Despite advances in antiviral treatments, the study reveals that traditional prevention strategies have not curbed reinfection rates among men who have sex with men linked to specific high-risk behaviors.
Daniel S Fierer, MD practices infectious diseases , specializing in HIV and HCV infections.
Image credits: Mount Sinai
Over nearly two decades, a study conducted in New York City (NYC) has revealed high rates of Hepatitis C virus (HCV) reinfection among men who have sex with men (MSM) and have HIV. Published in Clinical Infectious Diseases, research by Daniel S Fierer, MD, Professor of Medicine (Infectious Diseases) at the Icahn School of Medicine at Mount Sinai underscores that sexual transmission of HCV is far from uncommon or inefficient in this population. Despite the availability of direct-acting antiviral treatments, the study found these alone are insufficient to eliminate HCV among MSM in NYC.
Between 2000 and 2018, a cohort of 304 MSM with HIV, who had previously cleared HCV, experienced 42 reinfections across 898 person-years, resulting in an incidence rate of 4.7 per 100 person-years. Analysis of 1245 post-clearance visits revealed that only rectal receipt of semen was significantly associated with reinfection (hazard ratio: 9.7, 95% confidence interval: 3.3–28.3, P < .001); methamphetamine use did not show a significant association.
In his exclusive interview with Contagion Fierer explains, "The population we studied differs significantly from the general MSM with HIV population in terms of HCV prevalence within their sexual networks." This suggests certain sexual networks within NYC may harbor much higher rates of HCV than previously understood.
A prospective cohort study in NYC on MSM with HIV who had cleared HCV aimed to determine the incidence and risk factors associated with HCV reinfection. Risk behaviors such as rectal receipt of semen and sexualized methamphetamine use, including route of administration, were assessed. Multivariable analysis utilized the Andersen-Gill extension of the Cox proportional hazards model.
“Our study design was to measure all reinfections, rather than just first reinfections, as that obviously misses data that would presumably be relevant to understanding the problem,” Fierer clarifies. “Most prospective risk factor studies, in the HCV and other fields too, evaluate only the first occurrence of a subsequent event, which is why you probably have not seen reference to Andersen-Gill before–for instance, the risk factors for recurrence of lung cancer, or perhaps the risk factor for breaking a hip,” he continues, “So there is really nothing special about it– it is just a Cox model, which is the standard for evaluating time-dependent variables, with a modification that allows all events to be analyzed and not forcing discarding of events after the initial one.”
The study acknowledges limitations, including its single institution and single-city scope within a large country. Although, the cohort encompassed the practices of more than 50 healthcare providers serving individuals with HIV across all boroughs of NYC, a city that houses 7% of MSM with HIV in the US. The cohort had a slightly lower representation of Black and Hispanic individuals compared to the overall population of MSM with HIV who had primary HCV, as reported by the NYC Department of Health. The cohort was more diverse than other reinfection cohorts.
According to Fierer, “Condom use, the most effective currently available intervention to prevent semen ejaculation into the rectum, has not been successful as an HCV prevention strategy. Our results therefore suggest the need for novel interventions to prevent sexual transmission of HCV among MSM.”
An international study in 2023 published in The Journal of Infectious Diseases found a connection between injection drug use and HCV reinfection. Although, their analysis only considered one variable at a time. Similarly, our initial analysis suggested a link between methamphetamine use and reinfection, but our more comprehensive analysis did not confirm this. Fierer demonstrated that the MSM with HIV in our study, who had already cleared HCV, differed significantly from the general MSM with HIV population, particularly in terms of HCV prevalence. The study inferred that the sexual networks of individuals monitored for reinfection likely had a much higher prevalence of HCV compared to the general population.2
Fierer concludes “This is brand new, that our results have, I think for the first time, described the actual problem; and then we need to do what will likely be multiple studies to figure out how to approach the problem.It turns out that this situation has parallels in HIV, and this is a line of study that I have found fascinating in that field, but, with >30K ongoing HIV transmissions yearly, we clearly have not solved that yet either,”
In summary, this study sheds new light on the challenges of preventing HCV reinfection among MSM in urban settings like NYC. It emphasizes the urgency of developing innovative strategies to combat the ongoing epidemic of sexually transmitted HCV.
