HETEROSEXUAL TRANSMISSION OF HEPATITIS-C VIRUS AND THE POSSIBLE ROLE OF COEXISTENT HUMAN-IMMUNODEFICIENCY-VIRUS INFECTION IN THE INDEX CASE- A MULTICENTER STUDY OF 423 PAIRINGS

Objectives. To define the role that sexual transmission plays in the s pread of hepatitis C virus (HCV) infection, and to examine the influen ce of coexistent human immunodeficiency virus (HIV) infection on this mode of transmission. Design. A multicentre, seroprevalence study of a nti-HCV performed in the stable heterosexual partners (SHP) of index c ases reactive for anti-HCV. Setting. Department of Internal Medicine a nd Section of Gastroenterology of three University Hospitals, Spain. S ubjects. A total of 423 stable heterosexual partners of index cases re active for anti-HCV. This included a group of 142 intravenous drug use rs (IVDU), 120 of whom were coinfected with HIV. Additionally, 2886 fi rst-time voluntary blood donors selected at random were included to co mpare the prevalence of anti-HCV. Main outcome measures. Serum samples were screened for anti-HCV by a commercially available, second-genera tion enzyme-linked immunoassay. Tests repeatedly reactive for anti-HCV were analysed by a four-antigen, recombinant immunoblot assay. Anti-H IV was tested by enzyme immunoassay and Western blot was used for conf irmation 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 th at 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 H IV were almost three times more likely to be infected with HIV than HC V (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 ca se.