Seroconversion of Helicobacter pylori in Korean male employees

Helicobacter pylori infections are acquired primarily during childhood, but also occur in adults. As no published estimates are available on the seroconversion rate of H. pylori in the Korean population, the purpose of this study was to evaluate the incidence and prevalence of H. pylori infection in male Korean employees.

Levels of anti-H. pylori IgG were measured by ELISA, and gastroscopic findings were checked in 588 employees of the Subway Corporation (aged 40-60 years, male) in 1997, 1998, 1999, 2000, and 2003. Questionnaire responses concerning socio-economic state, education level, and type of job were analyzed versus serologic test results.

Out of the 588 subjects, 455 (77.4%) were positive for anti-H. pylori IgG. Multivariate analysis showed that abnormal gastroscopic findings, especially duodenal ulcers, were more frequent in the H. pylori-positive group (17.6) than in the initially H. pylori-negative group (9.0%) (OR: 1.71, 95% CI: 1.07-2.81). Among the multiple questionnaires, only the proportion of white-collar workers was significant; that is, it was lower in the H. pylori-positive group (44/6) than in the initial H. pylori-negative group (57.9%) (OR: 0.62, 95% CI: 0.41-0.92). Seventeen of 133 subjects (12.8%) who were initially seronegative underwent seroconversion during a 6-year follow-up period, a seroconversion rate of 2.13%/annum.

The seroprevalence of H. pylori infection in this study group was 77.4% and duodenal ulcer was more frequent in H. pylori-positive subjects, thus confirming the relationship between H. pylori infection and duodenal ulcer. Seroconversion of H. pylori infection in the Korean male employees was determined to be 2.13% per year, suggesting that new infections occur continuously even during late adulthood.