Risk Factors for Acquisition of Hepatitis C Virus Infection in Blood Donors: Results of a Case-Control Study

Abstract Background & Aims: Few studies have explored risk factors predicting hepatitis C virus (HCV) infection in blood donors; their results are contradictory. The aim of this study was to evaluate the association between HCV infection and various risk factors in Canadian volunteer blood donors. Methods: Four transfusion centers were involved in this case-control study. A total of 267 confirmed anti–HCV-positive blood donors were interviewed along with 1068 seronegative blood donors matched for sex, age, donation site, and date. Information was collected using a structured telephone interview. The main outcome measures were odds ratios (ORs) and 95% confidence intervals (CIs) for various risk factors from univariate and multivariate analyses using conditional logistic regression. Results: By univariate analysis, 23 variables were associated with anti-HCV positivity. In the final multivariate analysis, only 5 factors remained independently predictive of HCV infection: previous intravenous drug use (OR, 127.5; 95% CI, 26.0–625.0), having lived in a prison or juvenile detention center (56.1; 11.4–275.7), previous blood transfusion (10.5; 4.7–23.2), sexual contact with an intravenous drug user (6.9; 3.1–15.2), and tattooing (5.7; 2.5–13). Conclusions: Most blood donors acquire infection by percutaneous exposure to contaminated blood. A role for sexual transmission is suggested by this study. GASTROENTEROLOGY 1999;116:893-899