In the United States, incident hepatitis C among men who have sex with men has been ongoing since at least 1984. Risk factors included unprotected receptive anal intercourse with multiple partners, HIV infection, and lower CD4 T-cell count among HIV-infected men.
Background Prospective characterization of hepatitis C virus (HCV) transmission in both human immunodeficiency virus (HIV)–infected and –uninfected men who have sex with men (MSM) over the entire HIV epidemic has not been comprehensively conducted.
Methods To determine the trends in and risk factors associated with incident HCV in MSM since 1984, 5310 HCV antibody (anti-HCV)–negative MSM in the Multicenter AIDS Cohort Study were prospectively followed during 1984–2011 for anti-HCV seroconversion.
Results During 55 343 person-years (PYs) of follow-up, there were 115 incident HCV infections (incidence rate, 2.08/1000 PYs) scattered throughout the study period. In a multivariable analysis with time-varying covariates, older age (incidence rate ratio [IRR], 1.40/10 years, P < .001), enrollment in the later (2001–2003) recruitment period (IRR, 3.80, P = .001), HIV infection (IRR, 5.98, P < .001), drinking >13 alcoholic drinks per week (IRR, 1.68, P < .001), hepatitis B surface antigen positivity (IRR, 1.68, P < .001), syphilis (IRR, 2.95, P < .001), and unprotected receptive anal intercourse with >1 male partner (IRR, 3.37, P < .001) were independently associated with incident HCV. Among HIV-infected subjects, every 100 cell/mm3 increase in CD4 count was associated with a 7% (P = .002) decrease in the HCV incidence rate up to a CD4 count of 500 cells/mm3, whereas there was no association with highly active antiretroviral therapy.
Conclusions The spread of HCV among both HIV-infected and -uninfected MSM in the United States has been ongoing since the beginning of the HIV epidemic. In HIV-infected men with <500 CD4+ T cells, the HCV incidence rate was inversely proportional to CD4 T-cell count.