RESUMO
The prevalence of and risk factors for HCV and HBV infections in the general population and the predictive value of ALT screening in identifying anti-HCV positive subjects have been evaluated in a small Sicilian town. A random 1:4 sampling from the census of the general population was performed. Anti-HCV, HCV-RNA, HCV genotype, HBsAg, and anti-HBc were tested. The linkage between HCV infection and potential risk factors was evaluated by multiple logistic regression analysis. Among 721 subjects studied, 75 (10.4%) were anti-HCV positive. The HCV infection rate increased from 0.4% in subjects 10-29 years of age to 34% in those > 60 years of age. Among the 75 anti-HCV positive subjects, 66.7% were HCV-RNA positive and 36% had abnormal ALT, in contrast abnormal ALT levels were found in 4.3% of the 646 anti-HCV negative subjects (P < 0.01). HCV genotype 1b infected the majority (88.0%) of viremic subjects. Exposure to HBV infection (anti-HBc positivity) was found in 11.2% of subjects; HBsAg positivity was 0.7%. At multivariate analysis, two variables were associated with HCV infection: age > or = 45 years (OR 27.8; CI 95% = 11.0-70.2) and previous hospitalization (OR 2.5; CI 95% = 1.3-4.7). ALT testing had low positive predictive value (PPV = 49.1%) for HCV infection. The positive predictive value was good (88%) in people > or = 60 years of age, but minimal (16.7%) in those below 60. These findings indicate that HCV infection is common in the elderly, perhaps as a result of past iatrogenic transmission. The present low rate of HCV infection among the younger generations coupled with the low progression of the viral related liver damage does not support the projection of a future increasing incidence in the next decades of the burden of HCV-related chronic disease. HBV infection, formerly common in this area, is already in sharp decline. In an area of high HCV endemicity, screening of the general population by ALT cannot be used a surrogate marker to detect HCV infection in those susceptible to treatment.