Evidence from a nine-year birth cohort study in Japan of transmission pathways of Helicobacter pylori infection

We examined the longitudinal changes of Helicobacter pylori infection withi n 46 families with children and 48 couples without children living in Japan . The study cohort was monitored from 1986 to 1994. H. pylori status was as sessed by the presence of anti-H. pylori immunoglobulin G antibodies. At st udy entry, H. pylori prevalence in children with positive mothers was 23% v ersus 5% in children with negative mothers (odds ratio = 5.3; 95% confidenc e interval = 0.6 to 42.8). Seroconversion (rate of 1.5%/year) was evident o nly among children Living with positive mothers and did not differ among ad ults living with or without children. These data strongly support the clust er phenomenon of H. pylori infection among families, the key role of the in fected mothers in the transmission within families, and the importance of a dult-child transmission and not vice versa.