ESGE-ESGENA guideline for quality assurance in reprocessing: microbiological surveillance testing in endoscopy

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.

NCCP-ICS joint consensus-based clinical practice guidelines on medical thoracoscopy

ABSTRACT

Medical Thoracoscopy (MT) is commonly performed by respiratory physicians for diagnostic as well as therapeutic purposes. The aim of the study was to provide evidence-based information regarding all aspects of MT, both as a diagnostic tool and therapeutic aid for pulmonologists across India. The consensus-based guidelines were formulated based on a multistep process using a set of 31 questions. A systematic search of published randomized controlled clinical trials, open labelled studies, case reports and guidelines from electronic databases, like PubMed, EmBase and Cochrane, was performed. The modified grade system was used (1, 2, 3 or usual practice point) to classify the quality of available evidence. Then, a multitude of factors were taken into account, such as volume of evidence, applicability and practicality for implementation to the target population and then strength of recommendation was finalized. MT helps to improve diagnosis and patient management, with reduced risk of post procedure complications. Trainees should perform at least 20 medical thoracoscopy procedures. The diagnostic yield of both rigid and semirigid techniques is comparable. Sterile-graded talc is the ideal agent for chemical pleurodesis. The consensus statement will help pulmonologists to adopt best evidence-based practices during MT for diagnostic and therapeutic purposes.

Is ultraviolet light disinfection fit to be the future standard for the disinfection of flexible endoscopes without a working channel?

OBJECTIVE

To investigate colony-forming unit (CFU) reduction on contaminated flexible endoscopes (FEs) without a working channel after UV-C light disinfection, compared to the current disinfection method with the endoscope washer disinfector (EWD).

DESIGN, SETTING AND PARTICIPANTS

After pharyngolaryngoscopy, a manual pre-cleaning with tap water was performed. A culture was then collected by rolling the distal 8-10 cm of the FE over an Agar plate. The FE was disinfected using the D60 (60-s disinfection process with UV-C light) or the EWD (gold standard reprocessing process with water and chemicals). Another culture was then taken. After incubation, a CFU count was performed.

RESULTS

A total of 200 FEs without a working channel were divided equally between the two disinfection groups. After clinical use and manual pre-cleaning, 84 of the 100 (84.0%) (UV-C light group) and 79 of the 100 (79.0%) (EWD) FEs were contaminated with at least 1 CFU. FEs that showed no contamination after use were excluded from further analysis. After disinfection with UV-C light, 72 (85.7%) FEs showed no contamination (i.e., 0 CFUs) versus 66 (83.5%) FEs after reprocessing with the EWD.

CONCLUSION

There is no difference in CFUs reduction on contaminated FEs without a working channel between UV-C light disinfection and the current gold standard, the EWD.

Assessment of endoscope reprocessing at World Gastroenterology Organisation training centers using adenosine triphosphate testing

Background and study aims Adequacy of endoscope disinfection in resource-limited settings is unknown. Adenosine triphosphate (ATP) testing is useful for evaluation of endoscope reprocessing, and ATP <200 relative light units (RLUs) after manual endoscope cleaning has been associated with adequacy of endoscope disinfection. Methods Consecutive endoscopes undergoing reprocessing at five World Gastroenterology Organisation (WGO) training centers underwent ATP testing before and after an on-site educational intervention designed to optimize reprocessing practices. Results A total of 343 reprocessing cycles of 65 endoscopes were studied. Mean endoscope age was 5.3 years (range 1-13 years). Educational interventions, based on direct observation of endoscope reprocessing practices at each site, included refinements in pre-cleaning, manual cleaning, high-level disinfection, and endoscope drying and storage. The percentage of reprocessing cycles with post-manual cleaning ATP ≧200 decreased from 21.4% prior to educational intervention to 14.8% post-intervention ( P =0.11). In multivariable logistic modelling, gastroscopes were significantly less likely (odds ratio [OR] 0.04, 95% confidence interval [CI] 0.01-0.19; P <0.001) than colonoscopes to achieve post-manual cleaning ATP < 200. No other factor (educational intervention, study site, endoscope age) was significantly associated with improved outcomes. Endoscope ID was not significantly associated with ATP values, and sites that performed manual versus automated HLD did not have significantly different likelihood of post-manual cleaning ATP <200 (OR 1.18, 95% CI 0.56-2.50; P =0.67). Conclusions In resource-limited settings, approximately 20% of endoscope reprocessing cycles may result in inadequate disinfection. This was not significantly improved by a comprehensive educational intervention. Alternative approaches to endoscope reprocessing are needed.

Endoscope reprocessing: Retrospective analysis of 90,311 samples

Background and study aims The contamination level of ready-to-use endoscopes published in the literature varies from 0.4 % to 49.0 %. Unfortunately, the comparison and the interpretation of these results are quite impossible, given the limited number of samples and sites included and the differences observed between sampling, culturing methods, and interpretation criteria. Methods The objective of this retrospective study was to analyze the results of 90,311 endoscope samples collected between 2004 and 2021 in 490 private or public hospitals in France. Results Through the full test period, the mean ratio of endoscopes at the action level was 12.6 % (19.5 % including alert level). Of the endoscopy units, 23.0 % had a ratio of compliant endoscopes ≤ 70.0 %. The overall microbial quality of gastroscopes, duodenoscopes, and colonoscopes is improving year by year, whereas an opposite trend is observed for ultrasound endoscopes and bronchoscopes. In 2021, following French guidelines, 13.0 % of the endoscopes should have been quarantined and 8.1 % were at the alert level, meaning that the contamination level of 21.1 % of the endoscopes exceeded what was defined as a maximum acceptable value. Conclusions This study demonstrates that additional efforts, including implementation of microbial surveillance strategies using a standardized sampling method and periodic observational audits, must be made to improve the overall microbiological quality of endoscopes and reduce the risk associated with their use.

Cross-contamination rate of reusable flexible bronchoscopes: A systematic literature review and meta-analysis

Background

Bronchoscopy is generally a safe and efficient procedure. However, the risk of cross-contamination with reusable flexible bronchoscopes (RFB) has been detected in several outbreaks worldwide.

Aim

To estimate the average cross-contamination rate of patient-ready RFBs based on available published data.

Methods

We performed a systematic literature review in PubMed and Embase to investigate the cross-contamination rate of RFB. Included studies identified indicator organisms or colony forming units (CFU) levels, and total number of samples >10. The Contamination threshold was defined according to the European Society of Gastrointestinal Endoscopy and European Society of Gastrointestinal Endoscopy Nurse and Associates (ESGE-ESGENA) guidelines. To calculate the total contamination rate, a random effects model was applied. Heterogeneity was analysed via a Q-test and illustrated in a forest plot. Publication bias was analysed via the Egger’s regression test and illustrated in a funnel plot.

Results

Eight studies fulfilled our inclusion criteria. The random effects model included 2169 samples and 149 events (positive tests). The total RFB cross-contamination rate was 8.69% ± 1.86 (standard division [SD]) (95% confidence interval [CI]: 5.06–12.33%). The result showed significant heterogeneity of 90% and publication bias.

Discussion

Significant heterogeneity and publication bias is likely associated with varying methodology and aversion towards publishing negative findings, respectively. Based on the cross-contamination rate an infection control paradigm shift is needed to ensure patient safety. We recommend to follow the Spaulding classification and classify RFBs as critical items. Accordingly, infection control measures such as obligatory surveillance, and implementing single-use alternatives must be considered where feasible.

Higher yield in duodenoscope cultures collected with addition of neutralizing agent

AIM

Microbiological cultures are the gold standard in the monitoring of duodenoscope reprocessing. However, many different sampling and culturing techniques are used, making it difficult to compare results. The latest Centers for Disease Control and Prevention protocol advises the use of a neutralizer to deactivate any remaining disinfectants in the samples. This study compared culturing results of duodenoscope samples collected with and without addition of a neutralizer.

METHODS

Six duodenoscopes were soiled with gut bacteria in a non-clinical experimental setting and reprocessed afterwards. Samples of the tip and working channel were collected immediately after decontamination or after drying. Dey-Engley (DE) broth was added as a neutralizer to the samples of four duodenoscopes; samples for the other two duodenoscopes were collected without the addition of DE broth.

RESULTS

Post-decontamination cultures were significantly more likely to be positive for growth of the applied micro-organisms in the group of samples with DE broth (88.1% vs 20.2%; P<0.0001). Post-drying samples were significantly more likely to be positive in the group of samples without DE broth (75.7% vs 33.4%; P<0.001).

CONCLUSION

The addition of DE broth to samples collected from wet duodenoscopes increases the yield of those cultures. Remaining disinfectants in wet duodenoscopes can lead to false-negative results. This can be overcome by adding a neutralizer, such as DE broth, to the samples. The higher yield after drying in the group without neutralizer could be due to biofilm formation in these two duodenoscopes, but this was not investigated. Standardization of the sampling method can help to compare both clinical and study results regarding duodenoscope contamination.

Bacterial contamination and organic residue after reprocessing in duodenoscopes with disposable distal caps compared with duodenoscopes with fixed distal caps: a randomized trial

BACKGROUND AND AIMS

Newly designed duodenoscopes with disposable distal caps have been developed for better cleaning and preprocessing to reduce the risk of bacterial contamination (BC). We compared BC and organic residue of duodenoscopes with disposable distal caps and duodenoscopes with fixed distal caps after manual cleaning and high-level disinfection (HLD).

METHODS

Four hundred duodenoscopes were randomized into group A (fixed distal caps, n = 200) and group B (disposable distal caps, n = 200). After manual cleaning, samples from the elevator were submitted for culture. An adenosine triphosphate (ATP) test was performed for organic residue evaluation. Based on our previous data, ATP < 40 relative light units (RLUs) had 100% sensitivity with 100% negative predictive value to confirm no BC after reprocessing.

RESULTS

After manual cleaning, group A had a higher BC rate (14% vs 7%, P = .02), a higher proportion of duodenoscopes with ATP ≥ 40 RLUs (73.5% vs 57%, P = .001), and a higher mean of ATP level (226.6 vs 82.0 RLUs, P < .001) compared with group B. After HLD, the proportion of potential BC (ATP ≥ 40 RLUs) in group A was 2.7 times higher than group B (4% vs 1.5%, P = .13). Mean ATP level after HLD in the 2 groups was significantly lower than before the HLD procedure (group A, 24.2 vs 226.6 RLUs [P < .001]; group B, 20.4 vs 82.0 RLUs [P < .001], respectively).

CONCLUSIONS

After manual cleaning, duodenoscopes with disposable distal caps had significantly lower BC and organic residue than duodenoscopes with fixed distal caps. Only a few duodenoscopes from each group did not pass the ATP threshold after HLD.

High Prevalence Rate of Microbial Contamination in Patient-Ready Gastrointestinal Endoscopes in Tehran, Iran: an Alarming Sign for the Occurrence of Severe Outbreaks

An alarmingly increasing number of outbreaks caused by contaminated gastrointestinal (GI) endoscopes are being reported as a particularly concerning issue. This study is the first large-scale multicenter survey to evaluate the contamination of GI endoscopes in Tehran, Iran. This multicenter study was conducted among 15 tertiary referral and specialized gastrointestinal settings. Reprocessed GI endoscopes were sampled by the sequence of the flush-brush-flush method. Bacterial and viral contamination, as well as antimicrobial resistance, were explored by culture and molecular assays. A total of 133 reprocessed and ready-to-use GI endoscopes were investigated. In phase I and phase II, 47% and 32%, respectively, of the GI endoscopes were determined to be contaminated. GI flora was the most prevalent contaminant isolated from GI endoscopes, in which the most predominant bacteria were Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae, in both phase I and II evaluations. The majority of the isolated bacteria in the current study were considered multidrug-resistant organisms (MDROs). More importantly, we recovered carbapenem-resistant nonfermentative Gram-negative bacilli (CRNFGNB), carbapenem-resistant Enterobacterales (CRE), extended-spectrum β-lactamase (ESBL)-producing Enterobacterales (ESBL-E), multidrug-resistant Clostridioides difficile, vancomycin-resistant Enterococcus (VRE), and drug-resistant Candida spp. Disconcertingly, our molecular assays revealed contamination of some reprocessed GI endoscopes with hepatitis B virus (HBV), hepatitis C virus (HCV), and even HIV. This multicenter study indicates a higher-than-expected contamination rate among reprocessed and ready-for-patient-use GI endoscopes, which suggests a higher-than-expected endoscopy-associated infection (EAI) risk, and potentially, morbidity and mortality rate, associated with endoscopy procedures in Tehran, Iran. IMPORTANCE In the light of severe outbreaks caused by multidrug-resistant microorganisms due to contaminated GI endoscopes, understanding to what extent GI endoscopes are inadequately reprocessed is crucial. Several studies assessed contamination of GI endoscopes with various outcomes across the world; however, the prevalence and risk factors of contaminated GI endoscopes and potential subsequent nosocomial spread are still unknown in Iran. The present study is the first large-scale multicenter survey to evaluate the microbial contamination of repossessed and ready-to-use GI endoscopes in Tehran, Iran. Our study showed a higher-than-expected contamination rate among reprocessed GI endoscopes, which suggests potential seeding of deadly but preventable outbreaks associated with endoscopy procedures in Iran. These results suggest that the current reprocessing and process control guidelines do not suffice in Iran. The current study is of particular importance and could provide insights into unrecognized and unidentified endoscopy-associated outbreaks in Iran.

Disinfection of otorhinolaryngological endoscopes with electrolyzed acid water: A cross-sectional and multicenter study

Glutaraldehyde, a germicide for reprocessing endoscopes that is important for hygiene in the clinic, might be hazardous to humans. Electrolyzed acid water (EAW) has a broad anti-microbial spectrum and safety profile and might be a glutaraldehyde alternative. We sought to assess EAW disinfection of flexible endoscopes in clinical otorhinolaryngological settings and its in vitro inactivation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and bacteria commonly isolated in otorhinolaryngology. Ninety endoscopes were tested for bacterial contamination before and after endoscope disinfection with EAW. The species and strains of bacteria were studied. The in vitro inactivation of bacteria and SARS-CoV-2 by EAW was investigated to determine the efficacy of endoscope disinfection. More than 20 colony-forming units of bacteria at one or more sampling sites were detected in 75/90 microbiological cultures of samples from clinically used endoscopes (83.3%). The most common genus detected was Staphylococcus followed by Cutibacterium and Corynebacterium at all sites including the ears, noses, and throats. In the in vitro study, more than 107 CFU/mL of all bacterial species examined were reduced to below the detection limit (<10 CFU/mL) within 30 s after contact with EAW. When SARS-CoV-2 was treated with a 99-fold volume of EAW, the initial viral titer (> 105 PFU) was decreased to less than 5 PFU. Effective inactivation of SARS-CoV-2 was also observed with a 19:1 ratio of EAW to the virus. EAW effectively reprocessed flexible endoscopes contributing to infection control in medical institutions in the era of the coronavirus disease 2019 pandemic.

Good Practices on Endoscope Reprocessing in Italy: Findings of a Nationwide Survey

Background: Correct reprocessing and microbiological surveillance on endoscopes are fundamental for preventing the transmission of multi-drug resistant strains and device-related infections. Methods: A questionnaire with three domains was created: (1) centre characteristics; (2) endoscope reprocessing procedures; and (3) application of microbiological surveillance. Nurses working in endoscopic units across Italy were invited to anonymously fill out the questionnaire on the SurveyMonkey platform between November 2021 and February 2022. Results: A total of 82 out of 132 endoscopic centres participated in the survey, with at least one centre from each Italian region. Data found different concerns regarding the current practice of both reprocessing and microbiological surveillance. According to respondents, the training on reprocessing was performed through theoretical training and only in 10% of centres; the microbiological surveillance was regularly performed in 59% of centres; and sampled endoscopes were not excluded for use in 31% of centres performing the surveillance until the outcome was pending, and when positive, 72% maintained them in quarantine until a successive negative result. Conclusions: Reprocessing and microbiological surveillance currently present several criticisms along the endoscopic centres in Italy. Our survey highlights the need for the correct application of the national recommendations in each endoscopic centre to prevent the potential transmission of endoscope-related infections.

No relation between adenosine triphosphate after manual cleaning and presence of microorganisms on endoscopes after automated high-level disinfection

Background and study aims  Adenosine triphosphate (ATP) tests are increasingly used to detect biological material; however, their reliability to detect bacterial contamination in endoscopes is not proven. We investigated the predictive value of ATP tests after manual cleaning for presence or absence of microorganisms as shown by culture after automated high-level disinfection (HLD) in duodenoscopes and linear echoendoscopes (DLEs). Patients and methods  After manual cleaning, ATP tests were performed on swab samples taken from the detachable cap and forceps elevator, and on flush samples of the DLE working channels. These results were compared to the growth of any microorganisms in cultures acquired after automated HLD. ATP tests with > 200 relative light units (RLU) were considered positive. Receiver operator characteristic (ROC) curves were used to compare the RLU levels with microbial presence in cultures. Results  In total, 903 procedures were performed involving 26 distinct DLEs. Depending on sample site, 20.8 % (cap) to 63.8 % (channel brush) of the ATP negative samples were accompanied by positive post-HLD cultures. 54.4 % of the cap samples with a positive culture (growth of any kind of microorganism) and 91.8 % of the channel samples with a positive culture had a negative ATP test after manual cleaning. ROC curves per sample site, DLE type and microorganism type all had area under the curves below 0.6. Conclusions  In our study, ATP tests performed after manual cleaning could not predict presence or absence of microorganisms after automated HLD as shown by culture. More than half of the positive cultures were preceded by a negative ATP test.

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

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

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

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

A narrative review on current duodenoscope reprocessing techniques and novel developments

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

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

BACKGROUND

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

METHODS

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

RESULT

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

CONCLUSION

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

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.

Spread of Carbapenem-Resistant Klebsiella pneumoniae in an Intensive Care Unit: A Whole-Genome Sequence-Based Prospective Observational Study

The aim of this study was to determine the contribution of the contamination of the health care environment in the acquisition of carbapenem-resistant Klebsiella pneumoniae (CRKP) in a CRKP-prevalent setting. We performed a 3-month prospective study in a 20-bed medical intensive care unit (ICU) by collecting rectal/oral swabs from patients within 3 days of ICU admission and weekly thereafter. We also comprehensively sampled the beds and rooms of patients and instruments for patient care every week. CRKP were detected, genome sequenced, and assigned to clones based on core genome analyses. The survival of four CRKP clones was determined under ICU conditions. Seventeen patients were in the ICU at the start of the study, and 99 were admitted afterwards. Six were positive patients, with four detected on initial screening and two during weekly monitoring. CRKP was detected from 76 of 3,699 (2.1%) environment samples, including from the immediate surroundings of 21 patients (five had CRKP from clinical samples and 16 did not). CRKP was not detected outside patient care areas. Among 49 CRKP sequenced isolates (nine from swabs, five from clinical samples, and 35 from environment) from 21 patients, 45 were ST11 and had bla_KPC-2. These could be assigned to four clones, with either KL47 (n = 22) or KL64 (n = 23) capsular type. The two dominant clones survived >30 days under ICU conditions. In conclusion, environmental contamination of CRKP was extensive but usually transient. It had little impact on CRKP acquisition by ICU patients, highlighting the ability to control CRKP transmission through infection prevention efforts even in high-prevalence settings.

IMPORTANCEKlebsiella pneumoniae can be an opportunistic pathogen with the oral cavity and gut the main origin. However, carbapenem-resistant Klebsiella pneumoniae (CRKP) can be found in patient surroundings and is a serious threat for human infections. Although the hospital environment, particularly sinks, has long been considered a potential reservoir of CRKP, the exact role of environmental contamination contributing to the acquisition and transmission of CRKP among patients remains largely unknown. To understand the link between environmental contamination in health care settings and colonization and infection of patients by CRKP, we performed a 3-month prospective study in a 20-bed medical ICU. Isolates were collected by active patient screening and were subsequently genome sequenced to describe the diversity of CRKP and the linkage of patients and environmental reservoirs. We found that the environmental contamination of CRKP was extensive, and CRKP clones were freely circulating in the ICU. Environmental contamination was not due to sharing the bed unit or sharing contaminated instruments but more likely resulted from the movement of health care workers. Very few patients acquired CRKP in the ICU, which is likely due to the fact that environmental contamination was usually transient when a routine cleaning protocol was complied. Although CRKP contamination in patient surroundings may be extensive, as long as routine environment cleaning protocols are appropriate and well implemented, the health care environment is unlikely to be a major source of CRKP colonization and infection in ICU patients. Reducing the high workload for ICU nurses may help minimize CRKP environmental contamination.

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.

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.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Performance characteristics and optimal cut-off value of triple adenylate nucleotides test versus adenosine triphosphate test as point-of-care testing for predicting inadequacy of duodenoscope reprocessing

BACKGROUND

Adenosine triphosphate (ATP) test based on one nucleotide has been applied as point-of-care testing (POCT) for bacterial contamination in the medical and food industries. Hypothetically, testing three adenylate nucleotides (A3) may provide better detection of duodenoscope bacterial contamination than ATP test.

AIM

To evaluate performance characteristics and optimal cut-off value of A3 and ATP tests in predicting bacterial contamination of duodenoscopes.

METHODS

Four hundred duodenoscope samples obtained after 100 endoscopic retrograde cholangiopancreatography procedures were randomized into group A (A3 test) or B (ATP test). Samples were collected from the elevator at the four-step cleaning process of duodenoscope. We defined the new cut-off value of the test for reaching 100% negative predictive value (NPV) from our receiver operating characteristic (ROC).

FINDINGS

Using the cultures from the four-step cleaning process as the reference, the areas under ROC (AUROC) were 0.83 and 0.84 for group A (N = 200) and group B (N = 200), respectively. Using the cultures from post-high-level disinfection (HLD) as the reference, the AUROC were 0.35 and 0.74 for group A (N = 50) and group B (N = 50), respectively. We investigated ATP as a POCT after HLD with a new cut-off value of 40 RLU. However, this threshold did not allow detection of low numbers of bacteria.

CONCLUSION

A3 and ATP tests provide good performances in predicting bacterial contamination of duodenoscopes for the four-step cleaning process. The ATP <40 RLU is helpful as a POCT after HLD; however, the limitation of this cut-off value is its inability to detect low numbers of bacteria.

Pseudo-outbreak of Mycobacterium fortuitum in a hospital bronchoscopy unit

BACKGROUND

Mycobacterium fortuitum survive in different environmental conditions, biofilm formation and resistance to chlorinated disinfectants makes its isolation frequent in hospital environments, even being involved in outbreaks by contamination of medical equipment such as bronchoscopes. We describe a pseudo-outbreak by M fortuitum isolated in samples from 9 patients who underwent bronchoscopy in the pneumology bronchoscopy unit of the University Hospital Complex of the Canary Islands from December 2016 to March 2017.

METHODS

We proceeded to investigate the pseudo-outbreak with a combination of epidemiologic, environmental, and molecular typing data.

RESULTS

The source/reservoir of pseudo-outbreak was the hospital water used by the bronchoscope automatic washing machine (without antibacterial filter), so control measures were taken. Molecular typing was performed on 7 strains from 7 patients, and a sample of water was collected from a tap in the pneumology bronchoscopy unit: all of which had the same pattern.

CONCLUSIONS

Our study demonstrates the presence of nontuberculous mycobacteria in the hospital water supply, and thus the need to take measures against them because they compromise patients' health. We also suggest the need for hospital water quality guidelines in which methods to control and/or eliminate them are established.

Infection control in ERCP using a duodenoscope with a disposable cap (ICECAP): rationale for and design of a randomized controlled trial

BACKGROUND

Endoscopic retrograde cholangio-pancreatography (ERCP) is commonly performed in the management of pancreatic and biliary disease. Duodenoscopes are specialized endoscopes used to perform ERCP, and inherent to their design, a high rate of persistent bacterial contamination exists even after automated reprocessing and disinfection. Consequently, in recent years, ERCP has been associated with infection transmission, leading to several fatal patient outbreaks. Due to increasing fears over widespread future duodenoscope-related outbreaks, regulatory bodies have called for alterations in the design of duodenoscopes. A duodenoscope has recently been developed that employs a disposable cap. This novel design theoretically eliminates the mechanism behind persistent bacterial contamination and infection transmission. However, there are no data demonstrating persistent bacterial contamination rates, technical success rates, or clinical outcomes associated with these duodenoscopes.

METHODS

A parallel arm randomized controlled trial will be performed for which 520 patients will be recruited. The study population will consist of consecutive patients undergoing ERCP procedures for any indication at a high-volume tertiary care centre in Calgary, Alberta, Canada. Patients will be randomized to an intervention group, that will undergo ERCP with a novel duodenoscope with disposable cap, or to a control group who will undergo ERCP with a traditional duodenoscope. Co-primary outcomes will include persistent bacterial contamination rates (post automated reprocessing) and ERCP technical success rates. Secondary outcomes include clinical success rates, overall and specific early and late adverse event rates, 30-day mortality and healthcare utilization rates, procedure and reprocessing times, and ease of device use.

DISCUSSION

The ICECAP trial will answer important questions regarding the use of a novel duodenoscope with disposable cap. Specifically, persistent bacterial contamination, technical performance, and relevant clinical outcomes will be assessed. Given the mortality and morbidity burden associated with ERCP-related infectious outbreaks, the results of this study have the capacity to be impactful at an international level.

TRIAL REGISTRATION

This trial was registered on clinicaltrials.gov (NCT04040504) on July 31, 2019.

The importance of sampling technique and rinse water for assessing flexible gastrointestinal endoscope reprocessing: A 3-year study covering 59 centers

BACKGROUND

Various guidelines recommend several sampling techniques to verify endoscope reprocessing, but a comparative study of the efficiency for recovering microorganisms was rare. Our goal was to compare different sampling techniques for the postreprocessing endoscope to assess residual bacterial contamination and analysis of the critical factors affecting the endoscope reprocessing failure.

METHODS

From 2016 to 2018, 3 techniques, the conventional flushing sampling method, flush-brush-flush sampling method (FBFSM), and pump-assisted sampling method (PASM), were compared covering all 59 endoscope units in Tianjin, China.

RESULTS

A total of 237 (84.64%) flushing channel samples and 110 (61.11%) final rinse water samples met the Chinese national standard. The univariate analysis showed that the qualified rates of endoscope reprocessing sampled by PASM (65.52%) and FBFSM (75%) were significantly lower than those of the conventional flushing sampling method (91.38%). Five other factors, including the final rinse water, dry, and hospital level, were potential factors besides sample technique. The multivariate logistic analysis indicated only 2 factors (sampling technique and final rinse water) remained in the model. FBFSM, PASM, and the purified water were significantly associated with the odds of endoscope reprocessing failure, with the odds ratio (95% confidence interval) of which were 4.206 (1.757-10.067), 5.326 (2.463-11.645), and 0.309 (0.137-0.695), respectively.

CONCLUSIONS

The problem of residual microorganisms of the postreprocessing endoscope was severe. Sampling technique and final rinse water were critical for endoscope reprocessing verification.

Bronchoscope-related Pseudomonas aeruginosa pseudo-outbreak attributed to contaminated rinse water

BACKGROUND

Increased percentage of Pseudomonas aeruginosa from bronchoalveolar lavage fluid of patients in June 2016 was observed. P aeruginosa were also obtained from flexible bronchoscope and rinse water in the microbiological surveillance in June 2016.

METHODS

Reprocessing procedure of bronchoscope was assessed, and environmental samples were collected. P aeruginosa isolates recovered from bronchoalveolar lavage fluid of patients between May and September 2016 and environment were characterized using multilocus sequence typing and pulsed-field gel electrophoresis.

RESULTS

A novel multilocus sequence type (ST) of P aeruginosa was defined as ST 2387. ST671 and ST 2387 were both cultured from bronchoscopes and connecting tube in manual reprocessing cleaning equipment. One strain from a patient was indistinguishable from the clones obtained from the bronchoscope and connecting tube revealed by pulsed-field gel electrophoresis. Two strains from 2 patients from the burn intensive care unit were identical, and highly related to 2 other strains from the burn intensive care unit. The persistence of P aeruginosa in bronchoscopes, connecting tubes, and final rinse water was terminated by replacement of the connecting tube.

CONCLUSIONS

We report a pseudo-outbreak of P aeruginosa associated with bronchoscope, for which connecting tube was the hidden reservoir for contaminating bronchoscopes. This highlights that effective measures are needed to control the bacterial load in final rinsing water to protect reusable equipment from contamination in reprocessing and cleaning.

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.

Using Microbiological Sampling to Evaluate the Efficacy of Nasofibroscope Disinfection: The Tristel Trio Wipes System in Ear-Nose-Throat (ENT) Endoscopy

Disinfection and sterilization are needed for guaranteeing that medical and surgical instruments do not spread contagious microorganisms to patients. The aim of this study was to evaluate the efficacy of a simple manual technique of high-level disinfection (HLD) of flexible fiberoptic nasofibroscopes (FFNs) with wipes impregnated with a chlorine dioxide solution (Tristel Trio Wipes System—TTW) against a conventional automated washer machine (Soluscope ENT, Cimrex 12—AW). FFNs used in 62 patients undergoing endoscopy at an ENT clinic were sampled according to an aseptic procedure. For each nasoendoscopy, microbiological samples were taken at two times: (1) after a patient’s nasoendoscopy and (2) immediately after high-level disinfection. Ten microliters of each prepared sample were inoculated onto specific culture media for the detection of nasopharyngeal flora microorganisms. The microbiological results obtained from 62 post-disinfection samples revealed bacterial growth on two FFNs disinfected with AW, and five FFNs disinfected with TTW, but this difference is not statistically significant. None of the isolates were pathogenic bacteria. Our results are different than the results obtained by two previously published studies on the TTW system. In both studies, sampling was carried out by swabbing the tip and the handle surface of FFNs. This sampling method was the least effective method means of detecting bacteria on a surface. It can be concluded that the two disinfection systems allow providers to obtain a reduction of the saprophytic and pathogenic microbial load.

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.

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

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

Scoping the scope: endoscopic evaluation of endoscope working channels with a new high-resolution inspection endoscope (with video)

BACKGROUND AND AIMS

Outbreaks of transmission of infection related to endoscopy despite reported adherence to reprocessing guidelines warrant scrutiny of all potential contributing factors. Recent reports from ambulatory surgery centers indicated widespread significant occult damage within endoscope working channels, raising concerns regarding the potential detrimental impact of this damage on the adequacy of endoscope reprocessing.

METHODS

We inspected working channels of all 68 endoscopes at our academic institution using a novel flexible inspection endoscope. Inspections were recorded and videos reviewed by 3 investigators to evaluate and rate channel damage and/or debris. Working channel rinsates were obtained from all endoscopes, and adenosine triphosphate (ATP) bioluminescence was measured.

RESULTS

Overall endoscope working channel damage was rated as minimal and/or mild and was consistent with expected wear and tear (median 1.59 on our 5-point scale). Our predominant findings included superficial scratches (98.5%) and scratches with adherent peel (76.5%). No channel perforations, stains, or burns were detected. The extent of damage was not predicted by endoscope age. Minor punctate debris was common, and a few small drops of fluid were noted in 42.6% of endoscopes after reprocessing and drying. The presence of residual fluid predicted higher ATP bioluminescence values. The presence of visualized working channel damage or debris was not associated with elevated ATP bioluminescence values.

CONCLUSION

The flexible inspection endoscope enables high-resolution imaging of endoscope working channels and offers endoscopy units an additional modality for endoscope surveillance, potentially complementing bacterial cultures and ATP values. Our study, conducted in a busy academic endoscopy unit, indicated predominately mild damage to endoscope working channels, which did not correlate with elevated ATP values.