Monitoring quality of flexible endoscope disinfection by microbiologic surveillance cultures.

Background: The purpose of this study is to assess the adequacy of currently approved high-level disinfection (HLD) for flexible endoscopes, by reviewing retrospectively the results of environmental cultures on the endoscopes, which were ready to use.

Methods: Cultures of all of our gastrointestinal endoscopes that were ready for use were sent to the laboratory for environmental cultures. Thirty milliliters of sterile water was passed through the biopsy channel of the endoscopes and the flushed water was collected in a sterile container. The specimen was plated onto blood agar, incubated at 37C, and examined for growth at 24 and 48 hours.

Results: Cultures were positive during the initial part of the study repeatedly with the same organism; the source of contamination was traced to be the source water and scope cleaner, after they were suspected and sent for cultures. In addition to Pseudomonas, there was contamination of the endoscopes with Micrococcus and Staphylococcus during the study period.

Conclusions: Using environmental cultures for monitoring effectiveness of standard reprocessing procedures on a regular basis in clinical practice is not only inexpensive but also valuable to identify the source of possible contamination and rectify reprocessing methods to prevent transmission of infection secondary to endoscopy.