Do conventional cleaning and disinfection techniques avoid the risk of endoscopic Helicobacter pylori transmission?

The aim of the present study was to determine whether endoscopes serve as a reservoir for Helicobacter pylori and whether the disinfection technique currently recommended for manual cleaning and disinfection of the instruments completely removes the risk of H. pylori transmission.

A prospective study was carried out in 400 patients who were undergoing upper gastrointestinal endoscopy for routine clinical indications. The patients' H. pylori status of the patients was identified using a urea detection system (HUT) and culture. H. pylori contamination was assayed by culturing rinsing samples from the endoscopes before and after manual cleaning and disinfection. Gastric biopsies were assayed using rapid urease testing (Helicobacter urease test, HUT) of two antral and gastric body biopsies and cultures.

A total of 128 of the 400 patients examined were found to be H. pylori-positive using HUT testing. Endoscopes were contaminated in 54 of the 128 rinsing samples from endoscopes used in H. pylori-positive patients (42 %) before cleaning and disinfection. One of the 128 rinsing samples (0.8 %) was found to be contaminated with H. pylori even after routine manual cleaning and disinfection - indicating that these cleaning and disinfection procedures may be insufficient to eradicate H. pylori from endoscopes completely. No seroconversion was observed during serological follow-up in the patient who had previously been examined with an endoscope contaminated with H. pylori. The patient was still found to be seronegative 5 months after inoculation.

Endoscopes are frequently contaminated with H. pylori immediately after gastroduodenal endoscopy in H. pylori-infected patients. Iatrogenic transmission is possible, as H. pylori can survive manual cleaning and disinfection with 2 % glutaraldehyde, particularly when there is ineffective cleaning before disinfection.