Detection of the intragastric sites at which Helicobacter pylori evades treatment with amoxycillin and cimetidine.

Treatment of Helicobacter pylori infection with amoxycillin is known to reduce the bacterial load to undetectable levels, while not eradicating the infection. It seems, therefore, that bacteria escape treatment at a 'sanctuary site'. This study examined whether such a site existed in the gastric antrum, body, or fundus. Twenty two patients with H pylori infection and duodenal ulcer disease were treated for one week with amoxycillin (500 mg three times a day) and cimetidine (800 mg at night). Before treatment, H pylori was detected throughout all stomachs, and 13C-urea breath testing at least 28 days after treatment confirmed that eradication of H pylori had occurred in no patients. While under treatment, H pylori was sought by conventional methods and by polymerase chain reaction assay and was found in the gastric fundus in 13 of 22 subjects, in the body in 10 of 22, and the antrum in three of 22: the difference between fundus and antrum was significant (p < 0.01). The continued antral infection in three subjects may have resulted from generalised treatment failure as two of three had H pylori detected throughout the stomach, and these two had compiled relatively poorly with treatment. This study suggests that amoxycillin and cimetidine are relatively effective at clearing H pylori from the gastric antrum, but that escape from treatment may occur in the gastric body, and especially the fundus.