Seroprevalence and anti-HEV persistence in the general population of the Republic of San Marino

The prevalence of anti-HEV was assessed in 2,233 subjects aged 20-79 years in the Republic of San Marine in the years 1990-1991. The sera were tested by ELISA and further confirmed by Western blot (WB) analysis. The overall a nti-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 m ultivariate analysis. Anti-HAV and anti-HEV prevalences did not show a para llel trend by age. No association was found either between hepatitis E viru s (HEV) or hepatitis C virus (HCV) infections. Follow-up samples 5 years ap art were available for 38 out of 54 (70%) anti-HEV ELISA-positive subjects. Eight out of 22 (37%) WE-confirmed anti-HEV-positive subjects were still a nti-HEV-positive after 5 years. However, anti-HEV remained positive in all but two (75%) of the subjects with WE-confirmed ELISA positivity value of S /CO greater than or equal to 2 (cutoff 1.2), but in only 2 out of the 14 su bjects (14%) with a WE-confirmed ELISA positivity value of S/CO < 2 (P < 0. 005). None of the 16 subjects ELISA-positive but not WE-confirmed was anti- HEV-positive 5 yea rs a pa rt. Therefore, on ly a relative proportion of su bjects once infected with HEV maintain for at least 5 years anti-HEV antibo dies. J. Med, Virol. 58:49-53, 1999. (C) 1999 Wiley-Liss, Inc.