High prevalence of Helicobacter pylori metronidazole resistance in migrants to east London: relation with previous nitroimidazole exposure and gastroduodenal disease.

A high prevalence of metronidazole resistance in Helicobacter pylori is reported in developing countries. This study examined whether migrants referred for diagnostic gastroscopy at a United Kingdom centre (n = 54), had a higher prevalence of metronidazole resistance than subjects born in the United Kingdom attending endoscopy (n = 46). Records of nitroimidazole treatment prescribed in the United Kingdom was obtained in 83 patients to find out if there was an association between H pylori metronidazole resistance and previous ingestion of either metronidazole or tinidazole. The prevalence of metronidazole resistant isolates varied according to country of birth: Bangladesh (90%, 27 of 30), other countries (67%, 16 of 24), and United Kingdom (37%, 17 of 46) (p < 0.001). Among those born in the United Kingdom, women were more likely to harbour resistant H pylori than men (54% v 18% respectively, p = 0.01) and more likely to have a history of previous nitroimidazole ingestion (41% v 11% respectively, p = 0.02). Patients previously exposed to either metronidazole or tinidazole were more likely to harbour resistant strains (84% (27 of 32) v 41% (21 or 51), p < 0.0001). The distribution of gastroduodenal disease, assessed endoscopically, was not affected by metronidazole resistance status.