Evaluation of endoscopic processing on the potential for Clostridiodes difficile transmission

Clostridiodes difficile (CD) is a common healthcare-associated infection (HAI). CD is a spore-forming pathogen that is hard to remove from environmental surfaces and equipment. Endoscopes are essential reusable medical equipment for diagnostic and therapeutic indications. The primary aim of this study was to evaluate the efficacy of the colonoscope disinfection process on the ability to eliminate CD. A secondary aim was to further look at the prevalence of CD colonisation as well as toxin presence in the sample population. A convenience sample of 100 colonoscopic procedures were included. The colonoscopes were flushed with 50 ml of sterile water before and after high-level disinfection (HLD). Both samples were subjected to DNA extraction and quantification, followed by qPCR testing. The electronic health records (EHR) were reviewed for clinical and demographic information. The mean age of patients was 57 years with an average time for colonoscopic procedure of 37 minutes. One patient was known to have CD infection prior to this colonoscopy. Aerobic culture broth was positive in 29% of cases in pre-HLD samples, while none were culture positive after HLD. Thirty-one (57.41%) samples were positive by qPCR , and 15 (48.39%) remained positive after HLD. The cycle threshold value and DNA quantification were lower after HLD. There is a high prevalence of CD asymptomatic colonisation among patients undergoing colonoscopic examination. HLD was effective in reducing, but not eliminating, CD. The presence of low DNA quantity cannot be translated to increased risk of transmission, especially with negative cultures.