Epidemiology of Helicobacter pylori infection in children: A serologic study of the Kyushu region in Japan

Background: The prevalence of Helicobacter pylori infection in children var ies as a function of socioeconomic development, with low rates in developed countries and high rates in developing countries. The prevalence of H. pyl ori infection in Japanese children is unknown. Methods: The present study examined the effect of living conditions on the prevalence of H. pylori infection in children. We determined the prevalence of H. pylori infection in healthy children of the Kyushu region in Japan a nd compared it with the prevalence in institutionalized children with sever e neurologic illness. Serum concentrations of anti-H. pylori IgG antibody w ere measured by an enzyme-linked immunosorbent assay in 336 healthy childre n and 56 patients with severe neurologic impairment. An antibody concentrat ion > 50 units/mL was taken as evidence of infection. Results: The prevalence of H. pylori seropositivity in healthy children inc reased with age (P <0.0001) and was 29% in children 15-19 years of age. Thi s value is slightly higher than prevalences reported in developed countries (5-15%), but is lower than in developing countries (30-60%). Seropositivit y did not vary with respect to gender, water supply or location of housing. Helicobacter pylori seropositivity was more prevalent among institutionali zed children aged 5-19 years than their healthy counterparts (P <0.005). Conclusions: The intermediate prevalence of H. pylori seropositivity in hea lthy children between that measured in developed and developing countries i s consistent with the socioeconomic 'westernization' of Japan.