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The prevalence of anti-HEV was assessed in 2,233 subjects aged 20-79 years in the Republic of San Marino in the years 1990-1991. The sera were tested by ELISA and further confirmed by Western blot (WB) analysis. The overall anti-HEV prevalence was 1.5%. A significant trend by age was observed. Anti-HEV prevalence was 0.6% in subjects <30 years and 3.3% in those older than 70 years of age. Family size larger than four persons (OR = 3.8; 95% CI = 1.8-13.2) was the sole independent predictor of anti-HEV positivity in the multivariate analysis. Anti-HAV and anti-HEV prevalences did not show a parallel trend by age. No association was found either between hepatitis E virus (HEV) or hepatitis C virus (HCV) infections. Follow-up samples 5 years apart were available for 38 out of 54 (70%) anti-HEV ELISA-positive subjects. Eight out of 22 (37%) WB-confirmed anti-HEV-positive subjects were still anti-HEV-positive after 5 years. However, anti-HEV remained positive in all but two (75%) of the subjects with WB-confirmed ELISA positivity value of S/CO > or = 2 (cutoff 1.2), but in only 2 out of the 14 subjects (14%) with a WB-confirmed ELISA positivity value of S/CO < 2 (P < 0.005). None of the 16 subjects ELISA-positive but not WB-confirmed was anti-HEV-positive 5 years apart. Therefore, only a relative proportion of subjects once infected with HEV maintain for at least 5 years anti-HEV antibodies.

Objective: To evaluate the role of faecal-oral transmission in the spread of Helicobacter pylori., Design: A cross-sectional comparison of the patterns of hepatitis A and H. pylori seropositivity., Methods: At interview, blood samples and questionnaire data were collected from a random sample of 1528 healthy subjects aged 20-85 years from the Republic of San Marino. Serum samples from each subject were then tested for anti-H. pylori and anti-hepatitis A antibodies., Results: Overall, 529 of 670 H. pylori-seropositive subjects (78.9%) and 460 of 858 H. pylori-seronegative subjects (53.6%) were hepatitis A seropositive (P<0.01; odds ratio=3.2; confidence interval 95%=2.6-4.1). This association remained after adjustment by a multiple logistic regression analysis for the confounding effect of age and length of schooling, as surrogate for socio-economic status (OR=2.0; CI 95%=1.3-3.3). The age-specific prevalence curves for H. pylori and hepatitis A infections showed a parallel increase by age, although to a lesser extent for H. pylori., Conclusion: These findings provide evidence that in the community studied H. pylori may have spread in a manner similar to that of hepatitis A.

In 1990-1991, the prevalence of antibodies to hepatitis A virus infection (anti-HAV) was assayed by the ELISA method among 1528 apparently healthy subjects, 20-85 years old in the Republic of San Marino. Subjects were selected from the list of residents by a random stratified sampling procedure with a proportional allocation by age, sex and district of residence. The overall anti-HAV prevalence was 64.7%; it increased from 28.6% in subjects 20-30 years old to 97% in those > 60 years (p < 0.01). No gender difference was observed. At the multivariate analysis age > 40 years (OR: 39.5; 95% CI: 12.4-126) and lowest level of schooling (OR: 1.8; 95% CI: 1.1-2.9), which is a good indirect indicator of socio-economic status, resulted both independent predictors of anti-HAV seropositivity. These findings reflect the improved sanitation standards in this area and indicate that the proportion of non-immune adults is increasing with a higher risk of symptomatic infection in the near future.