Risk factor exposure among hepatitis C virus RNA positive Swedish blood donors--the role of parenteral and sexual transmission.

The potential modes of transmission for hepatitis C virus (HCV) infections were studied using a multivariate analysis of risk factor exposure among 51 2nd generation anti-HCV and HCV-RNA positive and matched anti-HCV negative blood donors. The following variables were found to be independently associated with anti-HCV and HCV-RNA positivity: intravenous drug use (IVDU) (p < 0.001), blood transfusion (p < 0.01), tattoos (p < 0.001), previous hospitalization (p < 0.05), history of sexually transmitted disease (STD) (p < 0.001) and lack of travels outside of Europe (p < 0.05). Among the 23 HCV-RNA positive donors without a history of IVDU or blood transfusion, an increased frequency of hospitalization (p = 0.017) and history of STD (p = 0.023) were found. Five of 22 sexual partners of the 51 index blood donors were HCV-RNA positive and in one of these couples sexual transmission was suspected. Anti-HCV and HCV-RNA positive donors were more often seropositive for herpes simplex virus type 2 (HSV-2) antibodies than were HCV-negative controls (p = 0.015). Sexual transmission of HCV may occur, but the possible role of HSV-2 requires further investigation.