Withdrawal of a novel-design duodenoscope ends outbreak of a VIM-2-producing Pseudomonas aeruginosa

Acute cholangitis with Achromobacter xylosoxidans bacteremia after endoscopic retrograde cholangiopancreatography in hilar cholangiocarcinoma: A case report

BACKGROUND

Achromobacter xylosoxidans is a Gram-negative opportunistic aerobe, usually causing nosocomial infections in immunocompromised patients with manifestations including bacteremia, pneumonia, and catheter-related infections. However, A. xylosoxidans have not yet been reported to cause biliary system infections.

CASE SUMMARY

A 72-year-old woman presented to the outpatient department of our hospital with a chief complaint of jaundice. Computed tomography of her abdomen revealed the presence of a mass of approximately 2.4 cm in the hilar portion of the common hepatic duct, consistent with hilar cholangiocarcinoma. We performed endoscopic retrograde cholangiopancreatography (ERCP) to decompress the obstructed left and right intrahepatic ducts (IHDs) and placed 10 cm and 11 cm biliary stents in the left and right IHDs, respectively. However, the day after the procedure, the patient developed post-ERCP cholangitis as the length of the right IHD stent was insufficient for proper bile drainage. The blood culture of the patient tested positive for A. xylosoxidans. Management measures included the replacement of the right IHD stent (11 cm) with a longer one (12 cm) and administering culture-directed antibiotic therapy, solving the cholangitis-related complications. After the cholangitis had resolved, the patient underwent surgery for hilar cholangiocarcinoma and survived for 912 d without recurrence.

CONCLUSION

A. xylosoxidans-induced biliary system infections are extremely rare. Clinical awareness of physicians and endoscopists is required as this rare pathogen might cause infection after endoscopic procedures.

Endoscope sampling and culturing methods

BACKGROUND

Contamination rates reported in the literature for patient-ready flexible endoscopes vary from 0.4% to 49%. Unfortunately, the comparison and interpretation of these results is almost impossible since several factors including sampling and culturing methods, target levels for contamination, or definition of indicator micro-organisms vary widely from one study to the other.

AIM

To compare the efficacy of six duodenoscope sampling and culturing methods by means of extraction efficacy comparison, while at the same time identifying key parameters that provide optimal microbial recovery.

METHODS

The duodenoscope sample extraction efficacy of each method was assessed using the repetitive recovery method described in ISO 11737-1: 2018.

FINDINGS

Mean overall bioburden extraction efficacy varied from 1% for the Australian method to 39% for the French one. The lowest endoscope sample extraction efficacy was associated with the absence of any neutralizer, friction, or tensioactive agent, and when only a small portion of the sampling solution collected was inoculated on to culture media. The efficacy of the sampling and culturing methods also varied according to the nature of micro-organisms present in the endoscope, and the time between sampling and culturing.

CONCLUSION

This study supports the need for a harmonized and standardized sampling and culturing method for flexible endoscopes.

Uncovering the spread of drug-resistant bacteria through next-generation sequencing based surveillance: transmission of extended-spectrum β-lactamase-producing Enterobacterales by a contaminated duodenoscope

Contamination of duodenoscopes is a significant concern due to the transmission of multidrug-resistant organisms (MDROs) among patients who undergo endoscopic retrograde cholangiopancreatography (ERCP), resulting in outbreaks worldwide. In July 2020, it was determined that three different patients, all had undergone ERCP with the same duodenoscope, were infected. Two patients were infected with blaCTX-M-15 encoding Citrobacter freundii, one experiencing a bloodstream infection and the other a urinary tract infection, while another patient had a bloodstream infection caused by blaSHV-12 encoding Klebsiella pneumoniae. Molecular characterization of isolates was available as every ESBL-producing isolate undergoes Next-Generation Sequencing (NGS) for comprehensive genomic analysis in our center. After withdrawing the suspected duodenoscope, we initiated comprehensive epidemiological research, encompassing case investigations, along with a thorough duodenoscope investigation. Screening of patients who had undergone ERCP with the implicated duodenoscope, as well as a selection of hospitalized patients who had ERCP with a different duodenoscope during the outbreak period, led to the discovery of three additional cases of colonization in addition to the three infections initially detected. No microorganisms were detected in eight routine culture samples retrieved from the suspected duodenoscope. Only after destructive dismantling of the duodenoscope, the forceps elevator was found to be positive for blaSHV-12 encoding K. pneumoniae which was identical to the isolates detected in three patients. This study highlights the importance of using NGS to monitor the transmission of MDROs and demonstrates that standard cultures may fail to detect contaminated medical equipment such as duodenoscopes.

Unveiling 8 years of duodenoscope contamination: insights from a retrospective analysis in a large tertiary care hospital

OBJECTIVE

Contaminated duodenoscopes caused several hospital outbreaks. Despite efforts to reduce contamination rates, 15% of patient-ready duodenoscopes are still contaminated with gastrointestinal microorganisms. This study aimed to provide an overview of duodenoscope contamination over time, identify risk factors and study the effects of implemented interventions.

DESIGN

Duodenoscope culture sets between March 2015 and June 2022 at a Dutch tertiary care centre were analysed. Contamination was defined as (1) the presence of microorganisms of oral or gastrointestinal origin (MGO) or (2) any other microorganism with ≥20 colony-forming units/20 mL (AM20). A logistic mixed effects model was used to identify risk factors and assess the effect of interventions, such as using duodenoscopes with disposable caps, replacing automated endoscope reprocessors (AER) and conducting audits in the endoscopy department.

RESULTS

A total of 404 culture sets were analysed. The yearly contamination rate with MGO showed great variation, ranging from 14.3% to 47.5%. Contamination with AM20 increased up to 94.7% by 2022. For both MGO and AM20, the biopsy and suction channels were the most frequently contaminated duodenoscope components. The studied interventions, including audits, AER replacement and implementation of duodenoscopes with disposable caps, did not show a clear association with contamination rates.

CONCLUSION

Duodenoscope contamination remains a significant problem, with high contamination rates despite several interventions. Reprocessing the biopsy and suction channels is especially challenging. Changes in the design of reusable duodenoscopes, such as enabling sterilisation or easily replaceable channels, are necessary to facilitate effective duodenoscope reprocessing and to eliminate the risk of duodenoscope-associated infections.

The outcomes and safety of patients undergoing endoscopic retrograde cholangiopancreatography combining a single-use cholangioscope and a single-use duodenoscope: A multicenter retrospective international study

BACKGROUND

Duodenoscope-related multidrug-resistant organism (MDRO) infections raise concerns. Disposable duodenoscopes have been recently introduced in the market and approved by regulatory agencies with the aim to reduce the risk of endoscopic retrograde cholangiopancreatography (ERCP) associated infections. The aim of this study was to evaluate the outcome of procedures performed with single-use duodenoscopes in patients with clinical indications to single-operator cholangiopancreatoscopy.

METHODS

This is a multicenter international, retrospective study combining all patients who underwent complex biliopancreatic interventions using the combination of a single-use duodenoscope and a single-use cholangioscope. The primary outcome was technical success defined as ERCP completion for the intended clinical indication. Secondary outcomes were procedural duration, rate of cross-over to reusable duodenoscope, operator-reported satisfaction score (1 to 10) on performance rating of the single-use duodenoscope, and adverse event (AE) rate.

RESULTS

A total of 66 patients (26, 39.4% female) were included in the study. ERCP was categorized according to ASGE ERCP grading system as 47 (71.2%) grade 3 and 19 (28.8%) grade 4. The technical success rate was 98.5% (65/66). Procedural duration was 64 (interquartile range 15-189) min, cross-over rate to reusable duodenoscope was 1/66 (1.5%). The satisfaction score of the single-use duodenoscope classified by the operators was 8.6 ± 1.3 points. Four patients (6.1%) experienced AEs not directly related to the single-use duodenoscope, namely 2 post-ERCP pancreatitis (PEP), 1 cholangitis and 1 bleeding.

CONCLUSIONS

Single-use duodenoscope is effective, reliable and safe even in technically challenging procedures with a non-inferiority to reusable duodenoscope, making these devices a viable alternative to standard reusable equipment.

Pulling the plug on a pseudomonas outbreak: ancillary equipment as vectors of infection

OBJECTIVES

Outbreaks of infection related to flexible endoscopes are well described. However, flexible endoscopy also requires the use of ancillary equipment such as irrigation plugs. These are potential vectors of infection but are infrequently highlighted in the literature. This paper reports a cystoscopy-associated outbreak of Pseudomonas aeruginosa from contaminated irrigation plugs in a UK tertiary care centre.

METHODS

Laboratory, clinical and decontamination unit records were reviewed, and audits of the decontamination unit were performed. Flexible cystoscopes and irrigation plugs were assessed for contamination. Retrospective and prospective case finding was performed utilizing the microbiology laboratory information management system. Available P. aeruginosa isolates underwent variable nucleotide tandem repeat (VNTR) typing. Confirmed cases were defined as P. aeruginosa infection with an identical VNTR profile to an outbreak strain.

RESULTS

Three strains of P. aeruginosa were isolated from five irrigation plugs but none of the flexible cystoscopes. No acquired resistance mechanisms were detected. Fifteen confirmed infections occurred, including bacteraemia, septic arthritis and urinary tract infection. While failure of decontamination likely occurred because the plugs were not dismantled prior to reprocessing, the manufacturer's reprocessing instructions were also incompatible with standard UK practice. The Medicines and Healthcare Products Regulatory Agency was informed. A field safety notice was issued, and the manufacturer issued updated reprocessing instructions.

CONCLUSIONS

Ancillary equipment can represent an important vector for infection, and should be considered during outbreak investigations. Users should review the manufacturer's instructions for reprocessing ancillary equipment to ensure that they are compatible with available procedures.

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.

Mechanical deformation of elastomer medical devices can enable microbial surface colonization

Elastomers such as silicone are common in medical devices (catheters, prosthetic implants, endoscopes), but they remain prone to microbial colonization and biofilm infections. For the first time, our work shows that rates of microbial surface attachment to polydimethylsiloxane (PDMS) silicone can be significantly affected by mechanical deformation. For a section of bent commercial catheter tubing, bacteria (P. aeruginosa) show a strong preference for the 'convex' side compared to the 'concave' side, by a factor of 4.2. Further testing of cast PDMS materials in bending only showed a significant difference for samples that were manually wiped (damaged) beforehand (1.75 × 10⁴ and 6.02 × 10³ cells/mm² on the convex and concave sides, respectively). We demonstrate that surface microcracks in elastomers are opened under tensile stress (convex bending) to become 'activated' as sites for microbial colonization. This work demonstrates that the high elastic limit of elastomers enables these microcracks to reversibly open and close, as 'dynamic defects'. Commercial catheters have relatively high surface roughness inherent to manufacturing, but we show that even manual wiping of newly-cast PDMS is sufficient to generate surface microcracks. We consider the implication for medical devices that feature sustained, surgical, or cyclic deformation, in which localized tensile conditions may expose these surface defects to opportunistic microbes. As a result, our work showcases serious potential problems in the widespread usage and development of elastomers in medical devices.

[A systematic analysis of nosocomial outbreaks of nosocomial infections after gastrointestinal endoscopy]

Esophagogastroduodenoscopy (EGD), endoscopic retrograde cholangiopancreatography (ERCP) and colonoscopy (CLN) come with a potential risk of pathogen transmission. Unfortunately, up to now data on the causes and the distribution of pathogens is rather sparse.We performed a systematic review of the medical literature using the Worldwide Outbreak Database, the PubMed, and Embase. We then checked so-retrieved articles for potential sources of the outbreak, the spectrum of pathogens, the attack rates, mortality and infection control measures.In total 73 outbreaks (EGD: 24, ERCP: 42; CLN: 7) got included. The corresponding attack rates were 3.5%, 7.1% and 12.8% and mortality rates were 6.3%, 12.7% and 10.0% respectively. EGD was highly associated with transmission of enterobacteria including a large proportion of multi-drug resistant strains. ERCP led primarily to transmission of non-fermenting gram-negative rods. The most frequent cause was human failure during reprocessing regardless of the type of endoscope.Staff working in the field of endoscopy should always be aware of the possibility of pathogen transmission in order to detect and terminate those events at the early most time point. Furthermore, proper ongoing education of staff involved in the reprocessing and maintenance of endoscopes is crucial. Single-use devices may be an alternative option and lower the risk of pathogen transmission, but on the downside may also increase costs and waste.

The First Swedish Outbreak with VIM-2-Producing Pseudomonas aeruginosa, Occurring between 2006 and 2007, Was Probably Due to Contaminated Hospital Sinks

Multidrug-resistant Pseudomonas aeruginosa is an increasing clinical problem worldwide. The aim of this study was to describe the first outbreak of a Verona integron-borne metallo-ß-lactamase (VIM)-2-producing P. aeruginosa strain in Sweden and its expansion in the region. A cluster of multidrug-resistant P. aeruginosa appeared at two neighbouring hospitals in 2006. The isolates were characterized by PCR, pulsed-field gel electrophoresis (PFGE), and whole-genome sequencing. Patient charts, laboratory records, and hygiene routines were reviewed, and patients, staff, and the environment were screened. The investigation revealed a clonal outbreak of a VIM-2-producing P. aeruginosa strain belonging to the high-risk clonal complex 111, susceptible only to gentamicin and colistin. No direct contact between patients could be established, but most of them had stayed in certain rooms/wards weeks to months apart. Cultures from two sinks yielded growth of the same strain. The outbreak ended when control measures against the sinks were taken, but new cases occurred in a tertiary care hospital in the region. In conclusion, when facing prolonged outbreaks with this bacterium, sinks and other water sources in the hospital environment should be considered. By implementing proactive control measures to limit the bacterial load in sinks, the waterborne transmission of P. aeruginosa may be reduced.

How effective are the alcohol flush and drying cycles of automated endoscope reprocessors? Stripped endoscope model

BACKGROUND

Effective drying of the internal channels of endoscopes is essential to prevent the growth of water-borne pathogens and to assure adequate sterilization with vaporized hydrogen peroxide or ethylene oxide. The aim of this study was to evaluate the dryness of endoscopes after a routine disinfection process in an automated endoscope reprocessor.

METHODS

Stripped endoscopes (SE) that allow for visual inspection of the inside channels were reprocessed per protocol in a large urban medical center, with a 3-minute or 10-minute air flush following reprocessing. SE was hung and observed for any water within the channels after reprocessing and after a week of ambient storage. Ready-for-use endoscopes were also randomly spot-checked for moisture visually and with moisture detection paper.

RESULTS

All SE were grossly wet after HLD with a 3-minute air flush, despite alcohol flush and drying cycle. The 10-minute air flush was effective at drying the biopsy/suction channel, but not the air/water channels. Hanging had limited effect, being most effective in the biopsy/suction channels. Of the 77 ready-for-use respiratory and gastrointestinal endoscopes assessed, 37 (48.1%) showed evidence of retained moisture.

CONCLUSIONS

Air flush cycles commonly used in the final steps of automated endoscope reprocessing may not adequately dry endoscope channels, particularly the narrower diameter air/water channels. An extended 10-minute air flush appears effective at drying the larger biopsy/suction channel, but has limited effect on the air/water channels.

Green endoscopy: British Society of Gastroenterology (BSG), Joint Accreditation Group (JAG) and Centre for Sustainable Health (CSH) joint consensus on practical measures for environmental sustainability in endoscopy

GI endoscopy is highly resource-intensive with a significant contribution to greenhouse gas (GHG) emissions and waste generation. Sustainable endoscopy in the context of climate change is now the focus of mainstream discussions between endoscopy providers, units and professional societies. In addition to broader global challenges, there are some specific measures relevant to endoscopy units and their practices, which could significantly reduce environmental impact. Awareness of these issues and guidance on practical interventions to mitigate the carbon footprint of GI endoscopy are lacking. In this consensus, we discuss practical measures to reduce the impact of endoscopy on the environment applicable to endoscopy units and practitioners. Adoption of these measures will facilitate and promote new practices and the evolution of a more sustainable specialty.

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

INTRODUCTION

Microbiological surveillance of endoscopes is a safety measure for verifying the quality of reprocessing procedures and identifying contaminated devices, but duodenoscope-related outbreaks are still reported.

AIM

To assess the effectiveness of duodenoscope reprocessing procedures in Italy.

METHODS

Between December 2019 and April 2020, data obtained from microbiological surveillance post-reprocessing in 15 Italian endoscopy units were collected. Sampling was carried out after reprocessing or during storage in a cabinet. In keeping with international guidelines and the Italian position paper, the micro-organisms were classified as high-concern organisms (HCOs) and low-concern organisms (LCOs).

FINDINGS

In total, 144 samples were collected from 51 duodenoscopes. Of these, 36.81% were contaminated: 22.92% were contaminated with HCOs and 13.89% were contaminated with LCOs [2.08% with an LCO load of 11-100 colony-forming units (CFU)/device and 0.69% with an LCO load of >100 CFU/device]. The contamination rate was 27.5% in samples collected after reprocessing, 40% in samples collected during storage in a cabinet that was compliant with EN 16442:2015 (C-I), and 100% in samples collected during storage in a cabinet that was not compliant with EN 16442:2015 (NC-I). The respective HCO rates were 15.00%, 27.27% and 66.67%. Correlation between LCO contamination and storage time was demonstrated (Spearman's rho=0.3701; P=0.0026). The Olympus duodenoscope TJFQ180V demonstrated the lowest rate of contamination (29.82%), although the contamination rate was 100% for duodenoscopes stored in an NC-I cabinet.

CONCLUSION

Microbiological surveillance, along with strict adherence to reprocessing protocols, may help to detect endoscope contamination at an early stage, and reduce the risk of duodenoscope-associated infections.

A prospective, multicenter, clinical study of duodenoscope contamination after reprocessing

OBJECTIVE

Several clinical procedures utilize duodenoscopes, which are processed for reuse after the procedures are completed. However, infection outbreaks due to improper duodenoscope processing occur frequently. To address this, we aimed to assess the contamination rates of duodenoscopes after reprocessing in nonoutbreak settings.

DESIGN AND SETTING

Prospective study in 16 clinical sites in the United States.

METHODS

We sampled and cultured reprocessed duodenoscopes following the FDA/CDC/ASM guideline; "Duodenoscope Surveillance Sampling and Culturing - Reducing the Risks of Infection." High-concern (HC) organisms were those highly associated with disease, including gram-negative rods, Staphylococcus aureus, Staphylococcus lugdunensis, β-hemolytic Streptococcus, Enterococcus spp, and yeasts. We evaluated duodenoscopes with ≥1 CFU of organisms after reprocessing. The reprocessing environments were also sampled and cultured.

RESULTS

We assessed 859 newer-model (NM) duodenoscopes (TJF-Q180V) and 850 older-model (OM) duodenoscopes (TJF-160F/VF); of these, 35 NM samples (4.1%) and 56 OM samples (6.6%) were contaminated with HC organisms. We detected and classified the HC organisms as gastrointestinal (45.4%), human origin (16.7%), environmental (24.1%), waterborne (13.0%), and unidentified (0.9%).

CONCLUSIONS

We detected an overall HC contamination rate of 5.3% in nonoutbreak settings. Although the relationship between endoscopic contamination and the occurrence of infections remains unclear, attempts should continue to be made to further reduce contamination rates. Additional improvements to the manufacturer's instructions for use, human factors during the reprocessing procedure, ongoing training programs, cleanliness of reprocessing environments, and the design of the distal end of the duodenoscope should be considered.

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

BACKGROUND AND AIMS

We investigated whether the use of postmanual cleaning adenosine triphosphate (ATP) tests lowers the number of duodenoscopes and linear echoendoscopes (DLEs) contaminated with gut flora.

METHODS

In this single-center before-and-after study, DLEs were ATP tested after cleaning. During the control period, participants were blinded to ATP results: ATP-positive DLEs were not recleaned. During the intervention period, ATP-positive DLEs were recleaned. DLEs underwent microbiologic sampling after high-level disinfection (HLD) with participants blinded to culture results.

RESULTS

Using 15 endoscopes of 5 different DLE types, we included 909 procedures (52% duodenoscopes, 48% linear echoendoscopes). During the intervention period, the absolute rate of contamination with gut flora was higher (16% vs 21%). The main analysis showed that contamination was less likely to occur in the intervention period (odds ratio, .32; 95% credible interval [CI], .12-.85). A secondary analysis showed that this effect was based on 1 particular duodenoscope type (estimated probability, 39% [95% CI, 18%-64%] vs 9% [95% CI, 2%-21%]), whereas no effect was seen in the other 4 DLE types. In detail, of the 4 duodenoscopes of this type, 2 had lower contamination rates (69% vs 39% and 36% vs 10%). During the control period, both these duodenoscopes had multiple episodes with ongoing contamination with the same microorganism that ended weeks before the start of the intervention period (ie, they were not terminated by ATP testing).

CONCLUSIONS

Postmanual cleaning ATP tests do not reduce post-HLD gut flora contamination rates of DLEs. Hence, postcleaning ATP tests are not suited as a means for quality control of endoscope reprocessing.

Gastrointestinal Endoscopy-Associated Infections: Update on an Emerging Issue

Over 17.7 million gastrointestinal (GI) endoscopic procedures are performed annually, contributing to 68% of all endoscopic procedures in the United States. Usually, endoscopic procedures are low risk, but adverse events may occur, including cardiopulmonary complications, bleeding, perforation, pancreatitis, cholangitis, and infection. Infections after the GI endoscopies most commonly result from the patient's endogenous gut flora. Although many studies have reported infection after GI endoscopic procedures, a true estimate of the incidence rate of post-endoscopy infection is lacking. In addition, the infection profile and causative organisms have evolved over time. In recent times, multi-drug-resistant microorganisms have emerged as a cause of outbreaks of endoscope-associated infections (EAI). In addition, lapses in endoscope reprocessing have been reported, with some but not all outbreaks in recent times. This systematic review summarizes the demographical, clinical, and management data of EAI events reported in the literature. A total of 117 articles were included in the systematic review, with the majority reported from North America and Western Europe. The composite infection rate was calculated to be 0.2% following GI endoscopic procedures, 0.8% following ERCP, 0.123% following non-ERCP upper GI endoscopic procedures, and 0.073% following lower GI endoscopic procedures. Pseudomonas aeruginosa was the most common culprit organism, followed by other Enterobacteriaceae groups of organisms and Gram-positive cocci. We have also elaborated different prevention methods such as antimicrobial prophylaxis, adequate sterilization methods for reprocessing endoscopes, periodic surveillance, and current evidence supporting their utilization. Finally, we discuss disposable endoscopes, which could be an alternative to reprocessing to minimize the chances of EAIs with their effects on the environmental and financial situation.

Risk evaluation of duodenoscope-associated infections in the Netherlands calls for a heightened awareness of device-related infections: a systematic review

BACKGROUND

The risk of exogenous infections from endoscopic procedures is often cited as almost negligible (1 infection in 1.8 million procedures); however, this risk is based on older literature and does not seem to match the number of infectious outbreaks due to contaminated duodenoscopes reported after endoscopic retrograde cholangiopancreatography (ERCP). Using Dutch data, we aimed to estimate the minimum risk of duodenoscope-associated infection (DAI) and colonization (DAC) in patients undergoing ERCP.

METHODS

A systematic literature search identified all DAI outbreaks in the Netherlands reported between 2008 and 2019. Included cases were confirmed by molecular matching of patient and duodenoscope cultures. Risk ratios were calculated based on the total number of ERCPs performed during the study period.

RESULTS

Three outbreaks were reported and published between 2008 and 2018, including 21 confirmed DAI cases and 52 confirmed DAC cases. The estimated number of ERCPs performed during the same period was 181 209-227 006. The calculated minimum estimated DAI risk was approximately 0.01 % and the minimum estimated DAC risk was 0.023 %-0.029 %.

CONCLUSIONS

The estimated risk of DAI in Dutch ERCP practice was at least 180 times higher than previously published risk estimates. The actual risk is likely to be (much) higher due to underreporting of infections caused by multidrug-resistant organisms and sensitive bacteria. Greater awareness by healthcare personnel involved in endoscopy and endoscope cleaning is required, as well as innovative technical solutions to contain and ultimately eliminate DAIs.

[Single-use products in endoscopy-from consumables to single-use scopes]

Clinically relevant infections triggered by the use of flexible endoscopes and respective consumables have become the focus of clinical and scientific interest in the literature. Endoscopy-associated infections can be assigned to one of two groups: (i) endogenous infections are triggered by the spread of the patient's own local flora and (ii) exogenous infections result from transmission of contaminated material or endoscopes. The number of reported infectious complications in flexible endoscopy is low but likely underestimated due to inadequate surveillance strategies and lack of clinical symptoms. To prevent exogenous infections, single-use endoscopes were brought to the market. Single-use bronchoscope have been part of routine clinical care for years, while single-use duodenoscopes have only recently been approved. The increased patient safety and economic costs were clearly evaluated for the single-use bronchoscopes, but this still needs to be studied for single-use duodenoscopes. The use of single-use endoscopes-at first glance-represents an additional financial burden on the healthcare system. However, in addition to the material costs of disposable endoscopes, the costs that are avoided by them (e.g., prolonged hospitalization, intensive care treatment, and follow-up interventions) must also be included in the overall calculation.

Initial application of deep learning to borescope detection of endoscope working channel damage and residue

Background and study aims  Outbreaks of endoscopy-related infections have prompted evaluation for potential contributing factors. We and others have demonstrated the utility of borescope inspection of endoscope working channels to identify occult damage that may impact the adequacy of endoscope reprocessing. The time investment and training necessary for borescope inspection have been cited as barriers preventing implementation. We investigated the utility of artificial intelligence (AI) for streamlining and enhancing the value of borescope inspection of endoscope working channels. Methods  We applied a deep learning AI approach to borescope inspection videos of the working channels of 20 endoscopes in use at our academic institution. We evaluated the sensitivity, accuracy, and reliability of this software for detection of endoscope working channel findings. Results  Overall sensitivity for AI-based detection of borescope inspection findings identified by gold standard endoscopist inspection was 91.4 %. Labels were accurate for 67 % of these working channel findings and accuracy varied by endoscope segment. Read-to-read variability was noted to be minimal, with test-retest correlation value of 0.986. Endoscope type did not predict accuracy of the AI system ( P  = 0.26). Conclusions  Harnessing the power of AI for detection of endoscope working channel damage and residue could enable sterile processing department technicians to feasibly assess endoscopes for working channel damage and perform endoscope reprocessing surveillance. Endoscopes that accumulate an unacceptable level of damage may be flagged for further manual evaluation and consideration for manufacturer evaluation/repair.

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.

Prevalence, Risk Factors, and Molecular Epidemiology of Intestinal Carbapenem-Resistant Pseudomonas aeruginosa

Pseudomonas aeruginosa may become multidrug-resistant (MDR) due to multiple inherited and acquired resistance mechanisms. The human gastrointestinal tract is known as a reservoir of P. aeruginosa and its resistance genes. In this study, we collected 76 intestinal carbapenem-resistant P. aeruginosa (CRPA) strains from clinical inpatients admitted to our hospital from 2014 to 2019, together with their medical data. We aim to analyze the clinical risk factors associated with CRPA infection and its molecular features. We found that the prevalence of CRPA in P. aeruginosa strains was 41.3% (95% confidence interval [CI], 34.1 to 48.8%). We also identified four variables associated with intestinal CRPA positivity, prior antibiotic exposure to aminoglycosides or carbapenems, underlying diabetes mellitus, and extraintestinal P. aeruginosa isolation. bla_KPC-2 is the only detected carbapenemase gene, accounting for 21.1% of CRPA strains. The genetic environment showed that the bla_KPC-2 gene was flanked immediately by ISKpn8 and ISKpn6 and several other mobile elements further upstream or downstream. Four sequence types (STs) were identified, with ST463 as the dominant sequence type. In conclusion, screening for P. aeruginosa colonization upon hospital admission could reduce the risk of P. aeruginosa infection and spread of CRPA in the hospital.

IMPORTANCEPseudomonas aeruginosa may become multidrug-resistant (MDR) due to multiple inherited and acquired resistance mechanisms. The human gastrointestinal tract is known as a reservoir of P. aeruginosa and its resistance genes. Risk factor analysis and molecular epidemiology are critical for preventing their potential dissemination. Here, we identified four risk factors associated with intestinal CRPA—prior antibiotic exposure to aminoglycosides or carbapenems, underlying diabetes mellitus, and extraintestinal P. aeruginosa isolation. Further, we found similar genetic environments with several mobile elements surrounding the bla_KPC gene, a carbapenemase gene only detected in intestinal CRPA strains in this study. These findings are of significant public health importance, as the information will facilitate the control of the emergence and spread of CRPA.

Both microbiological surveillance and audit of procedures improve reprocessing of flexible bronchoscopes and patient safety

BACKGROUND

Microbiological surveillance of bronchoscopes and automatic endoscope reprocessors (AERs)/washer disinfectors as a quality control measure is controversial. Experts also are divided on the infection risks associated with bronchoscopic procedures.

OBJECTIVE

We evaluated the impact of routine microbiological surveillance and audits of cleaning/disinfection practices on contamination rates of reprocessed bronchoscopes.

DESIGN

Audits were conducted of reprocessing procedures and microbiological surveillance on all flexible bronchoscopes used from January 2007 to June 2020 at a teaching hospital in France. Contamination rates per year were calculated and analyzed using a Poisson regression model. The risk factors for microbiological contamination were analyzed using a multivariable logistical regression model.

RESULTS

In total, 478 microbiological tests were conducted on 91 different bronchoscopes and 57 on AERs. The rate of bronchoscope contamination significantly decreased between 2007 and 2020, varying from 30.2 to 0% (P < .0001). Multivariate analysis confirmed that retesting after a previous contaminated test was significantly associated with higher risk of bronchoscope contamination (OR, 2.58; P = .015). This finding was explained by the persistence of microorganisms in bronchoscopes despite repeated disinfections. However, the risk of persistent contamination was not associated with the age of the bronchoscope.

CONCLUSIONS

Our results confirm that bronchoscopes can remain contaminated despite repeated reprocessing. Routine microbial testing of bronchoscopes for quality assurance and audit of decontamination and disinfection procedures can improve the reprocessing of bronchoscopes and minimize the rate of persistent contamination.

Multisocieties position paper: Microbiological surveillance on flexible endoscopes

Transmission with endoscopes, particularly duodenoscope, of potential lethal infections prompted different scientific societies to deliver recommendations aimed reducing this risk. Some International societies extended recommendations on microbial surveillance to all the endoscopes and devices used in the reprocessing procedure. Considering the relevance of the topic, 8 Italian scientific societies of physicians, nurses and technical operators prepared a concerted document taking into account Institutional advisories and facilities in Italy. The rules for a correct microbial surveillance on endoscopes were detailed in term of what, how and when to perform the procedure, also suggesting behaviors in case of contamination.

Economic burden of enhanced practices of duodenoscopes reprocessing and surveillance: balancing risk and cost containment

Background and study aims  Recent outbreaks attributed to contaminated duodenoscopes have led to the development of enhanced surveillance and reprocessing techniques (enhanced-SRT) aimed at minimizing cross-contamination. Common enhanced-SRT include double high-level disinfection (HLD), ethylene oxide (EtO) gas sterilization, and culture-based monitoring of reprocessed scopes. Adoption of these methods adds to the operational costs and we aimed to assess its economic impact to an institution. Methods  We compared the estimated costs of three enhanced-SRT versus single-HLD using data from two institutions. We examined the cost of capital measured as scope inventory and frequency of scope use per unit time, the constituent reprocessing costs required on a per-cycle basis, and labor & staffing needs. The economic impact attributable to enhanced-SRT was defined as the difference between the total cost of enhanced-SRT and single HLD. Results  Compared to single HLD, adoption of double HLD increased the costs approximately by 47 % ($80 vs $118). Similarly, culture and quarantine and EtO sterilization increased costs by 160 % and 270 %, respectively ($80 vs $208 and $296). Enhanced-SRT introduced significant scope downtime due to prolonged techniques, necessitating a 3.4-fold increase in the number of scopes needed to maintain procedural volume. The additional annual budget required to implement enhanced-SRT approached $406,000 per year in high-volume centers. Conclusions  While enhanced-SRT may reduce patient risk of exposure to contaminated duodenoscopes, it significantly increases the cost of performing ERCP. Future innovation should focus on approaches that can ensure patient safety while maintaining the ability to perform ERCP in a cost-effective manner.

Investigation of possible transmission of a susceptible microorganism through a contaminated duodenoscope; a case report

BACKGROUND

Despite compliance to extensive reprocessing protocols, duodenoscopes have been linked to outbreaks of susceptible and multi-drug resistant organisms (MDRO) due to persistent duodenoscope contamination. Duodenoscope-associated infections (DAIs) based on transmission of susceptible microorganisms are likely to be underreported due to detection bias.

CASE PRESENTATION

We describe the retrospective detection of a DAI case caused by a susceptible microorganism which at the time of clinical infection was not recognized as such. During 2017 and 2018, duodenoscopes were cultured on a daily basis due to research activities. While analyzing this data, it was found that a duodenoscope had been contaminated with Enterobacter cloacae complex over a period of 3 months. We checked whether patients treated with this duodenoscope had developed infections and found one patient with an E. cloacae cholangitis 3 months after the ERCP (Endoscopic retrograde cholangiopancreaticography) procedure. The isolates on the duodenoscope and in the patients' blood culture were indistinguishable by amplified fragment length polymorphism (AFLP). By classical multi-locus sequence typing (MLST), both strains were of the same (but novel) sequence type. Application of whole genome MLST showed 93 (out of 3757) allelic differences.

CONCLUSION

This case report describes a plausible link between a contaminated duodenoscope and a patient infection with E. cloacae. Transmission of susceptible E. cloacae was highly suspected from AFLP and MLST results; by WGS, 93 allelic differences were found which proves closely related strains. This report shows that DAIs by susceptible microorganisms can be easily missed and therefore its true prevalence remains underscored.

Endoscopic retrograde cholangiopancreatography: Current practice and future research

Endoscopic retrograde cholangiopancreatography (ERCP) has evolved from a primarily diagnostic to therapeutic procedure in hepatobiliary and pancreatic disease. Most commonly, ERCPs are performed for choledocholithiasis with or without cholangitis, but improvements in technology and technique have allowed for management of pancreatic duct stones, benign and malignant strictures, and bile and pancreatic leaks. As an example of necessity driving innovation, the new disposable duodenoscopes have been introduced into practice. With the advantage of eliminating transmissible infections, they represent a paradigm shift in quality improvement within ERCP. With procedures becoming more complicated, the necessity for anesthesia involvement and safety of propofol use and general anesthesia has become better defined. The improvements in endoscopic ultrasound (EUS) have allowed for direct bile duct access and EUS facilitated bile duct access for ERCP. In patients with surgically altered anatomy, selective cannulation can be performed with overtube-assisted enteroscopy, laparoscopic surgery assistance, or the EUS-directed transgastric ERCP. Cholangioscopy and pancreatoscopy use has become ubiquitous with defined indications for large bile duct stones, indeterminate strictures, and hepatobiliary and pancreatic neoplasia. This review summarizes the recent advances in infection prevention, quality improvement, pancreaticobiliary access, and management of hepatobiliary and pancreatic diseases. Where appropriate, future research directions are included in each section.

Single Use (disposable) Duodenoscope: Recent Development and Future

Unlike simple forward-viewing endoscopes such as gastroscope or colonoscope, duodenoscope houses much more complex design to fulfil its function. This design differences leave duodenoscopes more prone to contamination from inadequate disinfection process and potential dissemination of pathogens. Recent reports on dissemination of infection through the duodenoscope mandated an overhaul of duodenoscope utilization including development of a disposable duodenoscope. This article reviews the current state of disposable duodenoscope development, including reported early efficacy as well as its future direction and utilization.

Equivalent performance of single-use and reusable duodenoscopes in a randomised trial

OBJECTIVE

Single-use duodenoscopes have been recently developed to eliminate risk of infection transmission from contaminated reusable duodenoscopes. We compared performances of single-use and reusable duodenoscopes in patients undergoing endoscopic retrograde cholangiopancreatography (ERCP).

DESIGN

Patients with native papilla requiring ERCP were randomised to single-use or reusable duodenoscope. Primary outcome was comparing number of attempts to achieve successful cannulation of desired duct. Secondary outcomes were technical performance that measured duodenoscope manoeuvrability, mechanical-imaging characteristics and ability to perform therapeutic interventions, need for advanced cannulation techniques or cross-over to alternate duodenoscope group to achieve ductal access and adverse events.

RESULTS

98 patients were treated using single-use (n=48) or reusable (n=50) duodenoscopes with >80% graded as low-complexity procedures. While median number of attempts to achieve successful cannulation was significantly lower for single-use cohort (2 vs 5, p=0.013), ease of passage into stomach (p=0.047), image quality (p<0.001), image stability (p<0.001) and air-water button functionality (p<0.001) were significantly worse. There was no significant difference in rate of cannulation, adverse events including mortality (one patient in each group), need to cross-over or need for advanced cannulation techniques to achieve ductal access, between cohorts. On multivariate logistic regression analysis, only duodenoscope type (single-use) was associated with less than six attempts to achieve selective cannulation (p=0.012), when adjusted for patient demographics, procedural complexity and type of intervention.

CONCLUSION

Given the overall safety profile and similar technical performance, single-use duodenoscopes represent an alternative to reusable duodenoscopes for performing low-complexity ERCP procedures in experienced hands.

TRIAL REGISTRATION NUMBER

Clinicaltrials.gov number: NCT04143698.

Nosocomial transmission of a blaVIM-2 carbapenemase integron between isolates of two different Pseudomonas species

We report the first documented in-hospital patient-to-patient-transmission of a blaVIM-2 integron between isolates of Pseudomonas alcaligenes and P. aeruginosa. Molecular typing looking only for difference within species may fail to detect nosocomial transmission of resistance genes.

Duodenoscope-associated infection prevention: A call for evidence-based decision making

Background  Recent outbreaks of duodenoscope-associated multidrug-resistant organisms (MDROs) have brought attention to the infection risk from procedures performed with duodenoscopes. Prior to these MDRO outbreaks, procedures with duodenoscopes were considered safe and low risk for exogenous infection transmission, provided they were performed in strict accordance with manufacturer instructions for use and multisociety reprocessing guidelines. The attention and efforts of the scientific community, regulatory agencies, and the device industry have deepened our understanding of factors responsible for suboptimal outcomes. These include instrument design, reprocessing practices, and surveillance strategies for detecting patient and instrument colonization. Various investigations have made it clear that current reprocessing methods fail to consistently deliver a pathogen-free instrument. The magnitude of infection transmission has been underreported due to several factors. These include the types of organisms responsible for infection, clinical signs presenting in sites distant from ERCP inoculation, and long latency from the time of acquisition to infection. Healthcare providers remain hampered by the ill-defined infectious risk innate to the current instrument design, contradictory information and guidance, and limited evidence-based interventions or reprocessing modifications that reduce risk. Therefore, the objectives of this narrative review included identifying outbreaks described in the peer-reviewed literature and comparing the findings with infections reported elsewhere. Search strategies included accessing peer-reviewed articles, governmental databases, abstracts for scientific conferences, and media reports describing outbreaks. This review summarizes current knowledge, highlights gaps in traditional sources of evidence, and explores opportunities to improve our understanding of actual risk and evidence-based approaches to mitigate risk.

Novel Algorithms for Reprocessing, Drying and Storing Endoscopes

After outbreaks of duodenoscope-transmitted infection with multidrug-resistant organisms, it has become clear that institutions must optimize their endoscope reprocessing programs. Standard endoscope reprocessing practices may not represent the ideal approach for preventing transmission of infection related to endoscopy. We discuss multiple approaches to enhance and optimize reprocessing, drying, and storage of standard duodenoscopes. The optimal enhanced duodenoscope reprocessing modality remains to be determined. Acknowledging the challenges and limitations in effectively reprocessing duodenoscopes, the FDA issued a safety communiqué recommending transitioning to either single use disposable duodenoscopes or duodenoscopes with innovative designs that allow more effective reprocessing.

Introduction to Transmission of Infection: Potential Agents Transmitted by Endoscopy

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

Methods for Endoscope Reprocessing

Over the past 2 decades, in hospital centers worldwide, there have been numerous outbreaks of multidrug-resistant organisms that have since been attributed to endoscopic transmission of the infections between patients, primarily from duodenoscopes. These outbreaks have focused the attention of endoscope manufacturers, professional societies, and regulatory agencies on improving the reprocessing of these devices. The key steps in this process are point-of-use precleaning, leak testing, manual cleaning, high-level disinfection, and finally drying and storage. The promise of these initial efforts suggest that the aim of minimizing and ultimately eliminating events of endoscope-/duodenoscope-associated transmission of infectious organisms between patients can be achieved.

Remote video auditing in the endoscopy unit for evaluation of duodenoscope reprocessing in a tertiary care center

BACKGROUND : A significant proportion of duodenoscope-transmitted infections have resulted from errors related to reprocessing. Remote video auditing (RVA) is a tool that can monitor reprocessing compliance but it has not been previously evaluated in a tertiary care setting. The aims of this study were to evaluate: 1) RVA feasibility in a tertiary care setting (defined as the ability to audit every step of duodenoscope reprocessing without delaying the next procedure due to unavailability of duodenoscopes); and 2) the use of RVA as a compliance monitoring tool. METHODS : This was a prospective study at a tertiary care center. A video camera with offsite monitoring was installed in March 2018. Auditors delivered a compliance score after each procedure. The duodenoscope was not used until it passed the audit. Feasibility and compliance data were collected from April 2018 to August 2019 after a 1-month run-in phase. Both per-step compliance and overall 100 % compliance rates were measured. RESULTS : Of 743 duodenoscope reprocessing procedures, 32 666 individual steps were audited and 99.9 % of the steps were fully viewable. The mean time per audit was 38.3 minutes, the mean duodenoscope turnover time was 76.1 minutes, and there were no delays to the next procedure due to unavailability of duodenoscopes. The per-step compliance rate was 99.5 % but the overall 100 % compliance rate was 90.3 %. CONCLUSIONS : The use of RVA in duodenoscope reprocessing was feasible and promoted sustained high-level compliance in a tertiary care center.

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.

Bilio-pancreatic endoscopy during COVID-19 pandemic

On 31 December 2019, the WHO China Country Office was informed of cases of pneumonia of unknown etiology detected in Wuhan (Hubei Province of China). In January 2020, a new coronavirus named SARS-CoV2 was isolated and, since that time, SARS-CoV2 related disease (COVID-19) rapidly spread all over the world becoming pandemic in March 2020. The COVID-19 outbreak dramatically affected the public-health and the health-care facilities organization. Bilio-pancreatic endoscopy is considered a high-risk procedure for cross-contamination and, even though it is not directly involved in COVID-19 diagnosis and management, its reorganization is crucial to guarantee high standards of care minimizing the risk of SARS-CoV2 transmission among patients and health-care providers. Bilio-pancreatic endoscopic procedures often require a short physical distance between the endoscopist and the patient for a long period of time, a frequent exchange of devices, the involvement of a large number of personnel, the use of complex endoscopes difficult to reprocess. On this basis, endoscopic units should take precautions with adjusted management of bilio-pancreatic endoscopy. The aim of this article is to discuss the approach to bilio-pancreatic endoscopy in the COVID-19 era with focus on diagnostic algorithms, indications, management of the endoscopic room, proper use of Personal Protective Equipment and correct reprocessing of instrumentation.

A Manufacturer and User Facility Device Experience Analysis of Upper Aerodigestive Endoscopy Contamination: Is Flexible Laryngoscopy Different?

OBJECTIVES/HYPOTHESIS

Several recent studies have observed a high incidence of duodenoscope microbial contamination and an association of contamination with healthcare-acquired infections. This study sought to quantify nasopharyngoscope microbial contamination relative to that of other endoscope categories and characterize the manufacturers, outcomes, and microbial profiles associated with these cases.

STUDY DESIGN

Retrospective, cross-sectional study.

METHODS

A total of 3,865 adverse events were collected from 2013 to 2019 using the US Food and Drug Administration Manufacturer and User Facility Device Experience database. The fraction of total device failures associated with contamination was quantified for nasopharyngoscopes, bronchoscopes, duodenoscopes, and gastroscopes. Odds ratios of nasopharyngoscope contamination compared to that of bronchoscopes, duodenoscopes, or gastroscopes were calculated, and significance was assessed by χ² analysis. The Kruskal-Wallis test was used for nonparametric testing of significance.

RESULTS

Nasopharyngoscope device failures were reported at an incidence of 0.646 per month; 34.1% involved contamination, comparable to the frequency observed for bronchoscopes (23.4%, P = .118), duodenoscopes (29.2%, P = .493), and gastroscopes (45.3%, P = .178). The frequency of device contamination was observed to be significantly higher for a particular endoscope manufacturer regardless of endoscope category (Kruskal-Wallis P = .021). In instances of contamination, nasopharyngoscopes were significantly less associated with patient harm or death than bronchoscope (odds ratio [OR] = 10.2) and duodenoscope (OR = 4.81) cases.

CONCLUSIONS

Although the rates of contamination were comparable across all endoscope categories, nasopharyngoscope contamination was less commonly associated with patient harm or death. In an era of rising healthcare costs, determining adequate disinfection standards for nasopharyngoscopes and their impact on patient safety is crucial.

LEVEL OF EVIDENCE

NA Laryngoscope, 131:598-605, 2021.

Contribution of usage to endoscope working channel damage and bacterial contamination

BACKGROUND

Biofilm formation has been shown to be associated with damaged areas of endoscope channels. It was hypothesized that the passage of instruments and brushes through endoscope channels during procedures and cleaning contributes to channel damage, bacterial attachment and biofilm formation.

AIM

To compare surface roughness and bacterial attachment in used and new endoscope channels in vivo and in vitro.

METHODS

Surface roughness of 10 clinically used (retired) and seven new colonoscope biopsy channels was analysed by a surface profiler. For the in-vitro study, a flexible endoscope biopsy forceps was passed repeatedly through a curved 3.0-mm-diameter Teflon tube 100, 200 and 500 times. Atomic force microscopy was used to determine the degree of inner surface damage. The number of Escherichia coli or Enterococcus faecium attached to the inner surface of the new Teflon tube and the tube with 500 forceps passes in 1 h at 37^oC was determined by culture.

RESULTS

The average surface roughness of the used biopsy channels was found to be 1.5 times greater than that of the new biopsy channels (P=0.03). Surface roughness of Teflon tubes with 100, 200 and 500 forceps passes was 1.05-, 1.12- and 3.2-fold (P=0.025) greater than the roughness of the new Teflon tubes, respectively. The number of E. coli and E. faecium attached to Teflon tubes with 500 forceps passes was 2.9-fold (P=0.021) and 4.3-fold (P=0.004) higher compared with the number of E. coli and E. faecium attached to the new Teflon tubes, respectively.

CONCLUSION

An association was found between endoscope usage with damage to the biopsy channel and increased bacterial attachment.

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

OVERVIEW

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

MATERIALS & METHODS

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

RESULTS

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

CONCLUSIONS

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

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

Objective

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

Method

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

Results

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

Conclusion

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

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.