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.

A Search Strategy for Detecting Duodenoscope-Associated Infections: A Retrospective Observational Study

BACKGROUND

Duodenoscope-associated infections (DAI) are exogenous infections resulting from the use of contaminated duodenoscopes. While numerous outbreaks of DAI involved multidrug-resistant microorganisms (MDRO), outbreaks involving non-MDRO 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. This retrospective observational study aims to identify and analyse DAIs spanning a seven-year period.

METHODS

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. Our 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 microorganisms 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 whole-genome sequencing (WGS) to determine genetic relatedness.

FINDINGS

A total of 68 pairs were identified, and among them, 21 exhibited matching antibiograms. These pairs underwent WGS, which uncovered two genetically closely related pairs categorized as DAIs. Infection onset occurred up to two months post-procedure. Both causative agents were non-MDRO.

CONCLUSIONS

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

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.

Performance of a single-use gastroscope for esophagogastroduodenoscopy: Prospective evaluation

Background and study aims Reprocessing reusable endoscopes is challenging due to their non-sterilizable nature. Disinfection has been shown to have a significant risk of failure with serious consequences. Single-use endoscopes can eliminate contamination risk and reduce workflow delays caused by reprocessing. This study evaluated the clinical performance of single-use gastroscopes in patients undergoing esophagogastroduodenoscopy (EGD). Patients and methods In this case series, 60 patients underwent EGD using single-use gastroscopes, with 34 procedures in the endoscopy department and 26 in the intensive care unit. The primary outcome was successful completion of the intended EGD objective. Furthermore, certified endoscopists assessed device performance on a five-point Likert scale (ranging from 1-"much worse" to 5-"much better"), considering their experience with a reusable gastroscope. Results Successful completion of EGDs using only the single-use gastroscope was achieved in 58 of 60 cases (96.7%). In two cases, crossover to an ultra-slim endoscope was necessary to either reach the esophageal stenosis or to transverse the stenosis. Overall satisfaction was rated as comparable to reusable scopes in 51 of 56 cases (91.1%) and inferior in five cases (8.9%). The lower weight of the single-use gastroscope was rated as superior in 42 of 60 cases (70.0%). Drawbacks included reduced image quality (23 of 45 cases; 51.1%). Feedback included the absence of a freeze button, lens cleaning issues, and small image size. Conclusions Single-use gastroscopes exhibited a high EGD completion rate and effectiveness for various indications. Further research should focus on evaluating the implementation of single-use gastroscopes in a comprehensive context, considering clinical effectiveness, costs, and environmental impact.