Effect of enzyme cleaning and EOW on complete immersion disinfection of gastroscope

Objective The aim of the investigation is to examine the efficacy of enzyme cleaning and electrolyzed oxidizing water (EOW) on complete immersion disinfection of gastroscope. Methods 120 patients accepted gastroscopy were divided into enzyme cleaning group (60 patients) and flowing water cleaning group (60 patients). To check the effect of washing, specimens were collected from operating part, endoscopic surface, and biopsy channel before and after enzyme cleaning and flowing water cleaning for bacterial culture. Gastroscopes of each group were divided into 2 min and 4 min group (30 patients for each group) for the different EOW disinfection time. Specimens were collected from operating part, endoscopic surface, and biopsy channel after EOW disinfection for 2 min or 4 min. Results Specimens collected from 115 (95.8%) on operating part and 120(100%) on endoscopic surface and biopsy channel were positive in culture before cleaning. The numbers of positive culture were 11(18.3%) on operating part and 14(23.3%) on endoscopic surface and biopsy channel in enzyme cleaning group after cleaning, but 19(31.7%) and 26(43.3%) in flowing water cleaning group, respectively(P 0.05). No positive culture was found on operating part, endoscopic surface and biopsy channel in enzyme cleaning group after disinfection 2 min, but in flowing water cleaning group, 7(23.3%) and 6(20.0%)were positive, respectively. There was significant difference between enzyme cleaning group and flowing water cleaning group after disinfection 2 min. Positive culture rate of specimens in operating part, endoscopic surface and biopsy channel was absent in both groups after EOW disinfection for 4 min. Conclusion Enzyme cleaning can clean gastroscopes thoroughly,and gastroscopes disinfected in EOW for 4 min is effective and can achieve disinfection standard.