In a cleaning and disinfection process that requires 50 to 100 individual steps, a lot of things can go wrong.

Five years of extensive auditing of reprocessing protocols at a university hospital in Italy showed that even seemingly small infractions can make a big difference in duodenoscope reprocessing success.

A new study in the International Journal of Environmental Research and Public Health documents how an Italian hospital went from a 100 percent contamination rate for duodenoscopes post-reprocessing to a 23 percent rate, using microbial surveillance to analyze and improve upon cleaning and disinfection of the scopes.

Dr. Beatrice Casini was the lead author for “Improving the Reprocessing Quality of Flexible Thermolabile Endoscopes: How to Learn from Mistakes” which published in March 2021.

In the beginning of the study period, August 2014, all tested patient-ready duodenoscopes were found non-compliant, and a majority had high-concern organisms (HCOs) on internal channels. Corrective actions were taken, and the non-compliant number fell to about 70 percent of duodenoscopes, though still the majority of those contaminated showed evidence for high-concern organisms.

Another round of reprocessing improvements reduced the non-compliance number to 23 percent of duodenoscopes, and very few had HCOs at the end of the study period (December 2019).

Unlike what may have been expected based on previous studies and general concern for duodenoscope’s elevator mechanism, the contamination was mostly traced back to the internal channels of the duodenoscopes.

Casini and her team discovered in their audits several ways in which reprocessing protocol was not being strictly followed:

• Wash basins were not large enough for full immersion of scopes during manual cleaning, as required by manufacturer instructions for use.
• Cleaning brushes were used several times before being disinfected.  
• An established dirty-to-clean pathway in the reprocessing unit did not exist to help limit cross-contamination in sterile processing.
• The internal surfaces of storage cabinets were not disinfected at any regular interval.
• There was no way to verify storage time for endoscopes, leading to some being stored for more than three days and risking microbial growth.  

Researchers also found that during after-hours emergency cases, manual cleaning of duodenoscopes often did not start in the recommended 30-minute window following procedures. As a result, the university hospital instituted a new protocol to speed delivery to the reprocessing room.

The university also instituted new, and more frequent, training of reprocessing personnel and introduced new filtration systems to help address many of the water contamination problems found during the audit.

Duodenoscopes are the only flexible endoscopes with formal recommendations for microbial surveillance following reprocessing in the U.S.

The authors argue for regular surveillance following reprocessing of duodenoscopes and regular training of reprocessing personnel.  

“Although this risk assessment and management approach is costly in terms of human and economic resources … it is considered the most cost-effective approach for mitigating carbapenem-resistant Enterobacteria (CRE) transmission risks during ERCP in settings with extremely high CRE prevalence,” according to the study.

Estimated contamination rates of duodenoscopes vary, but a recent meta-analysis in The Lancet found a potential rate to be more than 15 percent. The U.S. Food and Drug Administration estimates 5.4 percent of patient-ready duodenoscopes may have lingering contaminants on them. That's based on medical device reports collected between October 2018 and November 2019.