Sexually transmitted hepatitis C virus superinfection in HIV/hepatitis C virus co-infected men who have sex with men.

We report two cases of sexually transmitted hepatitis C virus (HCV) superinfection in HIV/HCV-co-infected patients with high-risk sexual behaviour. The two patients had chronic HCV and a history of sexually transmitted infections. HCV superinfection was confirmed by phylogenetic analysis. No risk factors for HCV were found except unprotected anal sex with multiple casual male partners. HCV serology and serum HCV RNA should be examined periodically in HIV-infected men who have sex with men engaging in high-risk sexual behaviours.