Outbreaks of carbapenem-resistant Enterobacteriaceae infections associated with duodenoscopes: What can we do to prevent infections?

Carbapenem-resistant Enterobacterales sepsis following endoscopic retrograde cholangiopancreatography: risk factors for 30-day all-cause mortality and the development of a nomogram based on a retrospective cohort

BACKGROUND

Endoscopic retrograde cholangiopancreatography (ERCP) has become a routine endoscopic procedure that is essential for diagnosing and managing various conditions, including gallstone extraction and the treatment of bile duct and pancreatic tumors. Despite its efficacy, post-ERCP infections - particularly those caused by carbapenem-resistant Enterobacterales (CRE) - present significant risks. These risks highlight the need for accurate predictive models to enhance postprocedural care, reduce the mortality risk associated with post-ERCP CRE sepsis, and improve patient outcomes in the context of increasing antibiotic resistance.

OBJECTIVE

This study aimed to examine the risk factors for 30-day mortality in patients with CRE sepsis following ERCP and to develop a nomogram for accurately predicting 30-day mortality risk.

METHODS

Data from 195 patients who experienced post-ERCP CRE sepsis between January 2010 and December 2022 were analyzed. Variable selection was optimized via the least absolute shrinkage and selection operator (LASSO) regression model. Multivariate logistic regression analysis was then employed to develop a predictive model, which was evaluated in terms of discrimination, calibration, and clinical utility. Internal validation was achieved through bootstrapping.

RESULTS

The nomogram included the following predictors: age > 80 years (hazard ratio [HR] 2.61), intensive care unit (ICU) admission within 90 days prior to ERCP (HR 2.64), hypoproteinemia (HR 4.55), quick Pitt bacteremia score ≥ 2 (HR 2.61), post-ERCP pancreatitis (HR 2.52), inappropriate empirical therapy (HR 3.48), delayed definitive therapy (HR 2.64), and short treatment duration (< 10 days) (HR 5.03). The model demonstrated strong discrimination and calibration.

CONCLUSIONS

This study identified significant risk factors associated with 30-day mortality in patients with post-ERCP CRE sepsis and developed a nomogram to accurately predict this risk. This tool enables healthcare practitioners to provide personalized risk assessments and promptly administer appropriate therapies against CRE, thereby reducing mortality rates.

Biofilms on medical instruments and surfaces: Do they interfere with instrument reprocessing and surface disinfection

BACKGROUND

Biofilms are surface-attached communities of bacteria embedded in an extracellular matrix. This matrix shields the resident cells from desiccation, chemical perturbation, invasion by other bacteria, and confers reduced susceptibility to antibiotics and disinfectants. There is growing evidence that biofilms on medical instruments (especially endoscopes) and environmental surfaces interfere with cleaning and disinfection.

METHODS

The English literature on the impact of biofilms in medicine was reviewed with a focus on the impact of biofilms on reusable semicritical medical instruments and hospital environmental surfaces.

RESULTS

Biofilms are frequently present on hospital environmental surfaces and reusable medical equipment. Important health care...associated pathogens that readily form biofilms on environmental surfaces include Staphylococcus aureus, Pseudomonas aeruginosa, and Candida auris. Evidence has demonstrated that biofilms interfere with cleaning and disinfection.

DISCUSSION

New technologies such as ..úself-disinfecting..Ñ surfaces or continuous room disinfection systems may reduce or disrupt biofilm formation and are under study to reduce the impact of the contaminated surface environment on health care...associated infections.

CONCLUSIONS

Future research is urgently needed to develop methods to reduce or eliminate biofilms from forming on implantable medical devices, reusable medical equipment, and hospital surfaces.

Disinfection and sterilization: New technologies

BACKGROUND

Adherence to professional guidelines and/or manufacturer's instructions for use regarding proper disinfection and sterilization of medical devices is crucial to preventing cross transmission of pathogens between patients. Emerging pathogens (e.g., Candida auris) and complex medical devices provide new challenges.

METHODS

A search for published English articles on new disinfection and sterilization technologies was conducted by Google, Google scholar and PubMed.

RESULTS

Several new disinfection methods or products (e.g., electrostatic spraying, new sporicides, colorized disinfectants, "no touch" room decontamination, continuous room decontamination) and sterilization technologies (e.g., new sterilization technology for endoscopes) were identified.

CONCLUSIONS

These technologies should reduce patient risk.

Disinfection, sterilization and antisepsis: An overview

BACKGROUND

Each year in the United States there are approximately 100,000,000 outpatient/inpatient surgical procedures. Each of these procedures involves contact by a medical device or surgical instrument with a patient's sterile tissue and/or mucous membrane. A major risk of all such procedures is the introduction of infection.

METHODS

We searched published literature for articles on the use and effectiveness of disinfectants, sterilization methods and antiseptics.

RESULTS

The level of disinfection is dependent on the intended use of the object: critical (items that contact sterile tissue such as surgical instruments), semicritical (items that contact mucous membrane such as endoscopes), and noncritical (devices that contact only intact skin such as stethoscopes) items require sterilization, high-level disinfection and low-level disinfection, respectively. Cleaning must always precede high-level disinfection and sterilization. Antiseptics are essential to infection prevention as part of a hand hygiene program as well as other uses such as surgical hand antisepsis and pre-operative patient skin preparation.

CONCLUSIONS

When properly used, disinfection and sterilization can ensure the safe use of invasive and non-invasive medical devices. Cleaning should always precede high-level disinfection and sterilization. Strict adherence to current disinfection and sterilization guidelines is essential to prevent patient infections and exposures to infectious agents.

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.

Pathogenic Drug Resistant Fungi: A Review of Mitigation Strategies

Fungal pathogens cause significant human morbidity and mortality globally, where there is a propensity to infect vulnerable people such as the immunocompromised ones. There is increasing evidence of resistance to antifungal drugs, which has significant implications for cutaneous, invasive and bloodstream infections. The World Health Organization (WHO) published a priority list of fungal pathogens in October 2022, thus, highlighting that a crisis point has been reached where there is a pressing need to address the solutions. This review provides a timely insight into the challenges and implications on the topic of antifungal drug resistance along with discussing the effectiveness of established disease mitigation modalities and approaches. There is also a need to elucidate the cellular and molecular mechanisms of fungal resistance to inform effective solutions. The established fungal decontamination approaches are effective for medical device processing and sterilization, but the presence of pathogenic fungi in recalcitrant biofilms can lead to challenges, particularly during cleaning. Future design ideas for implantable and reusable medical devices should consider antifungal materials and appropriates for disinfection, and where it is relevant, sterilization. Preventing the growth of mycotoxin-producing fungi on foods through the use of appropriate end-to-end processes is advisable, as mycotoxins are recalcitrant and challenging to eliminate once they have formed.

Healthcare-Associated Infections (HAIs): Challenges and Measures Taken by the Radiology Department to Control Infection Transmission

Infections contracted during healthcare delivery in a hospital or ambulatory setting are collectively referred to as healthcare-associated infections (HAIs). Healthcare workers and patients alike are vulnerable to serious problems as a result of the risk of HAIs. In the healthcare system, HAIs are considered among the most common and serious health problems. However, the occurrence of HAIs differs between different types of clinical departments within the hospital. Recently, the risk of HAIs has been increasing in radiology departments globally due to the central role of radiology in guiding clinical decisions for the diagnosis, treatment, and monitoring of different diseases from almost all medical specialties. The radiology department is particularly vulnerable to HAIs because it serves as a transit hub for infected patients, non-infected patients, and healthcare workers. Furthermore, as the number of patients referred to radiology and the length of patient contact time has increased, thanks to modern imaging techniques such as computed tomography and magnetic resonance imaging, the risk of HAIs has also increased significantly. With the increasing use of interventional radiological procedures, patients and healthcare workers face a potentially greater risk of contracting HAIs due to the invasive nature of such procedures. Although not exhaustive, we attempted through a literature search to provide a general overview of infection prevention and control practices, address HAIs in the radiology departments, and highlight the challenges and measures taken to control infection transmission in the radiology departments.

Drug Resistance Mechanism of Enterobacteriaceae with Decreased Antibiotic Sensitivity

To investigate the mechanism of antibiotic resistance in Enterobacteriaceae. Carbapenem Enterobacteriaceae bacteria isolated from a hospital from January 2015 to June 2020 were selected. Drug resistance phenotype test, drug sensitivity test, and conjugation test were used to observe the drug sensitivity results and the titer of acrB antibody. Finally, the data were statistically analyzed. All strains were resistant to ceftazidime, ceftriaxone, ertapenem, and aztreonam. 87.5% of the samples were resistant to piperacillin. Multisite sequence typing showed that 5 carbapenem-resistant Klebsiella pneumoniae belonged to 4 different types. The sequence types of kpn6099 and kpn6617 were the same. In the sensitivity comparison, Escherichia coli J53 was more sensitive to these two antibiotics, minimum inhibitory concentration values were 0.5 and 0.25 μg/ml, respectively. In addition, the sensitivity of E. coli J53 to carbapenems was slightly higher than that of kpn6617. The results showed that the enzyme-linked immunosorbent assay titer of acrB antibody was 1:40,000, and the preparation of acrB antibody was successful. Plasmid-mediated deletion of IMP-1 metallo-β-lactamase binding outer membrane protein is one of the main reasons for the decrease of antibiotic sensitivity.

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.

Correlation Between the Number of Fiberoptic Bronchoscopies and Nosocomial Infection/Colonization of Carbapenem-Resistant Enterobacteriaceae

Objective

The present study aims to explore the effects of different numbers of fiberoptic bronchoscopic examinations on the nosocomial infection/colonization of carbapenem-resistant Enterobacteriaceae (CRE).

Methods

The data of 129 patients admitted to the intensive care unit of a grade 3A hospital were retrospectively analyzed, and CRE nosocomial infection/colonization situations in patients with fiberoptic bronchoscope application times of 1, 2, 3, and ≥4 were statistically analyzed.

Results

The incidence of nosocomial infection/colonization of CRE increased significantly when the number of fiberoptic bronchoscopic examinations was ≥3.

Conclusion

Nosocomial infection/colonization of CRE is highly correlated with an increased number of fiberoptic bronchoscopic examinations.

Cost utility analysis of strategies for minimizing risk of duodenoscope-related infections

BACKGROUND AND AIMS

Transmission of multidrug-resistant organisms by duodenoscopes during ERCP is problematical. The U.S. Food and Drug Administration recently recommended transitioning away from reusable fixed-endcap duodenoscopes to those with innovative device designs that make reprocessing easier, more effective, or unnecessary. Partially disposable (PD) duodenoscopes with disposable endcaps and fully disposable (FD) duodenoscopes are now available. We assessed the relative cost of approaches to minimizing infection transmission, taking into account duodenoscope-transmitted infection cost.

METHODS

We developed a Monte Carlo analysis model in R (R Foundation for Statistical Computing, Vienna, Austria) with a multistate trial framework to assess the cost utility of various approaches: single high-level disinfection (HLD), double HLD, ethylene oxide (EtO) sterilization, culture and hold, PD duodenoscopes, and FD duodenoscopes. We simulated quality-adjusted life years (QALYs) lost by duodenoscope-transmitted infection and factored this into the average cost for each approach.

RESULTS

At infection transmission rates <1%, PD duodenoscopes were most favorable from a cost utility standpoint in our base model. The FD duodenoscope minimizes the potential for infection transmission and is more favorable from a cost utility standpoint than use of reprocessable duodenoscopes after single or double HLD at all infection rates, EtO sterilization for infection rates >.32%, and culture and hold for infection rates >.56%. Accounting for alternate scenarios of variation in hospital volume, QALY value, post-ERCP lifespan, and environmental cost shifted cost utility profiles.

CONCLUSIONS

Our model indicates that PD duodenoscopes represent the most favorable option from a cost utility standpoint for ERCP, with anticipated very low infection transmission rates and a low-cost disposable element. These data underscore the importance of cost calculations that account for the potential for infection transmission and associated patient morbidity/mortality.

Multidrug-Resistant Gram-Negative Bacteria: Infection Prevention and Control Update

Multidrug-resistant gram-negative bacteria (MDR-GNB) pose one of the greatest challenges to health care today because of their propensity for human-to-human transmission and lack of therapeutic options. Containing the spread of MDR-GNB is challenging, and the application of multifaceted infection control bundles during an evolving outbreak makes it difficult to measure the relative impact of each measure. This article will review the utility of various infection control measures in containing the spread of various MDR-GNB and will provide the supporting evidence for these interventions.

Gastrointestinal and hepatic diseases during the COVID-19 pandemic: Manifestations, mechanism and management

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is considered the causative pathogen of coronavirus disease 2019 (COVID-19) and has become an international danger to human health. Although respiratory transmission and symptoms are still the essential manifestations of COVID-19, the digestive system could be an unconventional or supplementary route for COVID-19 to be transmitted and manifested, most likely due to the presence of angiotensin-converting enzyme 2 (ACE2) in the gastrointestinal tract. In addition, SARS-CoV-2 can trigger hepatic injury via direct binding to the ACE2 receptor in cholangiocytes, antibody-dependent enhancement of infection, systemic inflammatory response syndrome, inflammatory cytokine storms, ischemia/reperfusion injury, and adverse events of treatment drugs. Gastrointestinal symptoms, including anorexia, nausea, vomiting, and diarrhea, which are unusual in patients with COVID-19, and some digestive signs may occur without other respiratory symptoms. Furthermore, SARS-CoV-2 can be found in infected patients' stool, demonstrating the likelihood of transmission through the fecal-oral route. In addition, liver function should be monitored during COVID-19, particularly in more severe cases. This review summarizes the evidence for extra-pulmonary manifestations, mechanisms, and management of COVID-19, particularly those related to the gastrointestinal tract and liver.

Targeted Molecular Detection of Nosocomial Carbapenemase-Producing Gram-Negative Bacteria-On Near- and Distant-Patient Surfaces

Background: Here, we describe an integrative method to detect carbapenemase-producing Gram-negative bacteria (gn-Cp) on surfaces/fomites in the patient environment. We examined environmental samples from 28 patient rooms occupied with patients who were proven to be colonised with gn-Cp by rectal screening. Methods: We took samples after 24 h, 72 h and one week. For sampling, we divided the patient environment into four parts and took samples from near- and extended patient areas. To obtain a representative bacterial swab from a larger surface, such as the patient cabinet, we used Polywipes. Bacterial DNA was isolated. Carbapenemase was detected with specific qPCR primers. Results: With this culture- and molecular-based approach, we could control the effectiveness of cleaning and disinfection in everyday clinical practice. Therefore, we could track the spread of gn-Cp within the patient room. The number of positive detections fluctuated between 30.5% (mean value positive results after 72 h) and 35.2% (after 24 h and one week). Conclusion: The method used to detect multidrug-resistant bacteria in the environment of patients by using Polywipes^TM is reliable and can therefore be used as an effective, new tool in hygiene and infection control.

Device profile of the EXALT Model D single-use duodenoscope for endoscopic retrograde cholangiopancreatography: overview of its safety and efficacy

Introduction: The management of pancreaticobiliary disorders relies heavily on endoscopic retrograde cholangiopancreatography, which is performed with a duodenoscope. Bacterial colonization of reusable duodenoscopes leading to subsequent infectious outbreaks is well recognized and remains an issue despite efforts to optimize best practices in high-level disinfection. The EXALT Model D duodenoscope (EXALT) (Boston Scientific Corporation, Marlborough, MA) is a single-use device, designed to achieve technical equivalency with reusable devices while eliminating the potential for device-related outbreaks.Areas covered: This review covers the challenges associated with reprocessing duodenoscopes and the development of duodenoscope-related infections, with an emphasis on the use of single-use duodenoscopes as a potential solution to this issue.Expert Opinion: Duodenoscope-related infections are an increasingly recognized problem. Infectious outbreaks harm patients, significantly affect providers and medical centers, and can erode patient trust in the health-care system. Single-use duodenoscopes eliminate both the risk of device-related infection transmission and the need for burdensome duodenoscope reprocessing. In clinical evaluations, the EXALT device has demonstrated an equivalent technical performance and provider satisfaction compared to reusable duodenoscopes. Increasing use of this device will clarify how it compares to reusable duodenoscopes in a variety of clinical settings among endoscopists of varying skills levels.

Risk Factors for Intra-Abdominal Infections Caused by Carbapenemase-Producing Enterobacteriaceae in a Surgical Setting

Background: The aim of this study was to identify risk factors for acquisition of intra-abdominal infections (IAI) caused by carbapenemase-producing Enterobacteriaceae (CPE) in surgical patients. Methods: A matched case-control study was performed. We included all cases with CPE-related IAI acquired during admission to a general surgery department from January 2013 to December 2018, and they were matched with control subjects with IAI caused by non-resistant bacteria (ratio 1:3). Independent risk factors were obtained by logistic regression. Results: Forty patients with IAI-CPE were matched with 120 control subjects. Independent risk factors for acquisition of IAI-CPE were previous hospitalization (odds ratio [OR] 2.56; 95% confidence interval [CI] l 1.01-6.49; p = 0.047), digestive endoscopy (OR 4.11; 95% CI 1.40-12.07; p = 0.010), carbapenem therapy (OR 9.54; 95% CI 3.33-27.30; p < 0.001), and aminoglycoside use (OR 45.41; 95% CI 7.90-261.06; p < 0.001). Conclusions: Four clinical factors can identify patients at high-risk of IAI-CPE.

Improving the Reprocessing Quality of Flexible Thermolabile Endoscopes: How to Learn from Mistakes

Background: Failure in the reprocessing of thermolabile flexible endoscopes has been reported as one of the most important threats to patient health. Method: A case report and observational study was conducted, from August 2014 to December 2019, in the Digestive Endoscopy Unit of a University Hospital in Italy, where two cases of Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae infections in patients undergoing endoscopic retrograde cholangio-pancreatography were observed. Following the risk/safety management practices, an epidemiological investigation was started, duodenoscopes were removed from use and the reprocessing practices reviewed. Moreover, microbiological surveillance of endoscopes was carried out according to the CDC guidelines. Results: In the first phase of sampling, 10/10 (100%) endoscopes were found to be non-compliant, of which 7 showed results for high-concern organisms (HCOs), such as KPC-K. pneumoniae, P. aeruginosa and E. coli. After implementing corrective actions, 12 out of 17 endoscopes were found to be non-compliant (70.5%), of which 8 showed results for HCOs, such as KPC-K. oxytoca and P. aeruginosa. During the last year of regular microbiological surveillance, only 23% of endoscopes (35/152) were found to be non-compliant, of which 7 showed results for HCOs, such as NDM-K. pneumoniae, P. aeruginosa and A. baumannii. The crucial issues were related to samples collected from the internal channels of duodenoscopes. Conclusion: Managing the risk associated with the reprocessing of digestive endoscopes, through risk assessment at every stage of the process, is important for the prevention of infections associated with the use of these device.

Evolution in the Practice of Pediatric Endoscopy and Sedation

The fields of pediatric gastrointestinal endoscopy and sedation are critically important to the diagnosis and treatment of gastrointestinal (GI) disease in children. Since its inception in the 1970s, pediatric endoscopy has benefitted from tremendous technological innovation related to the design of the endoscope and its associated equipment. Not only that, but expertise among pediatric gastroenterologists has moved the field forward to include a full complement of diagnostic and therapeutic endoscopic procedures in children. In this review, we discuss the remarkable history of pediatric endoscopy and highlight current limitations and future advances in the practice and technology of pediatric endoscopy and sedation.

The Effectiveness of Drying on Residual Droplets, Microorganisms, and Biofilms in Gastrointestinal Endoscope Reprocessing: A Systematic Review

BACKGROUND

Despite endoscope reprocessing, residual droplets remain in gastrointestinal endoscope working channels. Inadequate drying of gastrointestinal endoscope working channels may promote microbial reproduction and biofilm formation, increasing the risk of infection in patients. This review was designed to provide the current status of gastrointestinal endoscope drying, emphasize the importance of gastrointestinal endoscope drying, and evaluate the effectiveness of different drying methods of gastrointestinal endoscope in reducing residual droplets and microbial growth risk.

METHODS

A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting checklist. The PubMed, Web of Science, Medline, EMBASE, EBSCO, CNKI, CQVIP, and Wanfang Data databases were searched from 2010 to 2020 to identify eligible articles focused on methods of gastrointestinal endoscope drying and the status of endoscope drying. The following key points were analyzed: type of intervention, amount of residual droplets, major microbial types, and effectiveness of biofilm intervention. JBI quality assessment tool was used to determine bias risk for inclusion in the article.

RESULTS

This review included twelve articles. Two of the articles reported lack of drying of gastrointestinal endoscopes while the other ten reported residual droplets, microbial growth, and biofilm formation after different methods of drying. Four articles reported 0 to 4.55 residual droplets; four articles reported that the main microbial types were cocci and bacilli, most commonly Staphylococcus, Escherichia coli, Bacillus maltophilia, and Pseudomonas aeruginosa; and two reported that drying could effectively reduce biofilm regeneration. The type of intervention is as follows: automatic endoscopy reprocessor (AER), manual compressed air drying, and the Dri-Scope Aid for automatic drying and drying cabinet.

CONCLUSIONS

While endoscope reprocessing may not always be effective, an automatic endoscope reprocessor plus the Dri-Scope Aid with automatic drying over 10 min or storage in a drying cabinet for 72 h may be preferred.

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.

Nationwide risk analysis of duodenoscope and linear echoendoscope contamination

BACKGROUND AND AIMS

Contaminated duodenoscopes and linear echoendoscopes (DLEs) pose a risk for infectious outbreaks. To identify DLEs and reprocessing risk factors, we combined the data from the previously published nationwide cross-sectional PROCESS 1 study (Prevalence of contamination of complex endoscopes in the Netherlands) with the follow-up PROCESS 2 study.

METHODS

We invited all 74 Dutch DLE centers to sample ≥2 duodenoscopes during PROCESS 1, and all duodenoscopes as well as linear echoendoscopes during PROCESS 2. The studies took place 1 year after another. Local staff sampled each DLE at ≤6 sites according to uniform methods explained by online videos. We used 2 contamination definitions: (1) any microorganism with ≥20 colony-forming units (CFU)/20 mL (AM20) and (2) presence of microorganisms with GI or oral origin, independent of CFU count (MGOs). We assessed the factors of age and usage by performing an analysis of pooled data of both PROCESS studies; additional factors including reprocessing characteristics were only recorded in PROCESS 2.

RESULTS

Ninety-seven percent of all Dutch centers (72 of 74; PROCESS 1, 66; PROCESS 2, 61) participated in one of the studies, sampling 309 duodenoscopes and 64 linear echoendoscopes. In total, 54 (17%) duodenoscopes and 8 (13%) linear echoendoscopes were contaminated according to the AM20 definition. MGOs were detected on 47 (15%) duodenoscopes and 9 (14%) linear echoendoscopes. Contamination was not age or usage dependent (all P values ≥.27) and was not shown to differ between the reprocessing characteristics (all P values ≥.01).

CONCLUSIONS

In these nationwide studies, we found that DLE contamination was independent of age and usage. These results suggest that old and heavily used DLEs, if maintained correctly, have a similar risk for contamination as new DLEs. The prevalence of MGO contamination of ∼15% was similarly high for duodenoscopes as for linear echoendoscopes, rendering patients undergoing ERCP and EUS at risk for transmission of microorganisms.

Clinical Evaluation of a Single-Use Duodenoscope for Endoscopic Retrograde Cholangiopancreatography

BACKGROUND & AIMS

Disposable, single-use duodenoscopes might reduce outbreaks of infections associated with endoscope reuse. We tested the feasibility, preliminary safety, and performance of a new single-use duodenoscope in patients undergoing endoscopic retrograde cholangiopancreatography (ERCP).

METHODS

We conducted a case-series study of the outcomes of ERCP with a single-use duodenoscope from April through May 2019 at 6 academic medical centers. We screened consecutive patients (18 years and older) without alterations in pancreaticobiliary anatomy and enrolled 73 patients into the study. Seven expert endoscopists performed roll-in maneuvers (duodenoscope navigation and visualization of duodenal papilla only) in 13 patients and then ERCPs in the 60 other patients. Outcomes analyzed included completion of ERCP for the intended clinical indication, crossover from a single-use duodenoscope to a reusable duodenoscope, endoscopist performance ratings of the device, and serious adverse events (assessed at 72 hours and 7 days).

RESULTS

Thirteen (100%) roll-in maneuver cases were completed using the single-use duodenoscope. ERCPs were of American Society for Gastrointestinal Endoscopy procedural complexity grade 1 (least complex; 7 patients [11.7%]), grade 2 (26 patients [43.3%]), grade 3 (26 patients [43.3%]), and grade 4 (most complex; 1 patient [1.7%]). Fifty-eight ERCPs (96.7%) were completed using the single-use duodenoscope only and 2 ERCPs (3.3%) were completed using the single-use duodenoscope followed by crossover to a reusable duodenoscope. Median overall satisfaction was 9 out of 10. Three patients developed post-ERCP pancreatitis, 1 patient had post-sphincterotomy bleeding, and 1 patient had worsening of a preexisting infection and required rehospitalization.

CONCLUSIONS

In a case-series study, we found that expert endoscopists can complete ERCPs of a wide range of complexity using a single-use duodenoscope for nearly all cases. This alternative might decrease ERCP-related risk of infection. Clinicaltrials.gov no: NCT03701958.

COVID-19 and gastrointestinal endoscopies: Current insights and emergent strategies

A new coronavirus emerged in December 2019 in Wuhan city of China, named as the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), and the disease was called coronavirus disease-2019 (COVID-19). The infection due to this virus spread exponentially throughout China and then spread across >205 nations, including the United States (US). Gastrointestinal (GI) endoscopies are routinely performed in the US and globally. Previous reports of isolated infection outbreaks were reported with endoscopes acting as potential vectors. While multidrug-resistant organisms have been reported to be spread by endoscopes, few cases of viruses such as hepatitis B and C are noted in the literature. COVID-19 is predominately spread by droplet transmission, although recent evidence has showed that shedding in feces and feco-oral transmission could also be possible. It is unclear if COVID-19 could be transmitted by endoscopes, but it could theoretically happen due to contact with mucous membranes and body fluids. GI endoscopies involve close contact with oral and colonic contents exposing endoscopy staff to respiratory and oropharyngeal secretions. This can increase the risk of contamination and contribute to virus transmission. Given these risks, all major GI societies have called for rescheduling elective non-urgent procedures and perform only emergent or urgent procedures based on the clinical need. Furthermore, pre-screening of all individuals prior to endoscopy is recommended. This article focuses on the risk of COVID-19 transmission by GI shedding, the potential role of endoscopes as a vector of this novel virus, including transmission during endoscopies, and prevention strategies including deferral of elective non-urgent endoscopy procedures.

Dual-Functional, Superhydrophobic Coatings with Bacterial Anticontact and Antimicrobial Characteristics

Bacterial pathogens are responsible for millions of cases of illnesses and deaths each year throughout the world. The development of novel surfaces and coatings that effectively inhibit and prevent bacterial attachment, proliferation, and growth is one of the crucial steps for tackling this global challenge. Herein, we report a dual-functional coating for aluminum surfaces that relies on the controlled immobilization of lysozyme enzyme (muramidase) into interstitial spaces of presintered, nanostructured thin film based on ∼200 nm silica nanoparticles and the sequential chemisorption of an organofluorosilane to the available interfacial areas. The mean diameter of the resultant lysozyme microdomains was 3.1 ± 2.5 μm with an average spacing of 8.01 ± 6.8 μm, leading to a surface coverage of 15.32%. The coating had an overall root-mean-square (rms) roughness of 539 ± 137 nm and roughness factor of 1.50 ± 0.1, and demonstrated static, advancing, and receding water contact angles of 159.0 ± 1.0°, 155.4 ± 0.6°, and 154.4 ± 0.6°, respectively. Compared to the planar aluminum, the coated surfaces produced a 6.5 ± 0.1 (>99.99997%) and 4.0 ± 0.1 (>99.99%) log-cycle reductions in bacterial surfaces colonization against Gram-negative Salmonella Typhimurium LT2 and Gram-positive Listeria innocua, respectively. We anticipate that the implementation of such a coating strategy on healthcare environments and surfaces and food-contact surfaces can significantly reduce or eliminate potential risks associated with various contamination and cross-contamination scenarios.

Multidisciplinary and Multisociety Practice Guideline on Reprocessing Flexible Gastrointestinal Endoscopes and Endoscopic Accessories

The area of endoscopic application has been continuously expanded since its introduction in the last century and the frequency of its use also increased stiffly in the last decades. Because gastrointestinal endoscopy is naturally exposed to diseased internal organs and contact with pathogenic materials, endoscopy mediated infection or disease transmission becomes a major concern in this field. Gastrointestinal endoscopy is not for single use and the proper reprocessing process is a critical factor for safe and reliable endoscopy procedures. What needed in these circumstances is a practical guideline for reprocessing the endoscope and its accessories which is feasible in the real clinical field to guarantee acceptable prevention of pathogen transmission. This guideline contains principles and instructions of the reprocessing procedure according to the step by step. And it newly includes general information and updated knowledge about endoscopy-mediated infection and disinfection. Multiple societies and working groups participated to revise; Korean Association for the Study of the Liver, the Korean Society of Infectious Diseases, Korean College of Helicobacter and Upper Gastrointestinal Research, the Korean Society of Gastroenterology, Korean Society of Gastrointestinal Cancer, Korean Association for the Study of Intestinal Diseases, Korean Pancreatobiliary Association, the Korean Society of Gastrointestinal Endoscopy Nurses and Associates and Korean Society of Gastrointestinal Endoscopy. Through this cooperation, we enhanced communication and established a better concordance. We still need more researches in this field and fill up the unproven area. And our guidelines will be renewed accordingly.

Impact of wet storage and other factors on biofilm formation and contamination of patient-ready endoscopes: a narrative review

The 2019 U.S. Food and Drug Administration report indicates that the clinical studies undertaken by the 3 main GI endoscope manufacturers demonstrate 5.4% of patient-ready duodenoscopes remain culture positive for high-concern organisms. The root causes of this persistent contamination are poorly understood. The objectives of this review include summarizing (1) the impact of inadequate manual cleaning and inadequate drying during storage on the formation of build-up biofilm in endoscope channels, (2) the impact of defoaming agents used during patient procedures on drying efficacy, (3) the data showing the importance of build-up biofilm on persistent microbial survival, and (4) the potential impact of implementation of a quality systems approach in GI endoscopy reprocessing.

Novel single-use duodenoscope compared with 3 models of reusable duodenoscopes for ERCP: a randomized bench-model comparison

BACKGROUND AND AIMS

Multidrug-resistant infectious outbreaks associated with duodenoscope reuse have been documented internationally. A single-use endoscope could eliminate exogenous patient-to-patient infection associated with ERCP.

METHODS

We conducted a comparative bench simulation study of a new single-use and 3 models of reusable duodenoscopes on a synthetic anatomic bench model. Four ERCP tasks were performed: guidewire locking (single-use and 1 reusable duodenoscope only), plastic stent placement and removal, metal stent placement and removal, and basket sweeping. The study schedule included block randomization by 4 duodenoscopes, 4 tasks, and 2 anatomic model ERCP stations. Ability to complete tasks, task completion times, and subjective ratings of overall performance, navigation/pushability, tip control, and image quality on a scale of 1 (worst) to 10 (best) were compared among duodenoscopes.

RESULTS

All 4 ERCP tasks (total 14 subtasks) were completed by 6 expert endoscopists using all 4 duodenoscopes, with similar task completion times (median, 1.5-8.0 minutes per task) and overall performance ratings by task (median, 8.0-10.0). Navigation/pushability ratings were lower for the single-use duodenoscope than for the 3 reusable duodenoscopes (median, 8.0, 10.0, 9.0, and 9.0, respectively; P < .01). Tip control ratings were similar among all the duodenoscopes (median, 9.0-10.0; P = .77). Image quality ratings were lower for 1 reusable duodenoscope compared with the single-use and other 2 reusable duodenoscopes (median, 8.0, 9.0, 9.0, and 9.0, respectively; P < .01).

CONCLUSIONS

A new single-use duodenoscope was used to simulate 4 ERCP tasks in an anatomic model, with performance ratings and completion times comparable with 3 models of reusable duodenoscopes.

Endoscopic Retrograde Cholangiopancreatography-Related Complications and Their Management Strategies: A "Scoping" Literature Review

Endoscopic retrograde cholangiopancreatography (ERCP) is a well-known procedure with both diagnostic and therapeutic utilities in managing pancreaticobiliary conditions. With the advancements of endoscopic techniques, ERCP has become a relatively safe and effective procedure. However, as ERCP is increasingly being utilized for different advanced techniques, newer complications have been noticed. Post-ERCP complications are known, and mostly include pancreatitis, infection, hemorrhage, and perforation. The risks of these complications vary depending on several factors, such as patient selection, endoscopist's skills, and the difficulties involved during the procedure. This review discusses post-ERCP complications and management strategies with new and evolving concepts.

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.

Independent root-cause analysis of contributing factors, including dismantling of 2 duodenoscopes, to investigate an outbreak of multidrug-resistant Klebsiella pneumoniae

BACKGROUND AND AIMS

Worldwide, an increasing number of duodenoscope-associated outbreaks are reported. The high prevalence rate of contaminated duodenoscopes puts patients undergoing ERCP at risk of exogenous transmission of microorganisms. The contributing factors of the duodenoscope design to contamination are not well understood. This article reports on the investigation after the outbreak of a multidrug-resistant Klebsiella pneumoniae (MRKP) related to 2 Olympus TJF-Q180V duodenoscopes.

METHODS

We conducted a contact patient screening and microbiologic laboratory database search. Reprocessing procedures were audited, and both duodenoscopes were fully dismantled to evaluate all potential contamination factors. Outcomes were reviewed by an experienced independent expert.

RESULTS

In total, 102 patients who had undergone an ERCP procedure from January to August 2015 were invited for screening. Cultures were available of 81 patients, yielding 27 MRKP-infected or -colonized patients. Ten patients developed an MRKP-related active infection. The 2 duodenoscopes had attack rates (the number of infected or colonized cases/number of exposed persons) of 35% (17/49) and 29% (7/24), respectively. Identical MRKP isolates were cultured from channel flushes of both duodenoscopes. The review revealed 4 major abnormalities: miscommunication about reprocessing, undetected damaged parts, inadequate repair of duodenoscope damage, and duodenoscope design abnormalities, including the forceps elevator, elevator lever, and instrumentation port sealing.

CONCLUSIONS

Outbreaks are associated with a combination of factors, including duodenoscope design issues, repair issues, improper cleaning, and systemic monitoring of contamination. To eliminate future duodenoscope-associated infections, a multipronged approach is required, including clear communication by all parties involved, a reliable servicing market, stringent surveillance measures, and eventually new duodenoscope designs and reprocessing procedures with a larger margin of safety.

Endoscope reprocessing: Comparison of drying effectiveness and microbial levels with an automated drying and storage cabinet with forced filtered air and a standard storage cabinet

BACKGROUND

Automated drying may help prevent endoscopically transmitted infections. We aimed to assess the efficacy of an automated drying and storage cabinet compared to a standard storage cabinet in achieving endoscope dryness postreprocessing and in reducing the risk of microbial growth.

METHODS

Drying times of bronchoscopes, colonoscopes, and duodenoscopes using 2 drying platforms (an automated drying and storage cabinet vs a standard storage cabinet) were measured using cobalt chloride paper. Drying assessments occurred at: 30 minutes, 1 hour, 2 hours, 3 hours, and 24 hours. A simple linear regression analysis compared rates of microbial growth after inoculation with Pseudomonas aeruginosa following high-level disinfection at: 0, 3 hours, 12 hours, 24 hours, and 48 hours.

RESULTS

Using the automated drying and storage cabinet, internal channels were dry at 1 hour and external surfaces at 3 hours in all endoscopes. With the standard storage cabinet, there was residual internal fluid at 24 hours, whereas external surfaces were dry at 24 hours. For bronchoscopes, colonoscopes, and duodenoscopes, the standard cabinet allowed for an average rate of colony forming unit growth of 8.1 × 10⁶ per hour, 8.3 × 10⁶ per hour, and 7.0 × 10⁷ per hour, respectively; the automated cabinet resulted in colony forming unit growth at an average rate of -28.4 per hour (P = .02), -38.5 per hour (P = .01), and -200.2 per hour (P = .02), respectively.

CONCLUSIONS

An automated cabinet is advantageous for rapid drying of endoscope surfaces and in reducing the risk of microbial growth postreprocessing.

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).

Duodenoscope-Associated Infections: Update on an Emerging Problem

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

Disinfection, sterilization, and antisepsis: An overview

All invasive procedures involve contact by a medical device or surgical instrument with a patient's sterile tissue or mucous membranes. The level of disinfection or sterilization is dependent on the intended use of the object. Critical (items that contact sterile tissue, such as surgical instruments), semicritical (items that contact mucous membranes, such as endoscopes), and noncritical (devices that contact only intact skin, such as stethoscopes) items require sterilization, high-level disinfection, and low-level disinfection, respectively. Cleaning must always precede high-level disinfection and sterilization. Antiseptics are essential to infection prevention as part of a hand hygiene program, as well as other uses, such as surgical hand antisepsis and preoperative skin preparation.

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.

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.

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 test method to assess the contribution of fluid shear stress to the cleaning of reusable device surfaces

Adequate cleaning of reusable medical devices is critical for preventing cross-infection among patients. For reusable medical devices, cleaning using mechanical brushes and detergent may not be sufficient to completely remove the infectious contaminants from the surfaces. This study evaluates the role of fluid flow-induced shear stress in the detachment and removal of contaminants from device surfaces. A stainless-steel test coupon, acting as a surrogate for a device surface, was coated with artificial clot of varying mass. The test coupon was exposed to fluid shear stress both with and without an enzymatic detergent. The relationship between clot removal quantity and the applied shear stress was obtained for multiple clot masses. Our results showed that fluid shear increased the effectiveness of the cleaning process. In the absence of flow, soaking the clot surface in the enzymatic detergent removed 67%, 77%, and 95% of the clot for 16 mg, 6.8 mg, and 1 mg initial masses, respectively. In the presence of fluid shear (0.3 Pa for 5 min), approximately 85%, 97%, and 99% of the clot was removed from the surface. The clot mass removed followed a linear relationship (R² = 0.98) versus the applied fluid shear stress. This study showed that different cleaning processes such as fluid shear and detergent action contribute to the soil removal process. This method could be used to evaluate cleaning protocols for minimizing contaminant residue after the reprocessing of medical devices. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1132-1140, 2019.

High prevalence rate of digestive tract bacteria in duodenoscopes: a nationwide study

OBJECTIVE

Increasing numbers of outbreaks caused by contaminated duodenoscopes used for Endoscopic Retrograde Cholangiopancreatography (ERCP) procedures have been reported, some with fatal outcomes. We conducted a nationwide cross-sectional study to determine the prevalence of bacterial contamination of reprocessed duodenoscopes in The Netherlands.

DESIGN

All 73 Dutch ERCP centres were invited to sample ≥2 duodenoscopes using centrally distributed kits according to uniform sampling methods, explained by video instructions. Depending on duodenoscope type, four to six sites were sampled and centrally cultured. Contamination was defined as (1) any microorganism with ≥20 colony forming units (CFU)/20 mL (AM20) and (2) presence of microorganisms with gastrointestinal or oral origin, independent of CFU count (MGO).

RESULTS

Sixty-seven out of 73 centres (92%) sampled 745 sites of 155 duodenoscopes. Ten different duodenoscope types from three distinct manufacturers were sampled including 69 (46%) Olympus TJF-Q180V, 43 (29%) Olympus TJF-160VR, 11 (7%) Pentax ED34-i10T, 8 (5%) Pentax ED-3490TK and 5 (3%) Fujifilm ED-530XT8. Thirty-three (22%) duodenoscopes from 26 (39%) centres were contaminated (AM20). On 23 (15%) duodenoscopes MGO were detected, including Enterobacter cloacae, Escherichia coli, Klebsiella pneumonia and yeasts. For both definitions, contamination was not duodenoscope type dependent (p values: 0.20 and higher).

CONCLUSION

In 39% of all Dutch ERCP centres, at least one AM20-contaminated patient-ready duodenoscope was identified. Fifteen per cent of the duodenoscopes harboured MGO, indicating residual organic material of previous patients, that is, failing of disinfection. These results suggest that the present reprocessing and process control procedures are not adequate and safe.

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.

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

BACKGROUND

Bacterial culture is the accepted standard to measure the adequacy of high-level disinfection (HLD) of duodenoscopes. Adenosine triphosphate (ATP) bioluminescence assays have been suggested as an alternative method of evaluating the quality of reprocessing. We systematically reviewed published research describing the correlation between ATP and bacterial cultures.

METHODS

The primary outcome was the correlation or concordance between concomitantly sampled ATP and bacterial contamination obtained from the instrument channel and/or elevator mechanism of the duodenoscope. A secondary outcome included the reduction in ATP measurements between paired samples before and after stages of duodenoscope reprocessing.

RESULTS

Ten studies were included in the analysis. Four studies reported the relationship between concomitantly sampled ATP and cultures. Three studies reported receiver operating characteristic curves (1 study additionally reported a Wilcoxon rank sum test), and 1 study reported Spearman correlation coefficients and paired dichotomous measurements of ATP and bacterial contamination. All analyses suggested a poor relationship between the 2 measures. Studies measuring ATP before and after manual cleaning and before and after HLD reported a reduction in ATP after the reprocessing stage.

CONCLUSION

Current research does not support the direct substitution of ATP for bacterial culture surveillance of duodenoscopes. Serial ATP measurement may be a useful tool to evaluate the adequacy of manual cleaning and for training of endoscopic reprocessing staff.

The Role of Patient Care Items as a Fomite in Healthcare-Associated Outbreaks and Infection Prevention

Patient-care items can serve as a source or reservoir for healthcare-associated pathogens in hospitals. We reviewed healthcare- associated outbreaks from medical equipment and provide infection prevention recommendations. Multiple healthcare-associated outbreaks via a contaminated patient-care item were identified, including infections with multidrug-resistant organisms. The type of patient care items implicated as a fomite causing healthcare-associated infections (HAIs) has changed over time. Patient populations at risk were most commonly critically ill patients in adult and neonatal intensive care units. Most fomite related healthcare-associated outbreaks were due to inappropriate disinfection practices. Repeated healthcare-associated outbreaks via medical equipment highlight the need for infectious disease professionals to understand that fomites/medical devices may be a source of HAIs. The introduction of new and more complex medical devices will likely increase the risk that such devices serve as a source of HAIs. Assuring appropriate cleaning and disinfection or sterilization of medical equipment is necessary to prevent future fomite-associated outbreaks.

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

BACKGROUND AND AIMS

Duodenoscopes have been implicated in the transmission of multidrug-resistant organisms (MDRO). We compared the frequency of duodenoscope contamination with MDRO or any other bacteria after disinfection or sterilization by 3 different methods.

METHODS

We performed a single-center prospective randomized study in which duodenoscopes were randomly reprocessed by standard high-level disinfection (sHLD), double high-level disinfection (dHLD), or standard high-level disinfection followed by ethylene oxide gas sterilization (HLD/ETO). Samples were collected from the elevator mechanism and working channel of each duodenoscope and cultured before use. The primary outcome was the proportion of duodenoscopes with an elevator mechanism or working channel culture showing 1 or more MDRO; secondary outcomes included the frequency of duodenoscope contamination with more than 0 and 10 or more colony-forming units (CFU) of aerobic bacterial growth on either sampling location.

RESULTS

After 3 months of enrollment, the study was closed because of the futility; we did not observe sufficient events to evaluate the primary outcome. Among 541 duodenoscope culture events, 516 were included in the final analysis. No duodenoscope culture in any group was positive for MDRO. Bacterial growth of more than 0 CFU was noted in 16.1% duodenoscopes in the sHLD group, 16.0% in the dHLD group, and 22.5% in the HLD/ETO group (P = .21). Bacterial growth or 10 or more CFU was noted in 2.3% of duodenoscopes in the sHLD group, 4.1% in the dHLD group, and 4.2% in the HLD/ETO group (P = .36). MRDOs were cultured from 3.2% of pre-procedure rectal swabs and 2.5% of duodenal aspirates.

CONCLUSIONS

In a comparison of duodenoscopes reprocessed by sHLD, dHLD, or HLD/ETO, we found no significant differences between groups for MDRO or bacteria contamination. Enhanced disinfection methods (dHLD or HLD/ETO) did not provide additional protection against contamination. However, insufficient events occurred to assess our primary study end-point. ClinicalTrials.gov no: NCT02611648.