Pitfalls in endoscope reprocessing: brushing of air and water channels is mandatory for high-level disinfection

Abstract

Background: Endoscopic transmission of pathogens has been reported. Guidelines have been formulated concerning the risk of infection via contaminated suction and accessory channels. Contamination of the other 2 channels for air and water has not been demonstrated. These channels were examined to clarify whether they require cleaning. Methods: Endoscopes used for examinations were divided into 2 groups. Group A endoscopes (n = 20) were brushed along the air and water channels. Group B endoscopes (n = 22) were not. After machine reprocessing, specimens were obtained for bacterial culture. The residual protein was measured in the 2 channels by using amido black 10B dye, and results were compared between the 2 groups. Results: With regard to the air channel, there were no contaminated endoscopes detected in either group. For the water channel, 1 endoscope in group B was positive whereas there were none positive in group A. With regard to quantification of residual protein, brushing diminished the level in both the air and the water channels. Conclusion: The air and water channels can become contaminated. Brushing every channel is mandatory for high-level disinfection. A redesign of the fundamental structure of endoscopes is proposed. (Gastrointest Endosc 2001;53:165-8.)