Nationwide risk analysis of duodenoscope and linear echoendoscope contamination

A search strategy for detecting duodenoscope-associated infections: a retrospective observational study

BACKGROUND

Duodenoscope-associated infections (DAIs) are exogenous infections resulting from the use of contaminated duodenoscopes. Though numerous outbreaks of DAI have involved multidrug-resistant micro-organisms (MDROs), outbreaks involving non-MDROs are also likely to occur. Detection challenges arise as these infections often resolve before culture or because causative strains are not retained for comparison with duodenoscope strains.

AIM

To identify and analyse DAIs spanning a seven-year period in a tertiary care medical centre.

METHODS

This was a retrospective observational study. Duodenoscope cultures positive for gastrointestinal flora between March 2015 and September 2022 were paired with duodenoscope usage data to identify patients exposed to contaminated duodenoscopes. Analysis encompassed patients treated after a positive duodenoscope culture and those treated within the interval from a negative to a positive culture. Patient identification numbers were cross-referenced with a clinical culture database to identify patients developing infections with matching micro-organisms within one year of their procedure. A 'pair' was established upon a species-level match between duodenoscope and patient cultures. Pairs were further analysed via antibiogram comparison, and by whole-genome sequencing (WGS) to determine genetic relatedness.

FINDINGS

Sixty-eight pairs were identified; of these, 21 exhibited matching antibiograms which underwent WGS, uncovering two genetically closely related pairs categorized as DAIs. Infection onset occurred up to two months post procedure. Both causative agents were non-MDROs.

CONCLUSION

This study provides crucial insights into DAIs caused by non-MDROs and it highlights the challenge of DAI recognition in daily practice. Importantly, the delayed manifestation of the described DAIs suggests a current underestimation of DAI risk.

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.

Effect of a novel endoscope cleaning brush on duodenoscope contamination

BACKGROUND

Current duodenoscope reprocessing protocols are insufficient to prevent contamination and require adaptations to prevent endoscopy-associated infections (EAIs). This study aimed to investigate the effect of a new endoscope cleaning brush on the contamination rate of ready-to-use duodenoscopes.

METHODS

This retrospective before-and-after intervention study collected duodenoscope surveillance culture results from March 2018 to June 2022. Contamination was defined as ≥1 colony-forming unit of a microorganism of gut or oral origin (MGO). In December 2020, an endoscope cleaning brush with a sweeper design was introduced as an intervention in the manual cleaning of duodenoscopes. A logistic mixed-effects model was used to study the effects of this intervention.

RESULTS

Data were collected from 176 culture sets before the new brush's introduction and 81 culture sets afterwards. Pre-introduction, culture sets positive with an MGO comprised 45.5% (95%CI 38.3%-52.8%; 80/176), decreasing to 17.3% (95%CI 10.6%-26.9%; 14/81) after implementation of the new brush. Compared with the former brush, duodenoscopes cleaned with the new brush had lower odds of contamination with MGOs (adjusted odds ratio 0.25, 95%CI 0.11-0.58; P=0.001) CONCLUSIONS: Use of the new brush in manual cleaning reduced contamination with MGOs and is expected to prevent EAIs. These findings should be confirmed in future prospective randomized studies.

Costs of purchase, maintenance, microbiological control, and reprocessing of a reusable duodenoscope

Background and study aims The costs of reusable endoscope reprocessing have been evaluated, yet external validity of the findings remains challenging. The aim of this study was to assess the costs of purchase, maintenance, microbiological control, and reprocessing of a reusable duodenoscope per endoscopic retrograde cholangiopancreatography (ERCP) in France. Study findings exclude the costs of infection, downtime due to breakdown, reprocessing single-use material disposal, and device disposal, all of which should also be considered. Materials and methods The study encompassed both observational and theoretical approaches. Observational data were collected in four hospitals, from December 2019 to December 2020, with an ad hoc survey, based on 2016 and 2018 national guidelines for duodenoscope reprocessing. Costs were modeled, using the same guidelines, assuming a mean workload of 223 ERCP/duodenoscope/year. Results The mean observed cost of purchase, maintenance, microbiological control, reprocessing (human resources and consumables), and overhead (additional 35%) with a reusable duodenoscope was €80.23 (standard deviation €3.77) per ERCP. The corresponding mean theoretical cost was €182.71 for manual reprocessing without endoscope drying cabinet (EDC), €191.36 for manual reprocessing with EDC, €235.25 for automated endoscope reprocessing (AER) without EDC, and €253.62 for AER with EDC. Conclusions Because procedures, equipment, volume activity, number of duodenoscopes, human resources, and internal work organizations are hospital-dependent, observed costs varied between hospitals. Theoretical costs were higher than observed costs, showing that the theoretical approach is not sufficient. Hypotheses to explain the difference between the two approaches include failing to measure some costs in the survey and challenges in guideline implementation.

Endoscopic retrograde cholangiopancreatography and endoscopic ultrasound endoscope reprocessing: Variables impacting contamination risk

OBJECTIVE

To evaluate variables that affect risk of contamination for endoscopic retrograde cholangiopancreatography and endoscopic ultrasound endoscopes.

DESIGN

Observational, quality improvement study.

SETTING

University medical center with a gastrointestinal endoscopy service performing ∼1,000 endoscopic retrograde cholangiopancreatography and ∼1,000 endoscopic ultrasound endoscope procedures annually.

METHODS

Duodenoscope and linear echoendoscope sampling (from the elevator mechanism and instrument channel) was performed from June 2020 through September 2021. Operational changes during this period included standard reprocessing with high-level disinfection with ethylene oxide gas sterilization (HLD-ETO) was switched to double high-level disinfection (dHLD) (June 16, 2020-July 15, 2020), and duodenoscopes changed to disposable tip model (March 2021). The frequency of contamination for the co-primary outcomes were characterized by calculated risk ratios.

RESULTS

The overall pathogenic contamination rate was 4.72% (6 of 127). Compared to duodenoscopes, linear echoendoscopes had a contamination risk ratio of 3.64 (95% confidence interval [CI], 0.69-19.1). Reprocessing using HLD-ETO was associated with a contamination risk ratio of 0.29 (95% CI, 0.06-1.54). Linear echoendoscopes undergoing dHLD had the highest risk of contamination (2 of 18, 11.1%), and duodenoscopes undergoing HLD-ETO and the lowest risk of contamination (0 of 53, 0%). Duodenoscopes with a disposable tip had a 0% contamination rate (0 of 27).

CONCLUSIONS

We did not detect a significant reduction in endoscope contamination using HLD-ETO versus dHLD reprocessing. Linear echoendoscopes have a risk of contamination similar to that of duodenoscopes. Disposable tips may reduce the risk of duodenoscope contamination.

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.

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.

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.

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 duodenoscope for ERCP performed by endoscopists with a range of experience in procedures of variable complexity

BACKGROUND AND AIMS

Expert endoscopists previously reported ERCP outcomes for the first commercialized single-use duodenoscope. We aimed to document usability of this device by endoscopists with different levels of ERCP experience.

METHODS

Fourteen "expert" (>2000 lifetime ERCPs) and 5 "less-expert" endoscopists performed consecutive ERCPs in patients without altered pancreaticobiliary anatomy. Outcomes included ERCP completion for the intended indication, rate of crossover to another endoscope, device performance ratings, and serious adverse events.

RESULTS

Two hundred ERCPs including 81 (40.5%) with high complexity (American Society for Gastrointestinal Endoscopy grades 3-4) were performed. Crossover rate (11.3% vs 2.5%, P = .131), ERCP completion rate (regardless of crossovers) (96.3% vs 97.5%, P = .999), median ERCP completion time (25.0 vs 28.5 minutes, P = .130), mean cannulation attempts (2.8 vs 2.8, P = .954), and median overall satisfaction with the single-use duodenoscope (8.0 vs 8.0 [range, 1.0-10.0], P = .840) were similar for expert versus less-expert endoscopists, respectively. The same metrics were similar by procedural complexity except for shorter median completion time for grades 1 to 2 versus grades 3 to 4 (P < .001). Serious adverse events were reported in 13 patients (6.5%).

CONCLUSIONS

In consecutive ERCPs including high complexity procedures, endoscopists with varying ERCP experience had good procedural success and reported high device performance ratings. (Clinical trial registration number: NCT04223830.).

Single-use duodenoscopes: where are we and where are we going?

PURPOSE OF REVIEW

Given the growing concerns about infection transmission from use of contaminated reusable duodenoscopes, technological advancements have been made that vary from modifications of existing designs to development of single-use devices.

RECENT FINDINGS

To circumvent mechanical limitations that preclude access to critical areas of a duodenoscope to perform thorough cleaning and disinfection, single-use disposable duodenoscopes have been developed. A thorough assessment of this technology is limited by the minimal published data that is currently available. This opinion assesses the current technical functionality of these devices, potential for further improvements, implications for healthcare economics and the future of gastrointestinal endoscopy.

SUMMARY

Currently available data suggest that majority of endoscopic retrograde cholangiopancreatography procedures can be safely performed using single-use duodenoscopes. The ability to improve technical functionality, incorporate futuristic technology and secure financial reimbursement from insurance carriers will largely define the future prospects of this recent innovation.

A nationwide survey on the effectiveness of training on endoscope reprocessing within the national cancer screening program in Korea

BACKGROUND

The National Cancer Center has provided nationwide endoscope reprocessing training to hospitals annually performing national gastric and colorectal cancer screening in Korea since 2012. This study aimed to evaluate the adherence of past participants of endoscope reprocessing training to the reprocessing guidelines and their satisfaction with the current training.

METHODS

Training on endoscope reprocessing was implemented 18 times across the country, from June 2019 to November 2019. Immediately after the training, participants filled a paper questionnaire related to reprocessing practices and satisfaction with the current training anonymously.

RESULTS

A total of 1,132 participants trained responded to the survey (response rate, 95.4%). Of the study participants, 45.7% participated in the past endoscope reprocessing training, and 94.6% of them answered that they have adhered to the endoscope reprocessing guidelines. Experience of participation in endoscope reprocessing training was significantly associated with practical adherence to endoscope reprocessing guidelines (aOR, 6.55; 95% CI, 3.93 to 10.91). And, 91% of study participants were satisfied with the current endoscope reprocessing training.

CONCLUSIONS

The current training on endoscope reprocessing provided at the national level could help ensure adherence to reprocessing guidelines, resulting in obtaining quality control for endoscopy. However, about half of practitioners currently working in endoscopy units had not received sufficient reprocessing training, and thus more training is needed for them.

Microbiological Surveillance of Endoscopes in a Southern Italian Transplantation Hospital: A Retrospective Study from 2016 to 2019

Endoscopes are medical instruments that are used routinely in health structures. Due to their invasive nature and contact with many patients, they may cause hospital-acquired infections if not disinfected correctly. To ensure a high-level disinfection procedure or reprocessing, since the methods currently adopted in our institute are adequate, we evaluated retrospectively the presence of microorganisms in our endoscopes after reprocessing. Microbiological surveillance was performed from January 2016 to December 2019 in the instruments in use in our endoscopic room after reprocessing. In total, 35 endoscopes (3 duodenoscopes, 3 echoendoscopes, 12 bronchoscopes, 5 colonoscopes, and 12 gastroscopes) were evaluated for the presence of microorganisms, including multidrug-resistant pathogens and indicator microorganisms (IMOs). Our procedures were in agreement with an internal protocol based on Italian, international, and the Center for Disease Control and Prevention (CDC) recommendations. Of a total of 811 samples, 799 (98.5%) complied with the regulatory guidelines, while 9 (1.1%) were positive for IMOs, and 3 (0.4%) displayed more than 10 colony-forming units (CFU) of environmental and commensal pathogens. Our results show that the internal reprocessing protocol is very efficient, leading to a very low number of observed contaminations, and it could be easily implemented by other health facilities that face a huge number of hospital-acquired infections due to incorrectly disinfected endoscopes.