Risk factors for hepatitis C virus infection in blood donors: a case‐control study

Abstract

OBJECTIVE: To investigate risk factors for hepatitis C virus (HCV) infection in Sydney blood donors. DESIGN: Blood donors confirmed to be positive for HCV antibodies were compared with blood donors with a positive result of a screening assay, but whose HCV antibody status had not been confirmed. A questionnaire on sexual, parenteral and other potential risk factors was administered to both groups. SETTING: Blood Transfusion Service in Sydney. PARTICIPANTS: The study enrolled 220 donors who had confirmed HCV infection, and 210 donors who did not. RESULTS: The relative risk associated with injecting drug use was 63 (95% confidence interval, 19-260) when comparison was made with all other donors. Among donors who did not report injecting drug use, a significant, independent increase in risk was found in association with having had a tattoo. Among donors who did not give a history of parenteral exposure, there was a significantly greater risk in people with more than one life-time sexual partner than in those with at most one partner. CONCLUSION: A history of injecting drug use was elicited as the most important risk factor in Sydney blood donors with antibodies to hepatitis C. Having had a tattoo, and an increased number of lifetime sexual partners were also independently associated with HCV infection.