Reinfection or recrudescence after apparently successful eradication of Helicobacter pylori infection: implications for treatment of patients with duodenal ulcer disease.

Helicobacter pyloris is considered to be aetiologically implicated in gastritis and peptic ulceration, since if H. pyloris infection can be eradicated the risk of subsequent ulcer relapse is markedly reduced. The rate of 'reinfection' following treatment ranges from 0% to 45%, but its origin remains controversial (reappearance of uneradicated original infection or a fresh infection). To distinguish temporary suppression of H. pylori from fresh infection we conducted a retrospective analysis of the criteria used to establish eradication of the original infection in 304 patients. We used the [14C]urea breath test, in which an integrated area under the curve (AUC) value of < 40 in 2 h is considered to indicate eradication of H. pylori in patients tested 1 month after treatment. The results suggest that relapsed infection with H. pylori usually represents recrudescence of the original infection rather than a fresh infection; there was a higher relapse rate in patients with a breath test AUC > 20 < 40, compared with those with an AUC < 20. All 'reinfections' occurred within 24 months of the original treatment. 'Reinfection' was uncommon in patients receiving powerful therapeutic regimens (e.g. triple therapy) compared with those receiving monotherapy or relatively ineffective dual therapy combinations. In patients whose urea breath test remains negative 12 months after treatment the subsequent reinfection rate is only 0.44%/year. This supports the strategy of eradicating H. pylori infection from suitable peptic ulcer patients.