUSIONS

 The more comprehensive POC CRO testing of patients in the endoscopy suite is feasible and results are available in < 1 hour. This strategy may enable rapid risk stratification of duodenoscope exposure to CRO and potentially improve operational efficiency and decrease costs.