[Incidence of anti-HCV positivity in a Sicilian population with liver diseases].

The discovery of virus C as an etiological agent of chronic liver disease (CLD) has modified previously-held concepts concerning the etiology of this disease. In a study of 581 consecutive patients with CLD, we confirmed that virus C was the sole agent responsible for it in 64.2% of all cases. Moreover, virus C was characteristically associated with virus B, alcohol consumption, and autoimmunity. When the various CLD were separated into subgroups, i.e., chronic persistent hepatitis (CPH), chronic active hepatitis (CAH), and liver cirrhosis (LC), virus C continued to be the main etiological agent, varying from 60.5% to 68.3%: this suggested constant evolution from milder to more severe forms of liver disease. Virus B alone was found less frequently, probably thanks to the virtual elimination of post-transfusion hepatitis B and the anti-B virus vaccination which is now widely administered. Frequency was 15.2% in the CPH group but lower in the LC and CAH groups (7.4% and 6.3% respectively), suggesting that evolution from the milder to the more severe forms of liver disease may not occur. Finally, we confirmed a statistically significant difference in mean age between hepatitis C virus positive men and women (p < 0.0001): in men, frequency was higher in the 20- to 50-year-old group; in women it was higher in the 50+year-old group.