A comparison of risk factors for HCV-mono-infection, HIV-mono-infection, and HCV/HIV-co-infection in a community setting.

The prevalence of HIV infection in HCV patients is much lower than the prevalence of HCV infection in HIV patients. Whereas the higher prevalence of HCV infection in HIV is clearly related to drug abuse, the reasons for the lower prevalence of HIV infection in HCV patients has not been reported. The prevalence of non-sexual and sexual risk factors associated with acquisition of hepatitis C and HIV were studied in HIV-mono-infected, HCV-mono-infected, and HCV/HIV-co-infected individuals. None of the 114 HCV-mono-infected patients tested positive for HIV and this finding was associated with a significantly lower number of men who have sex with men (MSM) among the HCV-mono-infected subjects than among either the HIV-mono-infected or HCV/HIV-co-infected individuals. Unprotected anal intercourse and sex for money or drugs were reported less often by HCV-mono-infected individuals than by HIV-mono-infected and HCV/HIV-co-infected subjects. Having sex with an intravenous-drug user (IVDU) was reported more frequently by both HCV-mono-infected and HCV/HIV-co-infected individuals than by HIV-mono-infected individuals. Sub-analysis of the group of MSM revealed that IVDU differentiated between HIV-mono-infected and HCV/HIV-co-infected subjects. These results reveal that the lower prevalence of HIV in HCV patients is related to a lower number of MSM in this group and that sex with an IVDU is a surrogate marker for drug abuse related to acquiring HCV but not HIV. The guidelines should include strategies for testing for HCV and HIV in patients with these infections.