High prevalence of hepatitis C virus infection in a Southern Italian rural region - Clinical aspects and evidence of inapparent parenteral exposure

Aim. Infection by hepatitis C virus (HCV) generally determines an asymptomatic acute hepatitis which becomes chronic in about 90% of cases. In order to contribute data on the prevalence and the transmission of HCV infection and its associated conditions, anti-HCV seropositivity records in a large sample of a population living in a rural area in Southern Italy were collected and examined. Methods. Data were obtained from the registers of local general practitioners operating in 4 neighbouring countries which make up the region analysed. Information on established or potential risk factors for HCV transmission was obtained by means of a questionnaire. Results. More than half of the entire population of the examined region (19 800 subjects, 60%) had a record for an anti-HCV blood testing. Out of these 19 800 subjects, 2 213 were found to be seropositive, with a resulting overall anti-HCV prevalence higher than that reported for the whole country (11.1% vs 3%). Genotype 1b was the most commonly detected (86%). Anti-HCV prevalence was significantly higher in the 50-59 and 60-69 year age groups than in other age groups. The results of multiple regression analysis showed that blood transfusion, use of glass syringes, surgical interventions, promiscuous use of tooth-brush, promiscuous use of sharp-edged instruments and lowest number of years of schooling were all independent predictors of anti-HCV positive. No association was found with family history of liver disease and alcohol consumption. A total 46.6% of the subjects had chronic hepatitis, 24.4% had cirrhosis, 1.8% had hepatocellular carcinoma and cirrhosis and 27.2% were "asymptomatic" (with normal serum ALT levels and no histological features of chronic hepatitis despite HCV viremia). Conclusion. The most striking result of the study was that the high levels of HCV endemicity was not frequently associated with apparent evidence of parenteral exposure, suggesting that HCV spread in the community can even occur mostly through inapparent parenteral routes.