ASM Microbe
ASM Microbe
June 24, 2016
1 min read

Duodenoscope surveillance uncovers processing challenges

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BOSTON — Periodic surveillance of duodenoscope cultures revealed that some devices are susceptible to persistent contamination despite undergoing standard reprocessing protocols, according to data presented at ASM Microbe 2016.

Disha Sampat, MPH, infection preventionist with Memorial Hermann-Texas Medical Center, and colleagues launched an investigation at their facility to provide logistical processes for a successful duodenoscope surveillance program and to assess the prevalence of contamination after the devices were reprocessed. 

Each month from June to November 2015, two operators wearing personal protective equipment collected cultures from the facility’s duodenoscopes. The operators sanitized the scopes’ outer surface and elevator with an alcohol swab and sterile brushes pre-moistened with sterile 0.01M phosphate buffered saline with 0.02% Tween-80 solution. They then obtained three samples from each duodenoscope from the elevator-closed position, elevator-opened position and from the channel, and flushed 50 mL of sterile water through the biopsy valve, collecting it into a sterile container.

To avoid interruption to workflow, the duodenoscopes were taken out of rotation for surveillance during the weekends. The devices were tested on Fridays and not used until they yielded negative results and were cleared by infection prevention on Monday. Any scopes positive for bacteria resulted in a chart review to determine which patients were at risk for post-procedure infections.

Of the 32 cultures obtained during the investigation, three tested positive for either Pseudomonas aeruginosa (n = 2) or Streptococcus. One duodenoscope consistently tested positive for P. aeruginosa and was sent back to the manufacturer. However, there were no post-procedure cases of bacteremia or cholangitis.

Sampat and colleagues concluded that surveillance of duodenoscope contamination is feasible and clinically relevant; however, current methods used to reprocess the scopes are inadequate. They called for the development of newer and more effective reprocessing techniques, including those that do not require culturing in order to rapidly detect contamination and reduce the amount of time a duodenoscope is out of use. – by Stephanie Viguers


Sampat D, et al. Early results of a duodenoscope microbiological surveillance program. Presented at: ASM Microbe; June 16-20, 2016; Boston.

Disclosure: The researchers report no relevant financial disclosures.