Culture, quarantine effectively identify contaminated duodenoscopes
First and even second time high-level disinfection may not be enough to eliminate bacterial contamination in duodenoscopes, but a culture and quarantine program can help identify which scopes need more attention, according to study results.
“Because of the concerns of duodenoscope-transmitted infections, in 2015 our institution re-evaluated duodenoscope cleaning and reprocessing practices and instituted [high-level disinfection] followed by a culture and quarantine protocol to decrease risks of infection,” Jacob Mark, MD, of the division of pediatric gastroenterology, hepatology and nutrition at Children’s Hospital Colorado, and colleagues wrote. “This study aimed to evaluate the results of this protocol and with culture results and active monitoring for duodenoscope-transmitted infections.”
After each use, duodenoscopes underwent high-level disinfection (HLD) according to manufacturer protocols. Researchers collected culture specimens from the scopes and quarantined them until they obtained the culture results. If a culture returned positive — defined as more than 10 colony-forming units (CFUs) of low concern organisms or any CFUs of high-concern according to CDC recommendations — they repeated the HDL process until cultures were negative.
Between 2015 and 2018, Mark and colleagues cleaned 140 duodenoscopes and obtained 280 culture specimens. Out of 234 initial cultures, 28 were positive (12%). Of 36 second cultures, five were positive (14%), and of eight third cultures, two were positive (25%). None of the patients had infections related to an ERCP procedure.
During the study, there was just one duodenoscope that had positive cultures after a third cleaning. After sending it back to the manufacturer, researchers found that it had cracks in the casing at the tip that harbored bacteria for colonization. After repair, it no longer had consistently positive cultures.
Mark and colleagues wrote that their findings show that duodenoscopes are unlikely to remain contaminated after a third round of HLD. Although the FDA has recently recommended a transition to duodenoscopes with disposable components, the authors wrote that additional steps in cleaning can still be a part of regular scope maintenance.
“Likely the ultimate solution to this problem will be change in duodenoscope design,” they wrote. “Until then, health care facilities must take additional steps such as regular culturing and quarantine to ensure the current equipment is as safe as possible for patients who need ERCP.” – by Alex Young
Disclosure: The authors report no relevant financial disclosures.