Theme: Epidemiology & Public Health Research Year: 2017
Background: Little is known about HCV epidemics among men who have sex with men (MSM) in the United States. We assessed HCV primary and reinfection incidence among HIV+ MSM in San Diego in relation to injecting drug and methamphetamine use.
Methods: We performed a retrospective cohort analysis of HCV primary incidence among HIV+ MSM attending the largest HIV clinic in San Diego from 2000-2015. Primary incident HCV infection was assessed among HIV+ MSM with a baseline negative anti-HCV test between 2000 and 2015, and defined as any new positive anti-HCV or HCV-RNA test after the start of follow-up. HCV reinfection was assessed among a subset of HIV+ MSM successfully treated for HCV between 2008-2015.
Results: A total of 2,395 MSM, who were initially HCV uninfected and had at least 1 further test during a median of 4.4 years of follow-up (IQR 1.9-8.1), were included in the incidence analysis. Overall, 149 HCV seroconversions occurred over 12,573 person-years(py) of follow-up, leading to an incidence of 1.19/100py (95%CI 1.00-1.39). Incidence significantly increased over time, from 0.36/100py in 2000-2003 rising to 1.52/100py in 2012-2015 (p=0.003). Incidence was three-fold higher among HIV+ MSM reporting ever methamphetamine use only compared to those with no history of meth or IDU use (1.44/100py vs 0.48/100py, p<.001) with a significant increase over time(p=0.001). Compared to those with no history of meth or IDU use, HCV incidence was also significantly(p=0.001) higher among HIV+ MSM reporting a history of IDU only(6.3/100py), or combined IDU and meth use (2.3/100py). Among patients with successful HCV therapy, the observed HCV reinfection rate was 2.89/100py(95%CI 0.60-8.44). Conclusions: HCV incidence is high and increasing among HIV+ MSM in San Diego, with reinfection rates 2-3 fold higher than primary infection among HIV+ MSM. Further work determining epidemic trajectory and prevention required to control the epidemic is needed.
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