Hepatitis E virus infection in north-east Italy: serological study in the open population and groups at risk.

Developed western countries are considered to be relatively free from endemic foci of hepatitis E virus (HEV) infections. The aim of this study was to assess the seroepidemiology of HEV in north-east Italy. Of the 2361 individuals studied 1889 were representative of the general population and 472 were from groups at high risk for viral infections: 279 drug users and 193 patients on chronic haemodialysis. All sera were tested for hepatitis C virus antibody (HCVAb), human immunodeficiency virus antibody (HIVAb) and for hepatitis B virus (HBV) serology. Two solid-phase enzyme-linked immunosorbent assays (ELISA) were used to study the seroepidemiology of HEV IgG, the first (using recombinant antigens) for confirmation of initially reactive samples. The prevalence of circulating hepatitis E virus antibody (HEVAb) was 2.6% in the open population, 5.4% among drug users and 9.3% among patients on chronic haemodialysis. In the open population a positive relationship between age and prevalence of HEVAb was observed. A relationship between presence of HEVAb and serological evidence of previous HBV or HCV infections was also observed in this study. It was concluded that HEV infections are present in north-east Italy and are more frequent among subjects at risk for blood-borne viral infections. The positive correlation, observed in the open population, between age and prevalence of HEVAb suggests the presence of a cohort effect.