Epidemiology of hepatitis C virus infection in an area of Southern Italy.

BACKGROUND/AIMS: Hepatitis C virus (HCV) has been recognized as a major cause of liver disease, but little is known about its diffusion at population level. To estimate the prevalence and incidence of HCV infection and to explore potential risk factors at population level, an epidemiologic study was carried out. METHODS: A cohort was built up in 1985, on a random sample of the population of Castellana, a small town in southern Italy (Bari province), and followed up until 1993. HCV ELISA II and RIBA HCV 2.0 were used as screening and confirmatory tests, respectively. RESULTS: The overall anti-HCV prevalence was 26.0% (511/1969) at enrollment. The HCV infection incidence rate was 34.2x100,000 person-years (3 cases/8766 persons-years). A secular trend (referent born before 1930; born 1930-39 Odds Ratio (OR) 0.72, 95% Confidence Interval (95% CI) 0.56-0.94; born 1940-49, OR 0.33, 95% CI 0.25-0.44; born 1950 or after, OR 0.15, 95% CI 0.09-0.23) and geographical pattern (referent born outside Bari province; born in Bari province, OR 1.71, 95% CI 0.93-3.16; born in Castellana G, OR 2.29, 95% CI 1.29-4.05) were found by logistic regression analysis after controlling for several confounding factors. CONCLUSIONS: The high prevalence, moderate incidence, and marked decrease in HCV infection in the cohort of birth in a population without known risk factors suggest that an epidemiological transition has been operating at population level since the 1950's