HELICOBACTER ANTIBODIES IN 1973 AND 1994 IN THE ADULT-POPULATION OF VAMMALA, FINLAND

Changes in Helicobacter pylori seroprevalence were studied determining IgG and IgA antibodies of 408 randomly selected adults aged 15-74 yea rs living in Vammala, Finland in 1973 and of 504 similarly selected su bjects in 1994. Seroprevalence increased by age at both time points. T he age-adjusted seroprevalence rate was clearly lower in 1994 than in 1973 (31 vs. 56%, P = 0.001). Paired serum samples of 224 subjects col lected in 1973 and 1994 showed that the antibody status remained unalt ered in 92%; 4% seroconverted and 4% seroreverted within the 21 years. The decrease in the seroprevalence rate in the population and the per sistence of individual antibody status over two decades support a diff erence in H. pylori infection rates among birth cohorts over time rath er than continuous acquisition of new infections with advancing age. T hus the risk of helicobacter infection in Vammala, Finland has been hi ghest in childhood and continuously decreased at least for the last fi ve decades.