Abstract
Helicobacter pylori is associated with the pathogenesis of chronic gastritis, peptic ulcer disease and gastric cancer (Matysiak-Budnik & Megraud, 2006). It is thought that the acquisition of H. pylori infection occurs mainly during childhood (Sherman, 2004). Although an intrafamilial route has been suggested (Kivi & Tindberg, 2006), the major routes of transmission of H. pylori are poorly understood. There have been cases reported in which the intrafamilial route does not appear to apply. In 2002, we investigated H. pylori prevalence in 224 children (age range 0–6 years) in three districts in Miyagi prefecture, Japan (Fujimura et al., 2004). The H. pylori prevalence rate in the children studied was 0 % in district C. H. pylori prevalence rates in districts A and B were approximately equal to those in other reports from Japan (Kato et al., 2003a). However, there were no reports of 0 % prevalence rates such as found in district C. Therefore, we examined H. pylori prevalence 3 years later to determine whether the prevalence rate in the children of district C had changed.
From among the 51 children (age 3–5 years) investigated in district C in 2002, 40 children (age 6–8 years in the follow-up study) in 37 households, from whom informed consent was obtained, were re-examined in this study. H. pylori status was estimated using a stool antigen test (Premier Platinum HpSA; Meridian Bioscience) (Kato et al., 2003b). According to the manufacturer's instructions, the results were divided into three groups for H. pylori infection: positive (OD450/630 0.120); negative (<0.100); and indeterminate (0.100–0.199). Further, we studied H. pylori prevalence among the family members (the parents and siblings) who live together with the subject children. Informed consent was obtained from 24 of the 37 original households (64.9 %). However, because agreement for obtaining stool samples was not obtained, the H. pylori status of the parents and siblings was assessed using a commercial ELISA kit (URINELISA H. pylori antibody; Otsuka Pharmaceutical) to detect anti-H. pylori IgG antibodies (Miwa et al., 1999).
The survey collected information regarding childcare and the living environment and included birthplace, feeding methods in infancy and the source of the household water.