Sexually transmitted hepatitis C virus infections: current trends, and recent advances in understanding the spread in men who have sex with men

Abstract

Introduction Hepatitis C virus (HCV) is a major public health threat. Although the recent availability of highly effective directly acting antivirals created optimism towards HCV elimination, there is ongoing transmission of HCV in men who have sex with men (MSM). We here report current epidemiological trends and synthesise evidence on behavioural, network, cellular and molecular host factors associated with sexual transmission of HCV, in particular the role of HIV‐1 co‐infection. We discuss prevention opportunities focusing on the potential of HCV treatment. Methods We searched MEDLINE, fact sheets from health professional bodies and conference abstracts using appropriate keywords to identify and select relevant reports. Results and discussion Recent studies strongly suggest that HCV is transmitted via sexual contact in HIV‐positive MSM and more recently in HIV‐negative MSM eligible for or on pre‐exposure prophylaxis. The reinfection risk following clearance is about 10 times the risk of primary infection. International connectedness of MSM transmission networks might contribute to ongoing reinfection. Some of these networks might overlap with networks of people who inject drugs. Although, the precise mechanisms facilitating sexual transmission remain unclear, damage to the mucosal barrier in the rectum could increase susceptibility. Mucosal dendritic cell subsets could increase HCV susceptibility by retaining HCV and transmitting the virus to other cells, allowing egress into blood and liver. Early identification of new HCV infections is important to prevent onward transmission, but early diagnosis of acute HCV infection and prompt treatment is hampered by the slow rate of HCV antibody seroconversion, which in rare cases may take more than a year. Novel tests such as testing for HCV core antigen might facilitate early diagnosis. Conclusions High‐risk sexual behaviour, network characteristics, co‐infection with sexually transmitted infections like HIV‐1 and other concomitant bacterial and viral sexually transmitted infections are important factors that lead to HCV spread. Targeted and combined prevention efforts including effective behavioural interventions and scale‐up of HCV testing and treatment are required to halt HCV transmission in MSM.

Hepatitis C Guidance 2019 Update: American Association for the Study of Liver Diseases–Infectious Diseases Society of America Recommendations for Testing, Managing, and Treating Hepatitis C Virus Infection

“…Because use of allografts from HCV‐viremic donors in HCV‐negative recipients is a recent development in transplant medicine, there are no data on possible long‐term hepatic and extrahepatic adverse effects associated with HCV exposure, even among those cured of the infection. Allograft recipients who are HCV viremic can potentially sexually transmit the virus to their partner(s), particularly among MSM …”

“…Allograft recipients who are HCV viremic can potentially sexually transmit the virus to their partner(s), particularly among MSM. (74,(367)(368)(369)(370)(371)(372) The HCV guidance panel recommends that all programs performing HCV viremia discordant solid organ transplantations have a strategy to execute and document a rigorous informed consent process; assure access to HCV treatment and retreatment, as needed; and ensure long-term follow-up of organ recipients to monitor for potential late consequences of HCV exposure and allograft function.…”

Syndecan 4 Upregulation on Activated Langerhans Cells Counteracts Langerin Restriction to Facilitate Hepatitis C Virus Transmission

“…Interestingly, under normal conditions LCs are refractory to HCV but upon HIV-1 infection or when activated LCs are able to retain HCV, facilitating transmission to target cells (19). These data suggest that activation of LCs in MSM might allow the virus to penetrate mucosal tissues and establish dissemination via the blood or lymph (24). Thus, the activation state of the LCs dictates HCV susceptibility but the molecular mechanism deciding the fate of the virus are unknown.…”

HIV and sexually transmitted infections: reconciling estranged bedfellows in the U = U and PrEP era

“…de Vries discusses the challenges that clinicians face in addressing STI in the current treatment-as-prevention era [17]. The topic of emerging infectious diseases is discussed by Nijmeijer and colleagues, focusing primarily on Hepatitis C but also discussing the potential of other agents that are not often thought of as being sexually transmitted to emerge when behavioural patterns change [19]. The topic of emerging infectious diseases is discussed by Nijmeijer and colleagues, focusing primarily on Hepatitis C but also discussing the potential of other agents that are not often thought of as being sexually transmitted to emerge when behavioural patterns change [19].…”

“…Rojas Castro and colleagues discuss the patterns of STI that have been seen in individuals who use biomedical HIV prevention, that is, PrEP, and address the question of risk compensation versus risk maintenance when individuals who are at high risk for HIV/STI utilize interventions that can protect them against HIV but not STI [18]. The topic of emerging infectious diseases is discussed by Nijmeijer and colleagues, focusing primarily on Hepatitis C but also discussing the potential of other agents that are not often thought of as being sexually transmitted to emerge when behavioural patterns change [19]. Rietmeijer discusses the evolution of STI clinics in recent years, and their continued need to change in order to optimally co-manage HIV and STI [20].…”