Background: Population-based studies of the natural course of chronic viral liver disease that consider comorbidity factors are lacking. Using data from the Dionysos Study, we quantified the burden of chronic viral liver disease and the role of alcohol intake to morbidity and mortality in a representative sample of subjects from the general population of two communities of Northern Italy.
Methods and findings: We followed up 139 subjects with chronic hepatitis C virus (HCV) infection and 61 with chronic hepatitis B virus (HBV) infection for a median (IQR) time of 8.4 (1.0) and 8.3 (0.9) yr, respectively. Ethanol intake was evaluated using a food-frequency questionnaire, fatty liver (FL) was diagnosed by ultrasonography, and liver cirrhosis (LC) and hepatocarcinoma (HCC) were diagnosed by liver biopsy. Exact multivariable Poisson regression was performed to identify predictors of death. The incidence and remission rates of FL were 9.0 and 29.7 in the HCV cohort and 4.0 and 30.4 per 1,000 person-years (PY) in the HBV cohort. Progression to LC and HCC was more common in the HCV than in the HBV cohort (4.5 vs 2.0 and 2.7 vs 2.0 per 1,000 PY, respectively). Ethanol intake was an independent predictor of LC in the HCV cohort [rate ratio (RR) = 4.15 (95% CI 1.02-41.2) for every increase of 30 g/day of ethanol intake at baseline] and of death rate in both cohorts [RR = 8.53 (95% CI 1.40-24.61) and 3.56 (1.34 to 26.50) for every increase of 30 g/day of ethanol intake at baseline].
Conclusions: The morbidity and mortality rate of HBV and HCV infection in the general population is lower than that reported in secondary-care populations, blood donors, or clinical series. Ethanol intake is an independent predictor of LC in subjects with chronic HCV infection and an independent predictor of death in subjects with either HCV or HBV infection.