SIGNIFICANT FACTORS IN THE DISINFECTION AND STERILIZATION OF FLEXIBLE ENDOSCOPES

Background: Many nosocomial infection outbreaks have been linked to improper disinfection of the flexible endoscopes used in hospitals and clinics. The objective of this study was to evaluate the efficacy of scope disinfection with glutaraldehyde and hydrogen peroxide in manual and mechanical protocols. Methods: Bacillus subtilis and Pseudomonas cepacia were the test organisms. Each channel in two different endoscopes was seeded and evaluated separately. Residual chemical germicide levels in the channels and in the work environment were also measured. Results: Parametric analyses were carried out on log transformations of number of colony-forming units recovered. Repeated measures analysis demonstrated that both the type of disinfectant and the method of washing were significant factors for disinfection. Conclusions: Hydrogen peroxide proved to be more efficacious than glutaraldehyde for killing or removing B. subtilis in a 10-minute contact period. Automatic disinfection was more efficacious than manual disinfection for killing or removing B. subtilis in a 10-minute contact period. The channel being disinfected also proved to be a significant factor, with carbon dioxide and elevator channels the most difficult to disinfect consistently.