National trends in retreatment of HCV due to reinfection or treatment failure in Australia

Retreatment of Hepatitis C Virus Among People Who Inject Drugs

BACKGROUND

Hepatitis C virus (HCV) is a leading cause of infectious disease death in the United States. Although highly effective direct-acting antiviral (DAA) regimens are well established, retreatment among people who inject drugs (PWID) has not been sufficiently studied. This study assessed DAA retreatment outcomes and associated factors.

METHODS

We performed analyses of longitudinal data from the HERO Study, a US-based multi-site pragmatic randomized trial conducted in 8 states to evaluate effectiveness of 2 HCV care models among DAA treatment-naïve PWID in opioid treatment programs and community clinics. After initial HERO Study sofosbuvir/velpatasvir (SOF/VEL) treatment, participants eligible for retreatment were identified, from 15 September 2016 to 13 September 2021. This analysis characterizes participants who either did not achieve sustained virologic response (SVR) or were reinfected with HCV post-SVR. We compared categorical variables using Fisher exact test and continuous variables using the Welch 2 sample t test for means and an asymptotic 2-sample Mood median test.

RESULTS

One hundred four participants were identified as eligible for retreatment. Less than half, 43 (41.3%), initiated retreatment. Among the 25 who initiated retreatment and for whom SVR results were available, 24 achieved SVR (96%). Participants who did not achieve SVR initiated retreatment more promptly than participants reinfected post-SVR (respectively, 471 vs 784 days on average, P < .001).

CONCLUSIONS

After reinfection or not achieving SVR with the first DAA regimen, retreated PWID achieved higher SVR rates than with initial DAA treatment. To attain HCV elimination and benefit individual and public health, assisting PWID with accessing prompt retreatment is crucial.

Hepatitis C (HCV) Reinfection and Risk Factors among Clients of a Low-Threshold Primary Healthcare Service for People Who Inject Drugs in Sydney, Australia

Hepatitis C (HCV) reinfection studies have not focused on primary healthcare services in Australia, where priority populations including people who inject drugs (PWID) typically engage in healthcare. We aimed to describe the incidence of HCV reinfection and associated risk factors in a cohort of people most at risk of reinfection in a real-world community setting. We conducted a secondary analysis of routinely collected HCV testing and treatment data from treatment episodes initiated with direct-acting antiviral (DAA) therapy between October 2015 and June 2021. The overall proportion of clients (N = 413) reinfected was 9% (N = 37), and the overall incidence rate of HCV reinfection was 9.5/100PY (95% CI: 6.3-14.3). Reinfection incidence rates varied by sub-group and were highest for Aboriginal and/or Torres Strait Islander people (20.4/100PY; 95% CI: 12.1-34.4). Among PWID (N= 321), only Aboriginality was significantly associated with reinfection (AOR: 2.73, 95% CI: 1.33-5.60, p = 0.006). High rates of HCV reinfection in populations with multiple vulnerabilities and continued drug use, especially among Aboriginal and Torres Strait Islander people, highlight the need for ongoing regular HCV testing and retreatment in order to achieve HCV elimination. A priority is resourcing testing and treatment for Aboriginal and/or Torres Strait Islander people. Our findings support the need for novel and holistic healthcare strategies for PWID and the upscaling of Indigenous cultural approaches and interventions.

The time of cure: hepatitis C treatment and the matter of reinfection among people who inject drugs

Australia has made considerable progress towards the public-health 'elimination' of the hepatitis C virus. Nonetheless, reinfection remains a key challenge, with little understanding regarding the lived complexities of post-cure life among people who inject drugs. Our analysis examines reinfection through the lens of 'time', a largely overlooked and under-utilised analytical concept within the field of hepatitis C. Drawing on qualitative data from a study examining treatment outcomes and reinfection, our analysis concentrates on three participant accounts or 'cases'. Working within a new materialist framework, we combine recent social science scholarship which, firstly, posits cure as a socio-material 'gathering', and secondly, proposes a 'futurology' of hepatitis C and its treatment. We found participant accounts troubled the neat binary of pre- and post-treatment life, instead detailing the challenges of remaining virologically safe while navigating complex, local life-worlds. Rather than a singular, post-treatment future instantiated by cure, participants described the fluid, emergent nature of what we might describe as 'lived' or 'embodied' time, including multiplicities of becoming in a perpetual present. We conclude that our understanding of reinfection needs to move beyond its current, narrow biomedical conception and organising temporal logic to honour and incorporate complexity in practice.

Acute hepatitis C virus infection: clinical update and remaining challenges

Acute hepatitis C virus (HCV) infection is a global health concern with substantial geographical variation in the incidence rate. People who have received unsafe medical procedures, used injection drugs, and lived with human immunodeficiency virus are reported to be most susceptible to acute HCV infection. The diagnosis of acute HCV infection is particularly challenging in immunocompromised, reinfected, and superinfected patients due to difficulty in detecting anti-HCV antibody seroconversion and HCV ribonucleic acid from a previously negative antibody response. With an excellent treatment effect on chronic HCV infection, recently, clinical trials investigating the benefit of direct-acting antivirals (DAAs) treatment for acute HCV infection have been conducted. Based on the results of cost-effectiveness analysis, DAAs should be initiated early in acute HCV infection prior to spontaneous viral clearance. Compared to the standard 8-12 week-course of DAAs for chronic HCV infection, DAAs treatment duration may be shortened to 6-8 weeks in acute HCV infection without compromising the efficacy. Standard DAA regimens provide comparable efficacy in treating HCV-reinfected patients and DAA-naïve ones. For cases contracting acute HCV infection from HCV-viremic liver transplant, a 12-week course of pangenotypic DAAs is suggested. While for cases contracting acute HCV infection from HCV-viremic non-liver solid organ transplants, a short course of prophylactic or pre-emptive DAAs is suggested. Currently, prophylactic HCV vaccines are unavailable. In addition to treatment scale-up for acute HCV infection, practice of universal precaution, harm reduction, safe sex, and vigilant surveillance after viral clearance remain critical in reducing HCV transmission.