Seroprevalence of Helicobacter pylori infections in Thailand.

Serologic studies in developed countries indicate that Helicobacter (formerly Campylobacter) pylori infection is uncommon until the third decade of life and achieves a peak prevalence of 50% in the seventh decade. In developing countries the epidemiology of H. pylori has not well been described. A sensitive and specific serologic assay for H. pylori infection was validated in Thai patients also studied by culture and histologic examination of biopsy specimens. The prevalence of H. pylori antibodies in persons from a rural Thai community began early (17.5% of children 5-9 years old), increased to 55% during the third decade of life, and peaked (75%) in the 30- to 49-year age group. At a Bangkok orphanage where enteric infections are hyperendemic, 74% of children 1-4 years old were seropositive. This study shows that the prevalence of H. pylori infection in Thailand is higher than in industrialized countries. The high infection rate at the orphanage suggests that person-to-person transmission of H. pylori may be occurring.