Objectives: To define the role that sexual transmission plays in the spread of hepatitis C virus (HCV) infection, and to examine the influence of coexistent human immunodeficiency virus (HIV) infection on this mode of transmission.
Design: A multicentre, seroprevalence study of anti-HCV performed in the stable heterosexual partners (SHP) of index cases reactive for anti-HCV.
Setting: Department of Internal Medicine and Section of Gastroenterology of three University Hospitals, Spain.
Subjects: A total of 423 stable heterosexual partners of index cases reactive for anti-HCV. This included a group of 142 intravenous drug users (IVDU), 120 of whom were coinfected with HIV. Additionally, 2886 first-time voluntary blood donors selected at random were included to compare the prevalence of anti-HCV.
Main outcome measures: Serum samples were screened for anti-HCV by a commercially available, second-generation enzyme-linked immunoassay. Tests repeatedly reactive for anti-HCV were analysed by a four-antigen, recombinant immunoblot assay. Anti-HIV was tested by enzyme immunoassay and Western blot was used for confirmation of positive cases.
Results: The prevalence of anti-HCV, was 7.1% in SHP and 1.2% in random donors (P < 0.001). This prevalence was higher in SHP of index cases coinfected with HIV in comparison with that shown in the SHP of index cases only reactive for the anti-HCV (9.1 vs. 6.3%; P = 0.2), particularly when a younger and more homogeneous group such as the SHP of IVDU index cases was considered alone (9.2 vs. 0%; P = 0.1). However, the SHP of IVDU index cases coinfected with HIV were almost three times more likely to be infected with HIV than HCV (24.2 vs. 9.2%).
Conclusions: These data suggest that HCV infection may be sexually transmitted but with low efficiency, and this could be increased in the presence of coexistent HIV infection in the index case.