Disinfection Efficacy of a New Endoscope Reprocessing System Using Electrolyzed Acid Water: An In-Use Evaluation

Lee, Jun Haeng; Rhee, Poong Lyul; Song, Jae Hoon; Lee, Nam Yong; Lim, Yun Jeong; Jang, Jae Kwon; Kim, Young Ho; Kim, Jae Jun; Paik, Seung Woon; Rhee, Jong Chul; Choi, Kyoo Wan

Abstract

BACKGROUND: Electrolyzed acid water (EAW) is a new liquid chemical germicide containing a mixture of oxidizing species and prepared by mixing a small amount of salt with tap water in an electrolyzer. We attempted an in-use evaluation of the high-level disinfection capability of Cleantop WM-1 , a new endoscope reprocessing system using EAW. METHODS: Forty-seven flexible endoscopes were randomly collected just after upper endoscopic examinations and were disinfected using Cleantop WM-1 . Parts of the endoscopes without contact to EAW were disinfected with 75% ethyl alcohol. Immediately after the disinfection procedure, samples were taken from the biopsy channel (S-1), tip of the insertion tube (S- 2), the umbilical cord (S-3), and the angulation knob (S-4). RESULTS: In EAW-disinfected parts of the endoscopes, the culture-positive rates were 4.3% (2/47) in S-1 samples and 12.8% (6/47) in S-2 samples. In ethyl alcohol-disinfected area, the culture-positive rates were 2.1% (1/47) in S-3 samples and 25.5% (12/47) in S-4 samples. The colony counts of culture-positive samples ranged from 1 to 144. Pseudomonas aeruginasa was recovered from the angulation knob of an endoscope, but other contaminating organisms were mostly: normal flora or opportunistic pathogens. CONCLUSOIN: Although parts of the endoscopes disinfected with 75% ethyl alcohol were contaminated with more organisms than EAW-disinfected areas, Cleantop WM-1 showed a relatively good disinfection efficacy in reprocessing patient-used endoscopes.