Epidemiol Infect. 1994 Jun; 112(3): 595-601.

Risk factors for hepatitis C virus infection. A case-control study of blood donors in the Trent Region (UK).

Neal KR, Jones DA, Killey D, James V.

Department of Public Health Medicine, University Hospital, University of Nottingham.

The introduction of screening for hepatitis C virus (HCV) by the National Blood Transfusion Service identified donors who had acquired HCV infection. We undertook a case-control study amongst blood donors in the Trent Region to determine risks for HCV infection. A total of 74 blood donors confirmed positive for hepatitis C infection and 150 age, sex and donor venue matched controls were included in the study. Fifty-three percent of hepatitis C infected blood donors reported previous use of injected drugs compared to no controls; relative risk (RR) not estimatable (lower limit 95% CI = 20). Other risk factors were a history of: receipt of a blood transfusion or blood products RR = 3.6 (95% CI 1.5-8.3), having been a 'health care worker' RR = 2.8 (95% CI 1.1-7.6), tattooing RR = 3.3 (95% CI 1.2-8.7), and an association with having been born abroad RR = 3.2 (95% CI 1.1-9.5). No risk was shown for a history of multiple sexual partners, ear piercing or acupuncture. Injecting drug use explains more than 50% of hepatitis C infections in blood donors, a group who are less likely to have injected drugs than the general population.