Hepatitis C virus reinfection following direct-acting antiviral treatment in the prison setting: the SToP-C study

Background: Injection drug use (IDU) following treatment for hepatitis C virus (HCV) infection may lead to reinfection, particularly if access to harm reduction services is suboptimal. This study assessed HCV reinfection risk following direct-acting antiviral therapy within Australian prisons that had opioid agonist therapy (OAT) programs but did not have needle and syringe programs (NSPs). Methods: The Surveillance and Treatment of Prisoners With Hepatitis C (SToP-C) study enrolled people incarcerated in 4 prisons between 2014 and 2019. Participants treated for HCV were followed every 3-6 months to identify reinfection (confirmed by sequencing). Reinfection incidence and associated factors were evaluated. Results: Among 388 participants receiving treatment, 161 had available posttreatment follow-up and were included in analysis (92% male; median age, 33 years; 67% IDU in prison; median follow-up 9 months). Among those with recent (in the past month) IDU (n = 71), 90% had receptive needle/syringe sharing. During 145 person-years (PY) of follow-up, 18 cases of reinfection were identified. Reinfection incidence was 12.5/100 PY (95% confidence interval [CI]: 7.9-19.8) overall, increasing to 28.7/100 PY (95% CI: 16.3-50.6) among those with recent IDU and needle/syringe sharing. In adjusted analysis, recent IDU with needle/syringe sharing was associated with increased reinfection risk (adjusted hazard ratio [aHR], 4.74 [95% CI: 1.33-16.80]; P = .016) and longer HCV testing interval with decreased risk (ie, chance of detection; aHR, 0.41 per each month increase [95% CI: .26-.64]; P < .001). Conclusions: A high rate of HCV reinfection was observed within prison. Posttreatment surveillance and retreatment are -essential to limit the impact of reinfection. High-coverage OAT and NSPs should be considered within prisons. Clinical Trials Registration: NCT02064049.