Occurrence of New Helicobacter pylori Infections in Healthy, Helicobacter pylori-Negative Adults: A Prospective Observational Study.

OBJECTIVES: The annual incidence of new Helicobacter pylori infections evaluated by serological test in Korean adults has been reported to be 2.1%-3.3%. This study evaluated the rate of new H. pylori infections using the urea breath test (UBT) and the factors associated with new infection. METHODS: In this prospective observational study, we recruited participants from the National Cancer Screening Program who tested negative for H. pylori infection by both rapid urease test and histology between November 2007 and December 2014. The participants underwent the UBT to check their follow-up H. pylori infection status from August 2015 to December 2017. The primary outcome of this study was new H. pylori infection. RESULTS: A total of 192 participants were enrolled in this study. During the mean follow-up of 4.1 years from the initial negative tests for H. pylori infection, a new infection occurred in six participants (3.1%, 6/192 participants). According to analyses using the logistic regression model, age (odds ratio [OR], 1.13; 95% confidence interval [CI], 1.02-1.26) and corpus atrophy (OR, 9.83; 95% CI, 1.59-60.98) were associated with the new H. pylori infection in univariate analyses. However, no significant factors were identified in multivariate analysis. CONCLUSIONS: New H. pylori infection rarely occurred in Korean adults, with a rate of 3.1%. However, no independent risk factors for new infection were identified.