Factors affecting the variation in antibiotic resistance of Helicobacter pylori over a 3-year period.

Strains of Helicobacter pylori, isolated from 300 patients between 1996 and 2000 were tested for their sensitivity to clarithromycin, metronidazole and amoxycillin. Primary resistances (95% CI) were 9. 7% for clarithromycin and 21.7% for metronidazole. No strains were resistant to amoxycillin. There was no significant difference between the number of resistant strains in the male and female groups. Clarithromycin resistance was more common in older patients (P<0.01) and metronidazole resistance was more common in patients with peptic ulcer compared with patients with chronic gastritis (P<0. 05). Logistic regression analysis confirmed these results.