The SToP-C study
A hepatitis C treatment as prevention (TasP) approach was evaluated in the Surveillance and Treatment of Prisoners with hepatitis C (SToP-C) study which was conducted in four prisons in New South Wales (NSW), Australia between 2014 and 2019.
The factors contributing to the rationale for the study included:
- Community wide scale-up of antiviral therapy for HIV was shown in some studies in Africa to reduce incidence (Brault 2019).
- A high prevalence of chronic hepatitis C infection in the NSW prisons, which was estimated to be above 20% of all prisoners at the time of protocol development (JH&FMHN, Network Patient Health Survey 2015).
- A high incidence of hepatitis C transmission in the NSW prisons, which was estimated to be above 10% per annum amongst those who reported injecting drug use at some time in their life (Cunningham, 2017).
- Each injecting/sharing event in the NSW prisons was estimated to carry a one in 200 chance of transmitting hepatitis C (Boelen, 2014).
- Limited evidence of effectiveness of existing harm reduction measures against hepatitis C transmissions in the NSW prisons, which included widespread distribution of a quaternary amine disinfectant to cleanse injecting devices, and moderate coverage of opioid agonist therapy (OAT) of approximately 50 recipients per 100 people who inject drugs (PWID) whilst incarcerated (Bretana, 2020).
- Government-funded DAA treatment became widely available in the prisons in March 2016, with an estimated 10% of all prisoners with chronic hepatitis C infection being treated in that year (Papaluca, 2019).
Against this backdrop, the SToP-C study involved ensuring that the majority of individuals in the prisoner population in the selected centres were tested for hepatitis C, and those found to be infected promptly treated with DAA therapy and cured in order to prevent new transmissions.
The study was commenced in late 2014 with funding from the Australian National Health and Medical Research Council (NHMRC) and Gilead Sciences Pty Ltd, in partnership with the Justice Health and Forensic Mental Health Network (JH&FMHN), Corrective Services NSW, and key consumer organisations.
The study was conducted over five years in four prisons in NSW, Australia, with the primary objective of demonstrating the effectiveness of rapid scale-up of testing and DAA treatment in reducing hepatitis C incidence (i.e. TasP).
“The advantage of hepatitis C treatment in the context of treatment-as-prevention is that, while trying to achieve population-level control of an infectious disease and its spread, you’re providing individual benefit… it’s amazing.”
The study initially enrolled prisoners aged 18 years or older with adequate English and mental health status to consent, complete interviews regarding risk behaviour, and provide blood samples.
These participants were followed up at six monthly intervals in the Surveillance phase over the first two to three years of the study to resolve the prevalence of hepatitis C antibody and viraemia with referral of those found to be chronically infected to the existing Hepatitis Service. Scale-up of DAA therapy, supported by SToP-C, was introduced in the Treatment scale-up phase to maximise access to treatment for all those found to be infected or re-infected, with ongoing surveillance for all participants until study closure.
Study results (Hajarizadeh 2021)
There were 3691 individuals enrolled in the study. These participants represented a coverage of approximately 60% of all prisoners who spent one month or more in one of the four correctional centers over the five year study period.
At enrolment, there were 719 individuals with hepatitis C RNA detected (19%), leaving 2,965 who were at-risk of primary hepatitis C infection (n=2,240 who were hepatitis C antibody negative) or hepatitis C reinfection (n=725 who were HCV antibody positive but HCV RNA negative).
Among the at-risk population with longitudinal follow-up (n=1,643; median age 33 years; 82% male), 31% reported injecting drug use in prison. In the Surveillance phase, 39/416 (9%) eligible participants received DAA treatment through the Hepatitis Service, whereas during the Treatment scale-up period DAA treatment was initiated in 349/499 (70%) of eligible participants.
The hepatitis C incidence declined by 48%, from 8.31 to 4.35 per 100 person-years between Surveillance and Treatment scale-up periods. The incidence of primary infection declined from 6.64 to 2.85 per 100 person-years (incident rate ratio -IRR: 0.43, 95%CI: 0.25, 0.74), while the incidence of re-infection declined from 12.36 to 7.27 per 100 person-years (IRR: 0.59, 95%CI: 0.35-1.00). Adjusted analysis indicated a 50% reduction in the risk of HCV transmission between Surveillance and Treatment scale-up periods (adjusted Hazard Ratio: 0.50, 95% CI: 0.33, 0.76).
These findings indicate that DAA treatment scale-up was associated with a reduced hepatitis C incidence in the prisons, indicative of hepatitis C treatment-as-prevention (TasP). The findings support broad DAA treatment scale-up among incarcerated populations. The findings also suggest improved harm reduction remains a priority to minimise re-infection.
An evaluation of the cost-effectiveness of the SToP-C intervention is underway.
Hepatitis C Incidence before and following DAA treatment scale-up in SToP-C. The red solid line represents the trend in HCV incidence observed during the Surveillance phase and then in the Treatment scale-up phase. The red dashed line represents the predicted incidence if the effect of treatment scale-up is removed.
Development of this toolkit
Over the five years of the SToP-C study, numerous implementation challenges in scaling up testing and treatment were faced and resolved.
An Implementation Committee met regularly over the course of the study to advise on, and contribute to, the development of the SToP-C toolkit (the Toolkit).
Four methods were used to inform the Toolkit:
- An Issues Register was established at study commencement in which barriers were identified, and the ways in which these barriers were resolved were systematically gathered in real time from a variety of stakeholders including sub-committee members, health and custodial management, and staff working in the correctional centres.
- A qualitative study was conducted with interviews of: prisoners living with or without current HCV infection before Treatment scale-up, prisoners treated for HCV infection during the Treatment scale-up period, families of prisoners, correctional officers and senior administrators, correctional health staff, policy makers at local and state levels, and consumer advocates. These interviews covered several relevant topics including prevention programs, and the acceptability of DAA treatment scale-up for prevention (Rance 2021).
- A review of policy frameworks across Australian prison jurisdictions was conducted in order to identify the organisational policies and procedures that impact on the implementation of DAA treatment scale-up. This review was intended to inform recommendations on how to frame service delivery to policymakers in scenarios both of strong policy support as well as a weak policy environment (Lafferty 2018).
- Mathematical modeling was undertaken to understand the epidemiological impact of HCV treatment as prevention in the prison setting, the implications for the custodial and health workforce and other infrastructure implications, and health economic analyses of the impact of HCV treatment-as-prevention in the prison setting and on the wider community.
This Toolkit provides insights into these lessons learnt in SToP-C to assist policy makers anproviders in the custodial and health sectors to undertake similar prison-based scale-up of testing and direct-acting antiviral (DAA) therapy, including to achieve TasP in the prison setting.