Helicobacter pylori may be transmitted through gastrofiberscope even after manual Hyamine washing.

Endoscopy is an effective diagnostic technique for gastric cancer, which is believed to be associated with Helicobacter pylori. Manual Hyamine washing is a widely used fiberscope cleaning method. Urease B gene of Helicobacter pylori was detected in 50% of the wash-out samples from the biopsy-suction channel of a fiberscope after manual Hyamine washing by nested polymerase chain reaction, and bacterial culture revealed viable Helicobacter pylori in 19%. However, Helicobacter pylori was not detected by either of the above methods in the biopsy-suction channel of the fiberscope after mechanical washing. These findings indicate that manual Hyamine washing of fiberscopes is insufficient to prevent iatrogenic Helicobacter pylori transmission, and that mechanical washing after manual Hyamine washing is essential.