Abstract
In 1990, to study regional prevalences and risk factors of Helicobacter pylori infection in healthy young adult males, sera were collected from a nationwide sample of 1659 males (mean age 20.7 years) at introduction into the Air Force School for military students in Caserta, Italy. An enzyme-linked immunosorbent assay was used to detect H. pylori specific immunoglobulin G antibodies. The observed overall seropositivity rate was 17.5% (95% CI 15.7-19.4). Prevalence was higher in southern Italy and in the Italian islands as compared with northern Italy and central Italy (21.3% vs. 9.5%). Multiple logistic regression analysis showed that residence in southern areas and islands was the strongest predictor of the likelihood of H. pylori seropositivity; number of siblings in the household was marginally associated; years of father's schooling was not a significant predictor. H. pylori positive subjects were more likely positive for antibodies to hepatitis A virus infection (anti-HAV) than those H. pylori negative (35.4% vs. 24.9%; Odds Ratio 1.7, 95% CI 1.3-2.2). Adjustment for the confounding effect of sociodemographic variables weakened this association (OR 1.3, 95% CI 1.0-1.7). These findings suggest that differences in environmental conditions rather than in socioeconomic status may have played the major role in the different spread of H. pylori infection across the country.