The problem of cross contamination by endoscopes

​​This week, Prof Marco Bruno, Department of Gastroenterology and Hepatology at the Erasmus University Medical Centre in Rotterdam is explaining about the problem we have with scope contamination.  Last year his department published a Nationwide Study of bacterial colonization of endoscopes. The study included 74 Dutch Centres and reported that 17% of duodenoscopes and 13% of EUS scopes were contaminated!   We should all be concerned because when a contaminated endoscope is used, the risk of harm to a patient may be as great as 10%!  What can we do about this ?

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​Rauwers AW. Dutch analysis of risks of contamination with duodenoscopes and EUS. GIE 2020;92;681-91

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 w15% was similarly high for duodenoscopes as for linear
echoendoscopes, rendering patients undergoing ERCP and EUS at risk for transmission of microorganisms.

​Ofstead CL. Review of infections after ERCP. End Int Open 2020;08;E1769-81

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 multi society 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.

​Editorial; Scoping the problem endoscopy-associated infections. Lancet Gastro Hep 2018;3;445

Bang JY. Single-use duodenoscopes. Gut 2020;0;1-7

Objective Single-use duodenoscopes have been recently developed to eliminate risk of infection transmission from contaminated reusable duodenoscopes. We compared performances of single-use and reusable duodenoscopes in patients undergoing endoscopic retrograde cholangiopancreatography (ERCP).
Design Patients with native papilla requiring ERCP were randomised to single-use or reusable duodenoscope. Primary outcome was comparing number of attempts to achieve successful cannulation of desired duct. Secondary outcomes were technical performance that measured duodenoscope manoeuvrability, mechanical-imaging characteristics and ability to perform therapeutic interventions, need for advanced cannulation techniques or cross-over to alternate duodenoscope group to achieve ductal access and adverse events.
Results 98 patients were treated using single-use (n=48) or reusable (n=50) duodenoscopes with >80% graded as low-complexity procedures. While median number of attempts to achieve successful cannulation was significantly lower for single-use cohort (2 vs 5, p=0.013), ease of passage into stomach (p=0.047), image quality (p<0.001), image stability (p<0.001) and air–water button functionality (p<0.001) were significantly worse. There was no significant difference in rate of cannulation, adverse events including mortality (one patient in each group), need to cross-over or need for advanced cannulation techniques to achieve ductal access, between cohorts. On multivariate logistic regression analysis, only duodenoscope type (single-use) was associated with less than six attempts to achieve selective cannulation (p=0.012), when adjusted for patient demographics, procedural complexity and type of intervention.
Conclusion Given the overall safety profile and similar technical performance, single-use duodenoscopes represent an alternative to reusable duodenoscopes for performing low-complexity ERCP procedures in experienced hands

Pentax Youtube clip with Marco on the topic scope contamination