Background: There are widely discrepant findings on the sexual transmission of hepatitis C virus (HCV), commonly transmitted by the parenteral route. Coinfection with HCV is common in subjects infected with HIV.
Goal: This case-control study evaluated the prevalence of anti-HCV in subjects with hetero- or homosexual contact and no history of intravenous drug abuse or blood transfusion, according to the presence or absence of HIV infection.
Study design: In this case-control study, the cases considered were 106 consecutive patients who showed positive anti-HIV test results. For each case, two control subjects were selected who had been screened for HIV infection at the authors' center and found to have anti-HIV-negative test results, and who matched the case in terms age (+/- 5 years), gender, and risk factor for parenterally transmitted infections.
Results: The prevalence of subjects with positive test results for hepatitis B surface antigen (HBsAg) was similar between cases and control subjects (4.7% versus 2.4%). Positivity for anti-hepatitis B core antigen in connection with negative test results for HBsAg was observed more frequently in the 106 cases than in the 212 control subjects (33.9% versus 15.6%; P = 0.0003). Anti-HCV positivity was more frequent in the cases than in the control subjects (15.1% versus 5.2%; P = 0.005). In particular, among subjects who had hetero- or homosexual intercourse with a steady partner who had positive anti-HIV test results, anti-HCV positivity was observed in 18.7% of the 32 cases and 1.6% of the 64 control subjects (P = 0.008).
Conclusion: This study demonstrated that in subjects who had only a sexual risk factor for parenterally transmitted infections, HIV may enhance the sexual transmission of HCV.