Background: Helicobacter pylori is an important gastric pathogen usually acquired in childhood. The presumed lifelong progression of H. pylori infection has recently been called into question in some longitudinal studies on children. In this follow-up study the prevalence and persistence of H. pylori antibodies in Finnish children and adolescents from three communities was determined.
Methods: We measured H. pylori antibodies in follow-up serum samples of 337 Finnish children who participated in a measles-mumps-rubella vaccine study started in 1982. All available samples collected in 1983, 1987 and 1995 were studied first; additional serum samples collected yearly were studied from children who became seropositive during the follow-up period.
Results: The overall prevalence of H. pylori antibodies was 5.6%. About two-thirds of the Helicobacter infections were acquired before the age of 7 years; of the remaining one-third the time of seroconversion varied between 7 and 19 years. No seroreverters were found. There were no statistically significant differences in the seroprevalence of H. pylori antibodies in the three communities studied.
Conclusions: The prevalence of H. pylori antibodies in Finnish children studied was low. Although the majority of new infections were found in children younger than 7 years of age, new Helicobacter infections were acquired throughout childhood and adolescence. Once acquired H. pylori infection, as verified by Helicobacter antibodies, persisted.