Risk factors for hepatitis C virus infection among blood donors in Israel: A case-control study between native Israelis and immigrants from the former Soviet Union

BACKGROUND: The annual hepatitis C virus (HCV) seropositivity prevalence among blood donors (BDs) in Israel is 0.1 percent. Although only 10 percent of the BD population are immigrants from the former Soviet Union (FSUIs), they represent 80 percent of the HCV-seropositive cases. This study aimed to identify HCV risk factors among Native Israeli (NI) and FSUI BDs, to determine if specific interventions are needed. STUDY DESIGN AND METHODS: Two case-control studies were designed, interviewing 178 HCV-positive cases (128 FSUIs, 50 NIs) and 256 HCV-negative controls (128 FSUIs, 128 NIs). All participants were volunteer BDs of Magen David Adom (MDA) Blood Services. RESULTS: A total of 434 BDs of 985 mailed letters consented to be interviewed (44% response rate), without differences in compliance between the study populations. In both, intravenous drug use (IVDU) was the strongest HCV seropositivity-associated risk factor. After IVDU adjustment, important risk factors were age, blood transfusion before 1990, first-time donation, and not practicing teeth cleaning. Close contact with people at risk for HCV (odds ratio [OR], 7.2; 95% confidence interval [CI], 1.9-27.8) and surgery (OR, 7.3; 95% CI, 1.6-34.4) were strong risk factors among NIs, whereas gum surgery (OR, 7.6; 95% CI, 1.1-52.3), hospitalization without surgery (OR, 2.6; 95% CI, 1.1-6.5), and therapy in injection form (OR, 4.9; 95% CI, 2.4-10.2) were merely found among FSUIs, probably resulting from inadequate aseptic conditions. The ORs for age, gum surgery, contact index, and first blood donation differed significantly between the two populations. CONCLUSION: Although the strength of risk factors for HCV differs between Israeli and immigrant BDs, most factors studied did not differ between the groups. Therefore, changes in screening of all BDs are considered.