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


CONCLUSIONS
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.
Ishino
Y
Y
Department of Gastroenterology, Jichi Medical School, Tochigi, Japan.
Ido
K
K
Koiwai
H
H
Sugano
K
K
D000388:Air; D004203:Disinfection / Q000379:methods*; D020776:Endoscopes, Gastrointestinal / Q000592:standards*; D017743:Equipment Reuse / Q000592:standards*; D006801:Humans; D014867:Water
D014867:Water