Intravenous drug abuse--the major route of hepatitis C virus transmission among alcohol-dependent individuals?

As the prevalence of hepatitis C virus (HCV) antibodies has been reported to be high among alcohol-dependent individuals, we screened prospectively 310 consecutive non-selected alcoholic outpatients for HCV and possible routes of transmission. Using a second-generation enzyme-linked immunosorbent assay test and retesting all positive sera with a second-generation recombinant immunoblot assay, we found the prevalence of anti-HCV to be 14.5% (45 of 310). Of the 45 anti-HCV-positive individuals, 39 (88.7%) had a history of intravenous drug abuse, 2 had received blood transfusions, and only 4 lacked an identifiable source of infection. The magnitude of alcohol consumption, number of hospital admissions, duration of alcohol dependence, or presence of tattooing could not be shown to be factors of importance for the transmission of HCV infection. Our results suggest that a history of intravenous drug abuse is a common phenomenon and the predominant route of HCV transmission among alcoholics. True community-acquired infection would appear to be rare.