Heterosexual transmission of hepatitis C virus and the possible role of coexistent human immunodeficiency virus infection in the index case. A multicentre study of 423 pairings.

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.