title: The need for treatment scale-up to impact HCV transmission in people who inject drugs in Montréal, Canada: a modelling study.
abstract: HCV transmission remains high in people who inject drugs (PWID) in Montréal. New direct-acting antivirals (DAAs), highly effective and more tolerable than previous regimens, make a "Treatment as Prevention" (TasP) strategy more feasible. This study assesses how improvements in the cascade of care could impact hepatitis C burden among PWID in Montréal.
  
  
  
  We used a dynamic model to simulate HCV incidence and prevalence after 10 years, and cirrhosis complications after 10 and 40 years. Eight scenarios of improved cascade of care were examined.
  
  
  
  Using a baseline incidence and prevalence of 22.1/100 person-years (PY) and 53.1%, implementing the current cascade of care using DAAs would lead to HCV incidence and prevalence estimates at 10 years of 9.4/100PY and 55.8%, respectively. Increasing the treatment initiation rate from 5%/year initially to 20%/year resulted in large decreases in incidence (6.4/100PY), prevalence (36.6%), and cirrhosis complications (-18%/-37% after 10/40 years). When restricting treatment to fibrosis level ≥ F2 instead of F0 (reference scenario), such decreases in HCV occurrence were unreachable. Improving the whole cascade of care led to the greatest effect by halving both the incidence and prevalence at 10 years, and the number of cirrhosis complications after 40 years.
  
  
  
  The current level of treatment access in Montréal is limiting a massive decrease in hepatitis C burden among PWID. A substantial treatment scale-up, regardless of fibrosis level, is necessary. While improving the rest of the cascade of care is necessary to optimize a TasP strategy and control the HCV epidemic, a treatment scale-up is first needed.
authors.affiliation: IAME, UMR 1137, INSERM, F-75018, Paris, France.|IAME, UMR 1137, Univ Paris Diderot, Sorbonne Paris Cité, F-75018, Paris, France.|Direction régionale de santé publique du Centre intégré universitaire de santé et de services sociaux du Centre-Sud-de-l'Ile-de-Montréal, 1301 rue Sherbrooke est, Montréal, QC, H2L 1M3, Canada.
authors.forename: Anthony
authors.initials: A
authors.lastname: Cousien
authors.affiliation: Direction régionale de santé publique du Centre intégré universitaire de santé et de services sociaux du Centre-Sud-de-l'Ile-de-Montréal, 1301 rue Sherbrooke est, Montréal, QC, H2L 1M3, Canada.
authors.forename: Pascale
authors.initials: P
authors.lastname: Leclerc
authors.affiliation: Direction régionale de santé publique du Centre intégré universitaire de santé et de services sociaux du Centre-Sud-de-l'Ile-de-Montréal, 1301 rue Sherbrooke est, Montréal, QC, H2L 1M3, Canada.
authors.forename: Carole
authors.initials: C
authors.lastname: Morissette
authors.affiliation: Centre de recherche, Centre hospitalier de l'Université de Montréal (CRCHUM), 900 Saint-Denis, Montréal, QC, H2X 0A9, Canada.
authors.forename: Julie
authors.initials: J
authors.lastname: Bruneau
authors.affiliation: Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Campus Longueuil, 150 place Charles-Le Moyne, Longueuil, QC, J4K 0A8, Canada.
authors.forename: Élise
authors.initials: É
authors.lastname: Roy
authors.affiliation: Laboratoire Paul Painlevé UMR CNRS 8524, UFR de Mathématiques, Université des Sciences et Technologies Lille 1, Cité Scientifique, Villeneuve d'Ascq, France.
authors.forename: Viet Chi
authors.initials: VC
authors.lastname: Tran
authors.affiliation: IAME, UMR 1137, INSERM, F-75018, Paris, France.|IAME, UMR 1137, Univ Paris Diderot, Sorbonne Paris Cité, F-75018, Paris, France.|Service des Maladies Infectieuses et Tropicales, Hôpital Bichat Claude Bernard, Paris, France.
authors.forename: Yazdan
authors.initials: Y
authors.lastname: Yazdanpanah
authors.affiliation: Direction régionale de santé publique du Centre intégré universitaire de santé et de services sociaux du Centre-Sud-de-l'Ile-de-Montréal, 1301 rue Sherbrooke est, Montréal, QC, H2L 1M3, Canada. joseph.cox@mcgill.ca.|Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Purvis Hall, 1020 Pine Avenue West, Montreal, QC, H3A 1A3, Canada. joseph.cox@mcgill.ca.|Chronic Viral Illness Service, McGill University Health Centre, 1001 Decarie Blvd., Montreal, QC, H4A3J1, Canada. joseph.cox@mcgill.ca.
authors.forename: Joseph
authors.initials: J
authors.lastname: Cox
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000998:Antiviral Agents / Q000627:therapeutic use*; D017281:Cost of Illness; D005260:Female; D006297:Health Services Accessibility / Q000706:statistics & numerical data*; D006526:Hepatitis C / Q000188:drug therapy / Q000453:epidemiology / Q000517:prevention & control / Q000635:transmission*; D006801:Humans; D015994:Incidence; D008103:Liver Cirrhosis / Q000150:complications / Q000821:virology; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D015995:Prevalence; D011792:Quebec / Q000453:epidemiology; D015819:Substance Abuse, Intravenous / Q000821:virology*; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000998:Antiviral Agents
keywords: Cascade of care; Direct-acting antiviral; Dynamic model; HCV elimination; People who inject drugs; Treatment initiation criteria