title: HCV epidemiology in high-risk groups and the risk of reinfection.
abstract: Injecting risk behaviours among people who inject drugs (PWID) and high-risk sexual practices among men who have sex with men (MSM) are important routes of hepatitis C virus (HCV) transmission. Current direct-acting antiviral treatment offers unique opportunities for reductions in HCV-related liver disease burden and epidemic control in high-risk groups, but these prospects could be counteracted by HCV reinfection due to on-going risk behaviours after successful treatment. Based on existing data from small and heterogeneous studies of interferon-based treatment, the incidence of reinfection after sustained virological response range from 2-6/100 person years among PWID to 10-15/100 person years among human immunodeficiency virus-infected MSM. These differences mainly reflect heterogeneity in study populations with regards to risk behaviours, but also reflect variations in study designs and applied virological methods. Increasing levels of reinfection are to be expected as we enter the interferon-free treatment era. Individual- and population-level efforts to address and prevent reinfection should therefore be undertaken when providing HCV care for people with on-going risk behaviour. Constructive strategies include acknowledgement, education and counselling, harm reduction optimization, scaled-up treatment including treatment of injecting networks, post-treatment screening, and rapid retreatment of reinfections.
authors.affiliation: Department of Infectious Diseases, Akershus University Hospital, Lørenskog, Norway; Institute for Clinical Medicine, University of Oslo, Norway; Department of Gastroenterology, Oslo University Hospital, Norway. Electronic address: havardmi@medisin.uio.no.
authors.forename: Håvard
authors.initials: H
authors.lastname: Midgard
authors.affiliation: School of Health and Life Sciences, Glasgow Caledonian University, United Kingdom; NHS National Services Scotland, Health Protection Scotland, Glasgow, United Kingdom.
authors.forename: Amanda
authors.initials: A
authors.lastname: Weir
authors.affiliation: School of Health and Life Sciences, Glasgow Caledonian University, United Kingdom; NHS National Services Scotland, Health Protection Scotland, Glasgow, United Kingdom.
authors.forename: Norah
authors.initials: N
authors.lastname: Palmateer
authors.affiliation: Division of Infectious Diseases, Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine, University of Pennsylvania, United States.
authors.forename: Vincent
authors.initials: V
authors.lastname: Lo Re
authors.affiliation: Unidad de Enfermedades Infecciosas y Microbiología, Hospital Universitario de Valme, Sevilla, Spain.
authors.forename: Juan A
authors.initials: JA
authors.lastname: Pineda
authors.affiliation: Unidad de Enfermedades Infecciosas y Microbiología, Hospital Universitario de Valme, Sevilla, Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: Macías
authors.affiliation: Department of Infectious Diseases, Akershus University Hospital, Lørenskog, Norway; Institute for Clinical Medicine, University of Oslo, Norway.
authors.forename: Olav
authors.initials: O
authors.lastname: Dalgard
mesh_terms: D000998:Antiviral Agents / Q000627:therapeutic use; D005260:Female; D040261:Harm Reduction; D006526:Hepatitis C / Q000150:complications / Q000453:epidemiology* / Q000635:transmission; D018451:Homosexuality, Male; D006801:Humans; D015994:Incidence; D008297:Male; D015995:Prevalence; D012008:Recurrence; D012307:Risk Factors; D012309:Risk-Taking; D012725:Sexual Behavior; D015819:Substance Abuse, Intravenous / Q000150:complications
chemical_list: D000998:Antiviral Agents
keywords: Epidemiology; HCV; Injecting drug use; MSM; PWID; Reinfection; Risk behaviours