Between 2014 and 2019, the SToP-C trial observed a halving in HCV incidence in four Australian prisons following scale-up of direct-acting antiviral (DAA) therapy. However, the contribution of HCV treatment to this decline is unclear because the study did not have a control group. We used modeling to consider this question.
Approach and Results
We parameterized and calibrated a dynamic model of HCV transmission in prisons to data from each SToP-C prison on incarceration dynamics, injecting drug use, HCV prevalence trends among prison entrants, baseline HCV incidence before treatment scale-up, and subsequent HCV treatment scale-up. The model projected the decrease in HCV incidence resulting from increases in HCV treatment and other effects. We assessed whether the model agreed better with observed reductions in HCV incidence overall and by prison if we included HCV treatment scale-up, and its prevention benefits, or did not. The model estimated how much of the observed decrease in HCV incidence was attributable to HCV treatment in prison. The model projected a decrease in HCV incidence of 48.5% (95% uncertainty interval [UI], 41.9-54.1) following treatment scale-up across the four prisons, agreeing with the observed HCV incidence decrease (47.6%; 95% CI, 23.4-64.2) from the SToP-C trial. Without any in-prison HCV treatment, the model indicated that incidence would have decreased by 7.2% (95% UI, −0.3 to 13.6). This suggests that 85.1% (95% UI, 72.6-100.6) of the observed halving in incidence was from HCV treatment scale-up, with the remainder from observed decreases in HCV prevalence among prison entrants (14.9%; 95% UI, −0.6 to 27.4).
Our results demonstrate the prevention benefits of scaling up HCV treatment in prison settings. Prison-based DAA scale-up should be an important component of HCV elimination strategies.
Bibliographical noteFunding Information:
Supported by Australian National Health and Medical Research Council Partnership Project Grant (1092547), Gilead Sciences, and the UK National Institute for Health Research (NIHR). The funder of the study had no role in study design, data collection, data analysis, data interpretation, or writing of the report. The corresponding author had full access to all the data in the study and had final responsibility for the decision to submit for publication.
The SToP‐C study was funded by an Australian National Health and Medical Research Council (NHMRC) Partnership Project Grant (1092547), including support from Gilead Sciences. A.G.L., J.S., and P.V. acknowledge support from the NIHR Health Protection Research Unit in Behavioural Science and Evaluation at the University of Bristol. P.V. also acknowledges support from the NIHR‐funded EPIToPe project and the NIHR HTA project (NIHR128513). J.G. is supported by an NHMRC Investigator Grant (1176131). N.K.M. is supported by NIAID and NIDA (R01AI147490) and the University of San Diego Center for AIDS Research (CFAR), an NIH‐funded program (P30 AI036214). J.G., G.J.D., and A.R.L. were supported by Fellowships from NHMRC (Nos. 1176131, 1118864, and 1137587). This work was carried out using the computational facilities of the Advanced Computing Research Centre, University of Bristol ( http://www.bristol.ac.uk/acrc/) . The Kirby Institute is funded by the Australian Government Department of Health and Ageing. The SToP‐C study is a partnership project involving the Kirby Institute, Justice Health & Forensic Mental Health Network, Corrective Services NSW, NSW Ministry of Health, NSW Users and AIDS Association, Hepatitis NSW, and Gilead Sciences. The SToP‐C study group includes members of the Protocol Steering Committee; Coordinating Centre, The Kirby Institute, UNSW Sydney; and Study Site Coordinators. The views expressed in this publication are those of the authors and do not necessarily represent the position of the Australian Government or Gilead Sciences. We also acknowledge the contributions of members of the SToP‐C Study Group: Stuart Loveday (Chair, Hepatitis NSW); Gregory Dore, Andrew Lloyd, Jason Grebely, Tony Butler, Georgina Chambers, Carla Treloar, and Marianne Byrne (UNSW Sydney); Roy Donnelly, Colette McGrath, Julia Bowman, Lee Trevethan, and Katerina Lagios (Justice Health & Forensic Mental Health Network); Luke Grant and Terry Murrell (Corrective Services NSW); Nicky Bath, Victor Tawil, Annabelle Stevens, and Libby Topp (NSW Health); Alison Churchill and Kate Pinnock (Community Restorative Centre); Natasha Martin (University of California San Diego); Steven Drew (Hepatitis NSW); and Mary Harrod (NSW Users and AIDS Association). Gregory Dore, Andrew Lloyd, Behzad Hajarizadeh, Tony Butler, Pip Marks, Mahshid Tamaddoni, Stephanie Obeid, Gerard Estivill Mercade, Maria Martinez, and Marianne Byrne. William Rawlinson, Malinna Yeang, Matthew Wynn, and Christiana Willenborg. Angela Smith, Ronella Williams, Brigid Cooper, Kelly Somes, Carina Burns, Camilla Lobo, Karen Conroy, Luke McCredie, Carolyn Café, and Jodie Anlezark. Protocol Steering Committee: Coordinating Centre (The Kirby Institute, UNSW Sydney): Laboratory Services (NSW Health Pathology): Site Research Coordinators:
Potential conflict of interest: Dr. Martin received grants from Gilead and Merck. Dr. Grebely is on the speakers’ bureau for and received grants from AbbVie, Cepheid, Gilead, and Merck. He received grants from Hologic. Dr. Dore received grants from Gilead and AbbVie. Dr. Lloyd advises for and received grants from Gilead. He received grants from AbbVie.
© 2021 The Authors. Hepatology published by Wiley Periodicals LLC on behalf of American Association for the Study of Liver Diseases.
- hepatitis C virus
- direct-acting antiviral treatment
- people who inject drugs
- injecting drug use
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