Risk factors for hepatitis C virus infection among blood donors in an HIV-epidemic area in Thailand.

OBJECTIVE The role of sexual transmission in hepatitis C virus (HCV) infection has not yet been completely elucidated. This study aimed to compare the risk factors for HCV and human immunodeficiency virus (HIV) infection in an HIV epidemic area of Thailand where HIV is mainly transmitted heterosexually. DESIGN AND SUBJECTS Sera from 3053 blood donors were collected and tested for HCV and HIV between January and March 1994. Altogether 1756 (57.5%) of the donors were interviewed about demographics and several risk factors. RESULTS The prevalence rates of HIV and HCV infections determined by antibody assays were 2.3% and 2.2%, respectively. Sexual risk factors were clearly shown among anti-HIV positive donors. These clear associations were not found, however, among anti-HCV positive donors. In contrast, previous histories of injecting drug use and being tattooed were found in some anti-HCV positive donors but less frequently in anti-HIV positive donors. CONCLUSIONS Sexual transmission may play a relatively minor role in HCV transmission compared with HIV, in this area.