Background:A cross-sectional investigation was carried out between 2000 and 2002 to assess the prevalence of hepatitis C virus infection (HCV) in Naples, southern Italy.Patients and Methods:Five groups of individuals were investigated, two at low risk and three at high risk for HCV infection. Blood sample sera were collected among 5,391 individuals (4,059 men and 1,332 women): 1,972 general practitioner (GP) patients and 781 employees of the National Cancer Institute (NCI) of Naples (low-risk groups); 524 male prisoners, 1,436 intravenous drug users (IDUs) and 678 hemodialysis patients (high-risk groups).Results:Overall HCV seropositivity rates ranged from 6.4% among employees of the NCI to 37.4% among male prisoners …