The use of rapid indicators for the detection of organic residues on clinically used gastrointestinal endoscopes with and without visually apparent debris

Perspectives on research needs in healthcare epidemiology and antimicrobial stewardship: what's on the horizon - Part I

In this overview, we articulate research needs and opportunities in the field of infection prevention that have been identified from insights gained during operative infection prevention work, our own research in healthcare epidemiology, and from reviewing the literature. The 10 areas of research need are: 1) transmissions and interruptions, 2) personal protective equipment and other safety issues in occupational health, 3) climate change and other crises, 4) device, diagnostic, and antimicrobial stewardship, 5) implementation and de-implementation, 6) health care outside the acute care hospital, 7) low- and middle-income countries, 8) networking with the "neighbors", 9) novel research methodologies, and 10) the future state of surveillance. An introduction and chapters 1-5 are presented in part I of the article, and chapters 6-10 and the discussion in part II. There are many barriers to advancing the field, such as finding and motivating the future IP workforce including professionals interested in conducting research, a constant confrontation with challenges and crises, the difficulty of performing studies in a complex environment, the relative lack of adequate incentives and funding streams, and how to disseminate and validate the often very local quality improvement projects. Addressing research gaps now (i.e., in the postpandemic phase) will make healthcare systems more resilient when facing future crises.

New Hydrogels Nanocomposites Based on Chitosan, 2-Formylphenylboronic Acid, and ZnO Nanoparticles as Promising Disinfectants for Duodenoscopes Reprocessing

New hydrogels nanocomposites, based on iminoboronate hydrogels and ZnO nanoparticles (ZnO-NPs), were obtained and characterised in order to develop a new class of disinfectants able to fight the nosocomial infections produced by duodenoscopes investigation procedures. The formation of the imine linkages between chitosan and the aldehyde was demonstrated using NMR and FTIR spectroscopy, while the supramolecular architecture of the developed systems was evaluated via wide-angle X-ray diffraction and polarised optical microscopy. The morphological characterisation of the systems via scanning electron microscopy revealed the highly porous structure of the materials, in which no ZnO agglomeration could be observed, indicating the very fine and homogenous encapsulation of the nanoparticles into the hydrogels. The newly synthetised hydrogels nanocomposites was proven to have synergistic antimicrobial properties, being very efficient as disinfectants against reference strains as: Enterococcus faecalis, Klebsiella pneumoniae, and Candida albicans.

Transmission of oral microbiota to the biliary tract during endoscopic retrograde cholangiography

BACKGROUND

Endoscopic retrograde cholangiography (ERC) possesses a translocation risk of microbes to the biliary system. We studied bile contamination during ERC and its impact on patients' outcome in a real-life-situation.

METHODS

Ninety-nine ERCs were analyzed and microbial samples were taken from the throat before and from bile during ERC and from irrigation fluid of the duodenoscope before and after ERC.

RESULTS

91.2% of cholangitis patients had detectable microbes in the bile (sensitivity 91%), but the same was true for 86.2% in the non-cholangitis group. Bacteroides fragilis (p=0.015) was significantly associated with cholangitis. In 41.7% of ERCs with contaminated endoscopes these microbes were found in the bile after the procedure. Analysis of duodenoscopes' irrigation liquid after ERC matched the microbial bile analysis of these patients in 78.8%. Identical microbial species were in throat and in bile samples of the same ERC in 33% of all cases and in 45% in the non-cholangitis group. Transmission of microbes to the biliary tract did not result in more frequent cholangitis, longer hospital stays, or worse outcome.

CONCLUSIONS

During ERC bile samples are regularly contaminated with microbes of the oral cavity but it did not affect clinical outcome.

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.

Sans Standardization: Effective Endoscope Reprocessing

Bronchoscopy is a commonly performed procedure within thoracic and critical care medicine. Modern bronchoscopes are technologically advanced tools made of fragile electronic components. Their design is catered to allow maximum maneuverability within the semi-rigid tracheobronchial tree. Effective cleaning and reprocessing of these tools can be a challenge. Although highly functional, the design poses several challenges when it comes to reprocessing. It is a very important step, and lapses in the procedure have been tied to nosocomial infections. The process lacks universal standardization; several organizations have developed their own recommendations. Data have shown that key stakeholders are not fully versed in the essentials of endoscope reprocessing. A significant knowledge gap exists between those performing bronchoscopy and those who are stewards of effective endoscope reprocessing. To service as a resource for bronchoscopists, this study summarizes the steps of effective reprocessing, details the important elements within a health-care facility that houses this process, and reviews some of the current data regarding the use of disposable endoscopes.

Quality Systems Approach for Endoscope Reprocessing: You Don't Know What You Don't Know!

Several factors affect the efficacy of endoscope reprocessing, including human factors, inadequate cleaning, simethicone residuals, moisture in channels during storage, and biofilm or buildup biofilm formation. These factors all contribute to contamination of patient-ready endoscopes that may contribute to transmission of microorganisms resulting in infection and/or colonization. This article reviews monitoring as part of a quality management system that includes manual cleaning, dry storage, and culture to detect endoscope contamination. The published data for rapid tests that detect organic residuals and adenosine triphosphate to monitor manual cleaning are reviewed.

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.

Challenges in achieving effective high-level disinfection in endoscope reprocessing

Endoscope reprocessing is often ineffective, and microbes frequently remain on endoscopes after the use of high-level disinfectants (HLDs). Several factors impact reprocessing effectiveness, including non-adherence to guidelines, use of damaged endoscopes, use of insoluble products during endoscopy, insufficient cleaning, contaminated rinse water, and inadequate drying before storage. Our team suspected that issues with HLD chemistries and monitoring could also contribute to reprocessing failures. We conducted a mixed-methods analysis of published literature, our interviews with frontline personnel, and evidence from our previous studies. The evidence showed that reusable HLDs commonly failed tests for minimum effective concentration (MEC) before their maximum usage periods. MEC tests also detected failures associated with single-use HLDs that did not fully deploy. These failures were due to product issues, process complexities, and personnel non-adherence with guidelines and manufacturer instructions. HLDs will likely continue to be used for the foreseeable future. More research is needed to assess real-world practice patterns related to the high-level disinfection step and MEC testing and to establish more realistic usage periods for reusable HLD chemistries. Manufacturers and researchers should evaluate the ability of technological solutions and engineered safeguards to overcome human error. Recognition of the need for quality improvement is growing, and infection preventionists should take action to build on this momentum and collaborate with manufacturers, endoscopists, and reprocessing personnel to improve the effectiveness of high-level disinfection.

Duodenoscope-Related Outbreak of a Carbapenem-Resistant Klebsiella pneumoniae Identified Using Advanced Molecular Diagnostics

Background

Carbapenem-resistant Klebsiella pneumoniae infections are increasingly prevalent in North American hospitals. We describe an outbreak of carbapenem-resistant K. pneumoniae containing the blaOXA-232 gene transmitted by contaminated duodenoscopes during endoscopic retrograde cholangiopancreatography (ERCP) procedures.

Methods

An outbreak investigation was performed when 9 patients with blaOXA-232 carbapenem-resistant K. pneumoniae infections were identified at a tertiary care hospital. The investigation included 2 case-control studies, review of duodenoscope reprocessing procedures, and culture of devices. Carbapenem-resistant Enterobacteriacieae (CRE) isolates were evaluated with polymerase chain reaction analysis for carbapenemase genes, and isolates with the blaOXA-232 gene were subjected to whole-genome sequencing and chromosome single-nucleotide polymorphism analysis. On recognition of ERCP as a key risk factor for infection, targeted patient notification and CRE screening cultures were performed.

Results

Molecular testing ultimately identified 17 patients with blaOxa-232 carbapenem-resistant K. pneumoniae isolates, including 9 with infections, 7 asymptomatic carriers who had undergone ERCP, and 1 additional patient who had been hospitalized in India and was probably the initial carrier. Two case-control studies established a point-source outbreak associated with 2 specific duodenoscopes. A field investigation of the use, reprocessing, and storage of deuodenoscopes did not identify deviations from US Food and Drug Administration or manufacturer recommendations for reprocessing.

Conclusions

This outbreak demonstrated the previously underappreciated potential for duodenoscopes to transmit disease, even after undergoing high-level disinfection according to manufacturers' guidelines.

Evaluation of the total adenylate (ATP + ADP + AMP) test for cleaning verification in healthcare settings

Introduction

Evaluation of cleaning methods is the first step in the prevention of healthcare-associated infections. ATP hygiene monitoring tests are widely used for assessing the effectiveness of cleaning procedures. The test is easy to use and gives immediate results, however, ATP can be metabolized and degraded to ADP and AMP. Recently, a total adenylate [ATP + ADP + AMP(A3)] monitoring test has been developed. Our objective was to evaluate the usefulness of the A3 test for cleaning verification in healthcare settings.

Methods

The detection sensitivities of the ATP and the A3 tests were compared using blood, and debris derived from gloved-hand method and endoscopes immediately after endoscopic examination. The performance of the A3 test in monitoring cleanliness of high touch surfaces in the hospital and endoscopes at each cleaning step was also evaluated.

Results

For the hemolysate, the measurement values of the A3 test were stable, although ATP was promptly degraded. In debris from hands, the amount of A3 was 20 times higher than that of ATP. The detection sensitivities of the A3 test on residues derived from gastroscopes and colonoscopes were 3 and 8 times higher, respectively, than those from the ATP test. A field study indicated that a large number of microorganisms tend to show high A3 values on high touch surfaces in the hospital and on endoscopes.

Conclusions

The A3 test showed higher detection sensitivities than the conventional ATP test for organic debris associated with healthcare settings.

Widespread clinical use of simethicone, insoluble lubricants, and tissue glue during endoscopy: A call to action for infection preventionists

BACKGROUND

Current methods for reprocessing flexible endoscopes do not consistently eliminate organic soil. The off-label use of simethicone as a defoaming agent may contribute to reprocessing failures, and endoscope manufacturers have cautioned against its use.

METHODS

We sought evidence of simethicone use by interviewing hospital personnel, conducting audits, inspecting endoscopes, and conducting tests.

RESULTS

Researchers examined 69 fully reprocessed endoscopes in 4 hospitals. Microbial cultures were positive for ≥50% of endoscopes. Researchers observed cloudy, shimmery fluid resembling simethicone inside channels and under a duodenoscope elevator mechanism. Crystallized white fragments were observed protruding from a gastroscope water jet outlet. Oily, sticky residue was found on endoscopes, and a 3-dimensional mass was found inside an endoscopic ultrasound endoscope. Hospital personnel reported the use of simethicone, cooking oil and silicone sprays, and tissue glue during endoscopy.

DISCUSSION

The off-label use of defoaming agents, lubricants, and tissue glue is common and many endoscopists consider these products essential. Our findings suggest these substances are not removed during reprocessing and may impact reprocessing effectiveness.

CONCLUSIONS

Infection preventionists should determine whether these products are used in their institutions and evaluate methods for removing them. New policies may be needed to support procedural success and effective endoscope reprocessing.

A Systematic Review of Disposable Sheath Use During Flexible Endoscopy

Flexible endoscopes are exposed to blood, mucus, and other secretions during procedures. Single-use sheaths are designed to prevent contact between contaminants and reusable endoscope components. This systematic review examined findings from 22 studies that assessed endoscopic sheath use during urologic, gastrointestinal, or respiratory procedures. The evidence showed that sheaths were durable and yielded faster endoscope turnover times because their reusable components did not require high-level disinfection or sterilization. After a brief learning period, health care providers successfully assembled and maneuvered sheathed endoscopes. Patients generally did not experience greater discomfort during procedures in which sheaths were used. Microbial cultures of sheathed endoscopes were negative or similar to unsheathed endoscopes. More research is needed to evaluate the potential effect of disposable sheaths on infection risks. The evidence suggests that sheaths are a viable option for reliably providing a barrier between endoscopes and patients without affecting the quality of endoscopic procedures.

Evaluation of adenosine triphosphate test for cleaning assessment of gastroscopes and the effect on workload in a busy endoscopy center

OBJECTIVE

Using adenosine triphosphate (ATP) tests to assess manual cleaning of gastroscopes and to determine the associated workload in a busy endoscopy unit.

METHODS

Patient-used gastroscopes were sampled before and after cleaning to assess ATP levels, bioburden, and protein. Samples were collected by flushing 20 mL of sterile water through the biopsy port to the distal end. Time spent for reprocessing and performing the ATP test was recorded.

RESULTS

Twenty-four samples were collected from 10 gastroscopes. After manual cleaning, 14/24 (58.3%) samples had no microbial growth (mean, 21 colony-forming units/cm²), and in 22/24 (91.7%) samples the protein was undetectable (mean, 0.04 µg/cm²). ATP test was above the cutoff (200 relative light units [RLU]) in 17/24 (70.8%) samples (mean, 498 RLU). After the second cleaning, 11/17 (64.7%) gastroscopes still failed the ATP test (mean, 321.2 RLU). The mean time spent to perform manual cleaning and ATP tests was 16 and 8 minutes, respectively. Hence, each test increased the length of time for cleaning plus testing cleanliness by 50%.

CONCLUSION

Further studies regarding the optimal cutoff for ATP tests are needed. ATP tests for cleaning monitoring are easy to perform and provide immediate feedback to the team. However, the increased workload needs to be considered.

Residual moisture and waterborne pathogens inside flexible endoscopes: Evidence from a multisite study of endoscope drying effectiveness

BACKGROUND

Endoscopy-associated infection transmission is frequently linked to inadequate reprocessing. Residual organic material and moisture may foster biofilm development inside endoscopes. This study evaluated the effectiveness of endoscope drying and storage methods and assessed associations between retained moisture and contamination.

METHODS

Endoscope reprocessing, drying, and storage practices were assessed at 3 hospitals. Researchers performed visual examinations and tests to detect fluid and contamination on patient-ready endoscopes.

RESULTS

Fluid was detected in 22 of 45 (49%) endoscopes. Prevalence of moisture varied significantly by site (5%; 83%; 85%; P < .001). High adenosine triphosphate levels were found in 22% of endoscopes, and microbial growth was detected in 71% of endoscopes. Stenotrophomonas maltophilia, Citrobacter freundii, and Lecanicillium lecanii/Verticillium dahliae were found. Retained fluid was associated with significantly higher adenosine triphosphate levels (P < .01). Reprocessing and drying practices conformed with guidelines at 1 site and were substandard at 2 sites. Damaged endoscopes were in use at all sites.

CONCLUSIONS

Inadequate reprocessing and insufficient drying contributed to retained fluid and contamination found during this multisite study. More effective methods of endoscope reprocessing, drying, and maintenance are needed to prevent the retention of fluid, organic material, and bioburden that could cause patient illness or injury.

Effectiveness of Reprocessing for Flexible Bronchoscopes and Endobronchial Ultrasound Bronchoscopes

BACKGROUND

Infections have been linked to inadequately reprocessed flexible bronchoscopes, and recent investigations determined that pathogen transmission occurred even when bronchoscope cleaning and disinfection practices aligned with current guidelines. This multisite, prospective study evaluated the effectiveness of real-world bronchoscope reprocessing methods, using a systematic approach.

METHODS

This study involved direct observation of reprocessing methods for flexible bronchoscopes, multifaceted evaluations performed after manual cleaning and after high-level disinfection, and assessments of storage conditions. Visual inspections of ports and channels were performed using lighted magnification and borescopes. Contamination was detected using microbial cultures and tests for protein, hemoglobin, and adenosine triphosphate (ATP). Researchers assessed reprocessing practices, and storage cabinet cleanliness was evaluated by visual inspection and ATP tests.

RESULTS

Researchers examined 24 clinically used bronchoscopes. After manual cleaning, 100% of bronchoscopes had residual contamination. Microbial growth was found in 14 fully reprocessed bronchoscopes (58%), including mold, Stenotrophomonas maltophilia, and Escherichia coli/Shigella species. Visible irregularities were observed in 100% of bronchoscopes, including retained fluid; brown, red, or oily residue; scratches; damaged insertion tubes and distal ends; and filamentous debris in channels. Reprocessing practices were substandard at two of three sites.

CONCLUSIONS

Damaged and contaminated bronchoscopes were in use at all sites. Inadequate reprocessing practices may have contributed to bioburden found on bronchoscopes. However, even when guidelines were followed, high-level disinfection was not effective. A shift toward the use of sterilized bronchoscopes is recommended. In the meantime, quality management programs and updated reprocessing guidelines are needed.

The effectiveness of sterilization for flexible ureteroscopes: A real-world study

BACKGROUND

There are no guidelines or quality benchmarks specific to ureteroscope reprocessing, and patient injuries and infections have been linked to ureteroscopes. This prospective study evaluated ureteroscope reprocessing effectiveness.

METHODS

Reprocessing practices at 2 institutions were assessed. Microbial cultures, biochemical tests, and visual inspections were conducted on sterilized ureteroscopes.

RESULTS

Researchers examined 16 ureteroscopes after manual cleaning and sterilization using hydrogen peroxide gas. Every ureteroscope had visible irregularities, such as discoloration, residual fluid, foamy white residue, scratches, or debris in channels. Tests detected contamination on 100% of ureteroscopes (microbial growth 13%, adenosine triphosphate 44%, hemoglobin 63%, and protein 100%). Contamination levels exceeded benchmarks for clean gastrointestinal endoscopes for hemoglobin (6%), adenosine triphosphate (6%), and protein (100%). A new, unused ureteroscope had hemoglobin and high protein levels after initial reprocessing, although no contamination was found before reprocessing.

CONCLUSIONS

Flexible ureteroscope reprocessing methods were insufficient and may have introduced contamination. The clinical implications of residual contamination and viable microbes found on sterilized ureteroscopes are unknown. Additional research is needed to evaluate the prevalence of suboptimal ureteroscope reprocessing, identify sources of contamination, and determine clinical implications of urinary tract exposure to reprocessing chemicals, organic residue, and bioburden. These findings reinforce the need for frequent audits of reprocessing practices and the routine use of cleaning verification tests and visual inspection as recommended in reprocessing guidelines.

Guideline Implementation: Processing Flexible Endoscopes

The updated AORN "Guideline for processing flexible endoscopes" provides guidance to perioperative, endoscopy, and sterile processing personnel for processing all types of reusable flexible endoscopes and accessories in all procedural settings. This article focuses on key points of the guideline to help perioperative personnel safely and effectively process flexible endoscopes to prevent infection transmission. The key points address verification of manual cleaning, mechanical cleaning and processing, storage in a drying cabinet, determination of maximum storage time before reprocessing is needed, and considerations for implementing a microbiologic surveillance program. Perioperative RNs should review the complete guideline for additional information and for guidance when writing and updating policies and procedures.

Monitoring of endoscope reprocessing with an adenosine triphosphate (ATP) bioluminescence method

Background: The arising challenges over endoscope reprocessing quality proposes to look for possibilities to measure and control the process of endoscope reprocessing. Aim: The goal of this study was to evaluate the feasibility of monitoring endoscope reprocessing with an adenosine triphosphate (ATP) based bioluminescence system. Methods: 60 samples of eight gastroscopes have been assessed from routine clinical use in a major university hospital in Germany. Endoscopes have been assessed with an ATP system and microbial cultures at different timepoints during the reprocessing. Findings: After the bedside flush the mean ATP level in relative light units (RLU) was 19,437 RLU, after the manual cleaning 667 RLU and after the automated endoscope reprocessor (AER) 227 RLU. After the manual cleaning the mean total viable count (TVC) per endoscope was 15.3 CFU/10 ml, and after the AER 5.7 CFU/10 ml. Our results show that there are reprocessing cycles which are not able to clean a patient used endoscope. Conclusion: Our data suggest that monitoring of flexible endoscope with ATP can identify a number of different influence factors, like the endoscope condition and the endoscopic procedure, or especially the quality of the bedside flush and manual cleaning before the AER. More process control is one option to identify and improve influence factors to finally increase the overall reprocessing quality, best of all by different methods. ATP measurement seems to be a valid technique that allows an immediate repeat of the manual cleaning if the ATP results after manual cleaning exceed the established cutoff of 200 RLU.

Residual contamination and bioburden after reprocessing of single-use endoscopic ultrasound needles: An ex vivo study

BACKGROUND AND AIM

Endoscopic ultrasound (EUS) aspiration needles are single-use devices. However, in many centers, because of cost-constraints, these devices are reused multiple times. We studied microbiological contamination and bioburden on reprocessed needles to evaluate whether these devices can be successfully sterilized.

METHODS

We studied 10 EUS needles each of 19 G, 22 G, and 25 G in size, and five 22-G ProCore needles. After initial use, each needle was reprocessed by a standardized protocol. We used standard microbiological cultures, as well as ATP bioluminescence technique to quantify bioburden as relative light units (RLU). We defined significant soil contamination by RLU values >200. We also used extractant fluid to disrupt cell membranes in an attempt to enhance ATP detection.

RESULTS

We found culture positivity in 3/34 (8.8%), and detectable bioburden on the exposed surface of 33/35 (94.3%), and inside lumen of 29 (82.9%) reprocessed FNA needles. Significant bioburden was found in three (8.6%) and two (5.7%) needles on the surface and lumen, respectively. We found that use of extractant fluid enhanced detection of bioburden. Larger (19 G) needles had higher surface contamination (P = 0.016), but there was no relation of luminal contamination with needle diameter (P = 0.138). Sheath design and presence of side bevel did not influence extent of contamination. There was significant correlation between the surface and intraluminal bioburden (P < 0.001).

CONCLUSIONS

There is significant bioburden in reprocessed EUS needles; standard microbiological cultures have low sensitivity for detection of needle contamination. We have provided objective evidence for the futility of reprocessing attempts, and practice of EUS needle reuse should be discontinued.

Longitudinal assessment of reprocessing effectiveness for colonoscopes and gastroscopes: Results of visual inspections, biochemical markers, and microbial cultures

BACKGROUND

Flexible endoscopes are currently reused following cleaning and high-level disinfection. Contamination has been found on endoscopes, and infections have been linked to gastrointestinal, respiratory, and urologic endoscopes.

METHODS

This longitudinal study involved visual inspections with a borescope, microbial cultures, and biochemical tests for protein and adenosine triphosphate to identify endoscopes in need of further cleaning or maintenance. Three assessments were conducted over a 7-month period. Control group endoscopes reprocessed using customary practices were compared with intervention group endoscopes subjected to more rigorous reprocessing.

RESULTS

At final assessment, all endoscopes (N = 20) had visible irregularities. Researchers observed fluid (95%), discoloration, and debris in channels. Of 12 (60%) endoscopes with microbial growth, 4 had no growth until after 48 hours. There were no significant differences in culture results by study group, assessment period, or endoscope type. Similar proportions of control and intervention endoscopes (~20%) exceeded postcleaning biochemical test benchmarks. Adenosine triphosphate levels were higher for gastroscopes than colonoscopes (P = .014). Eighty-five percent of endoscopes required repair due to findings.

CONCLUSIONS

More rigorous reprocessing was not consistently effective. Seven-day incubation allowed identification of slow-growing microbes. These findings bolster the need for routine visual inspection and cleaning verification tests recommended in new reprocessing guidelines.

Assessing residual contamination and damage inside flexible endoscopes over time

Researchers evaluated flexible endoscope damage and contamination levels at baseline and 2 months later. Postcleaning test results exceeded benchmarks for all gastroscopes and no colonoscopes. Microbial growth was found in samples from 47% of fully reprocessed endoscopes at baseline and 60% at follow-up. Borescope examinations identified scratches, discoloration, debris, and fluid inside endoscopes. Irregularities changed over time. Study evaluations allowed damaged and contaminated endoscopes to be identified and re-reprocessed or sent for repairs.

Practical toolkit for monitoring endoscope reprocessing effectiveness: Identification of viable bacteria on gastroscopes, colonoscopes, and bronchoscopes

BACKGROUND

Experts have recommended microbiologic surveillance by external reference laboratories for certain flexible endoscopes. There is currently insufficient evidence on the feasibility and utility of cultures. Researchers evaluated a preassembled toolkit for collecting and processing samples from endoscopes.

METHODS

A pilot study was performed in a large academic medical center. A toolkit was used to aseptically sample biopsy ports and suction/biopsy channels of 5 gastroscopes, 5 colonoscopes, and 5 bronchoscopes after full reprocessing. Blinded specimens were packaged and transported on icepacks to a reference laboratory that used standard methodologies for microbial cultures.

RESULTS

The laboratory detected bacteria in samples from 60% of patient-ready endoscopes, including gram-positive and gram-negative species. Viable microbes (<10 CFU) were recovered from 2 gastroscopes, 3 colonoscopes, and 4 bronchoscopes. Stenotrophomonas maltophilia and Delftia acidovorans were recovered from all 3 endoscope types. Subsequent environmental testing detected S maltophilia in the reprocessing rinse water.

CONCLUSIONS

A preassembled toolkit facilitated the aseptic collection of samples for culturing by a reference laboratory that detected viable microbes on fully reprocessed endoscopes. Speciation allowed identification of potential pathogens and a possible common contamination source, demonstrating that microbial cultures may have value even when colony counts are low.

Simulated-use validation of a sponge ATP method for determining the adequacy of manual cleaning of endoscope channels

Background

The objective of this study was to validate the relative light unit (RLU) cut-off of adequate cleaning of flexible colonoscopes for an ATP (adenosine tri-phosphate) test kit that used a sponge channel collection method.

Methods

This was a simulated-use study. The instrument channel segment of a flexible colonoscope was soiled with ATS (artificial test soil) containing approximately 8 Log₁₀Enterococcus faecalis and Pseudomonas aeruginosa/mL. Full cleaning, partial cleaning and no cleaning were evaluated for ATP, protein and bacterial residuals. Channel samples were collected using a sponge device to assess residual RLUs. Parallel colonoscopes inoculated and cleaned in the same manner were sampled using the flush method to quantitatively assess protein and bacterial residuals. The protein and viable count benchmarks for adequate cleaning were <6.4 ug/cm² and <4 Log₁₀ cfu/cm².

Results

The negative controls for the instrument channel, over the course of the study remained low with on average 14 RLUs, 0.04 ug/cm² protein and 0.025 Log₁₀ cfu/cm². Partial cleaning resulted in an average of 6601 RLUs, 3.99 ug/cm², 5.25 Log₁₀ cfu/cm²E. faecalis and 4.48 Log₁₀ cfu/cm²P. aeruginosa. After full cleaning, the average RLU was 29 (range 7–71 RLUs) and the average protein, E. faecalis and P. aeruginosa residuals were 0.23 ug/cm², 0.79 and 1.61 Log₁₀ cfu/cm², respectively.

Conclusions

The validated cut-off for acceptable manual cleaning was set at ≤100 RLUs for the sponge collected channel ATP test kit.

Usefulness of Adenosinetriphosphate Bioluminescence Assay (ATPmetry) for Monitoring the Reprocessing of Endoscopes

OBJECTIVE

To assess the diagnostic value of an adenosinetriphosphate bioluminescence assay (ATPmetry) to monitor the effectiveness of the reprocessing of endoscopes compared with microbiologic sampling.

DESIGN

Diagnostic study.

SETTING

A 2,200-bed teaching hospital performing 5,000 to 6,000 endoscopic procedures annually.

INCLUSION CRITERIA

All samples from bronchial or gastrointestinal endoscopes whatever the context.

METHODS

Samples for microbiologic analysis and ATPmetry measurements were taken when each endoscope was inspected following reprocessing. Sampling was performed by flushing each endoscope with 300 mL Neutralizing Pharmacopeia Diluent thiosulfate rinsing solution divided equally between the endoscope channels. For each endoscope a series of 3 ATPmetry measurements were made on a vial containing the first jet from each channel and a second series on the whole sample.

RESULTS

Of 165 samples from endoscopes, 11 exceeded the acceptability threshold of 25 colony-forming units/endoscope. In the first jet collected, the median (interquartile range) level of ATPmetry was 30.5 (15.3–37.7) relative light units (RLU) for samples with 25 or fewer colony-forming units compared with 37.0 (34.7–39.3) RLU for samples with more than 25 colony-forming units (P=.008). For the whole sample, the median (interquartile range) level of ATPmetry was 24.8 (14.3–36.3) RLU and 36.3 (36.0–38.3) RLU (P=.006), respectively. After adjusting on the batch of cleansing solution used, no difference in ATPmetry values was found between microbiologically acceptable and unacceptable samples.

CONCLUSION

ATPmetry cannot be used as an alternative or complementary approach to microbiologic tests for monitoring the reprocessing of endoscopes in France

Infect. Control Hosp. Epidemiol. 2015;36(12):1437–1443

Persistent contamination on colonoscopes and gastroscopes detected by biologic cultures and rapid indicators despite reprocessing performed in accordance with guidelines

BACKGROUND

Pathogens have been transmitted via flexible endoscopes that were reportedly reprocessed in accordance with guidelines.

METHODS

Researchers observed reprocessing activities to ensure guideline compliance in a large gastrointestinal endoscopy unit. Contamination was assessed immediately after bedside cleaning, manual cleaning, high-level disinfection, and overnight storage via visual inspection, aerobic cultures, and tests for adenosine triphosphate (ATP), protein, carbohydrate, and hemoglobin.

RESULTS

All colonoscopes and gastroscopes were reprocessed in accordance with guidelines during the study. Researchers collected and tested samples during 60 encounters with 15 endoscopes. Viable microbes were recovered from bedside-cleaned (92%), manually cleaned (46%), high-level disinfected (64%), and stored (9%) endoscopes. Rapid indicator tests detected contamination (protein, carbohydrate, hemoglobin, or ATP) above benchmarks on bedside-cleaned (100%), manually cleaned (92%), high-level disinfected (73%), and stored (82%) endoscopes. Visible residue was never observed on endoscopes, but it was often seen on materials used to sample endoscopes. Seven endoscopes underwent additional reprocessing in response to positive rapid indicators. Control endoscope channels were free of biologic residue and viable microbes.

CONCLUSION

Despite reprocessing in accordance with US guidelines, viable microbes and biologic debris persisted on clinically used gastrointestinal endoscopes, suggesting current reprocessing guidelines are not sufficient to ensure successful decontamination.