How to eliminate HCV infection by antiviral treatment

Evaluating the effect of direct-acting antiviral agent treatment scale-up on Hepatitis C virus prevalence among people who inject drugs in UK

BACKGROUND

There is limited empirical work assessing the effectiveness of treatment as prevention (TasP) in reducing HCV prevalence among people who inject drugs (PWID). Here, we used survey data from the UK during 2010-2020, to evaluate the impact of direct-acting antiviral agent (DAA) treatment scale-up, which started in 2015, on HCV prevalence among PWID.

METHODS

We fitted a logistic regression to time/location specific data on prevalence from the Needle Exchange Surveillance Initiative in Scotland and Unlinked Anonymous Monitoring programme in England. For each post-intervention year and location, we quantified the effect of TasP as the difference between estimated prevalence and its counterfactual (prevalence in the absence of scale-up). Progress to elimination was assessed by comparing most recent prevalence against one in 2015.

RESULTS

In 2015, prevalence ranged from 0.44 to 0.71 across the 23 locations (3 Scottish, 20 English). Compared to counterfactuals, there was an absolute reduction of 46% (95% credible interval [32%,59%]) in Tayside in 2020, 35% ([24%,44%]) in Glasgow in 2019, and 25% ([10%,39%]) in the Rest of Scotland in 2020. The English sites with highest estimated absolute reductions in 2021 were South Yorkshire (45%, [29%,58%]), Thames Valley (49%, [34%,59%]) and West London (41%, [14%,59%]). Compared to 2015, there was 80% probability that prevalence had fallen by 65% in Tayside, 53% in Glasgow and 36% in the Rest of Scotland. The English sites with highest % prevalence decrease compared to 2015, achieved with probability 80%, were Chesire & Merseyside (70%), South Yorkshire (65%) and Thames Valley (71%). Higher treatment intensity was associated with higher reductions in prevalence.

CONCLUSION

Conclusion. Real-world evidence showing substantial reductions in chronic HCV associated with increase of HCV treatment scale-up in the community thus supporting the effectiveness of HCV treatmen as prevention in people who inject drugs.

Economic evaluation of the Hepatitis C virus elimination program in the country of Georgia, 2015 to 2017

BACKGROUND AND AIMS

In 2015, the country of Georgia launched an elimination program aiming to reduce the prevalence of Hepatitis C virus (HCV) infection by 90% from 5.4% prevalence (~150 000 people). During the first 2.5 years of the program, 770 832 people were screened, 48 575 were diagnosed with active HCV infection, and 41 483 patients were treated with direct-acting antiviral (DAA)-based regimens, with a >95% cure rate.

METHODS

We modelled the incremental cost-effectiveness ratio (ICER) of HCV screening, diagnosis and treatment between April 2015 and November 2017 compared to no treatment, in terms of cost per quality-adjusted life year (QALY) gained in 2017 US dollars, with a 3% discount rate over 25 years. We compared the ICER to willingness-to-pay (WTP) thresholds of US$4357 (GDP) and US$871 (opportunity cost) per QALY gained.

RESULTS

The average cost of screening, HCV viremia testing, and treatment per patient treated was $386 to the provider, $225 to the patient and $1042 for generic DAAs. At 3% discount, 0.57 QALYs were gained per patient treated. The ICER from the perspective of the provider including generic DAAs was $2285 per QALY gained, which is cost-effective at the $4357 WTP threshold, while if patient costs are included, it is just above the threshold at $4398/QALY. All other scenarios examined in sensitivity analyses remain cost-effective except for assuming a shorter time horizon to the end of 2025 or including the list price DAA cost. Reducing or excluding DAA costs reduced the ICER below the opportunity-cost WTP threshold.

CONCLUSIONS

The Georgian HCV elimination program provides valuable evidence that national programs for scaling up HCV screening and treatment for achieving HCV elimination can be cost-effective.

Excitable models: Projections, targets, and the making of futures without disease

In efforts to control disease, mathematical models and numerical targets play a key role. We take the elimination of a viral infection as a case for exploring mathematical models as 'evidence-making interventions'. Using interviews with mathematical modellers and implementation scientists, and focusing on the emergence of models of 'treatment-as-prevention' in hepatitis C control, we trace how projections detach from their calculative origins as social and policy practices. Drawing on the work of Michel Callon and others, we show that modelled projections of viral elimination circulate as 'qualculations', taking flight via their affects, including as anticipation. Modelled numerical targets do not need 'actual numbers' or precise measurements to perform their authority as evidence of viral elimination or as situated matters-of-concern. Modellers grapple with the ways that their models transform in policy and social practices, apparently beyond reasonable calculus. We highlight how practices of 'holding-on' to projections in relation to imaginaries of 'evidence-based' science entangle with the 'letting-go' of models beyond calculus. We conclude that the 'virtual precision' of models affords them fluid evidence-making potential. We imagine a different mode of modelling science in health, one more attuned to treating projections as qualculative, affective and relational, as excitable matter.

Challenges in Formulation and Implementation of Hepatitis B Elimination Programs

Nearly 257 million individuals have contracted hepatitis B infection around the world. However, only 10% of them know about their illness. Mother to child transmission, nosocomial spread, and sexual transmission are the major etiological factors. Finding the missing millions is a global issue. Hepatitis B care is more difficult compared to hepatitis C as not all patients require treatment and the selection of patients is not straightforward. To eliminate hepatitis B infection, the program should screen pregnant women and start antiviral therapy from the 28th week of pregnancy if hepatitis B virus (HBV) DNA≥ 200,000 IU/mL or hepatitis B e-antigen (HBeAg) reactive. Prevention of perinatal infection, birth dose and neonatal vaccination, post-vaccination monitoring of high-risk groups, catch-up vaccination, and registration of the carriers should be an integral part of the program. Continuum of care is important when planning the elimination program from addressing the risk factors, testing, and referral for treatment. The program should integrate test and treat hepatitis services with existing local health care services. There is a need to create the right environment, raise awareness, remove stigma, and increase screening of those at risk and manage those who require treatment. A national policy should be prepared for capacity building, fund allocation, and implementation strategies. Micro-elimination strategies should boost national elimination effects. Guidelines to diagnose and treat patients with hepatitis B should be simplified. Surveillance should be done to monitor progress, and determine the impact of the elimination program on incidence and mortality, and services.

Hepatitis C Virus Prevalence and Incidence in a Large Nationwide Sample of Patients in Opioid Substitution Treatment in Germany: A Prospective Cohort Study

BACKGROUND

Hepatitis C virus (HCV) infection is highly prevalent among people who inject drugs (PWID). Accurate data on HCV prevalence and incidence rates among patients receiving opioid substitution treatment (OST) are needed to estimate the current and future burden of HCV infections in this high-risk population.

METHODS

Baseline data from routine care were collected between October 2014 and June 2016 from randomly selected OST facilities in Germany. The primary outcome measure was the HCV status (antibody and RNA prevalence). Patients who were HCV antibody-negative at baseline were followed up after 12 months to calculate the HCV incidence rate.

RESULTS

Sixty-three facilities from 14 German Federal States provided clinical data for a total of 2466 OST patients. HCV antibody and HCV RNA prevalence were 58.8% (95% confidence interval [CI], 56.8%-60.8%) and 27.3% (95% CI, 25.5%-29.2%), respectively. At baseline, a total of 528 patients (21.4%) had previously undergone antiviral treatment. Moreover, lower HCV RNA prevalence was associated with female gender, employment, younger age, and shorter duration of OST and opioid dependence. The HCV incidence rate was 2.5 cases per 100 person-years.

CONCLUSIONS

The low HCV RNA prevalence and HCV incidence rates confirm that OST in Germany is an effective setting both for treating chronic HCV infections and for preventing new infections among PWID. Scaling up the provision of OST, HCV testing, and HCV treatment among OST patients are important public health strategies for reducing HCV infections in this high-risk population.

Increased case-finding and uptake of direct-acting antiviral treatment essential for micro-elimination of hepatitis C among people living with HIV: a national record linkage study

OBJECTIVES

Micro-elimination of hepatitis C virus (HCV) in people living with HIV (PLHIV) and co-infected with HCV has been proposed as a key contribution to the overall goal of HCV elimination. While other studies have examined micro-elimination in HIV-treated cohorts, few have considered HCV micro-elimination among those not treated for HIV or at a national level.

METHODS

Through data linkage of national and sentinel surveillance data, we examined the extent of HCV testing, diagnosis and treatment among a cohort of PLHIV in Scotland identified through the national database of HIV-diagnosed individuals, up to the end of 2017.

RESULTS

Of 5018 PLHIV, an estimated 797 (15%) had never been tested for HCV and 70 (9%) of these had undiagnosed chronic HCV. The odds of never having been tested for HCV were the highest in those not on HIV treatment [adjusted odds ratio (aOR) = 7.21, 95% confidence interval (CI): 5.15-10.10). Overall HCV antibody positivity was 11%, and it was at its highest among people who inject drugs (49%). Most of those with chronic HCV (91%) had attended an HCV treatment clinic but only half had been successfully treated (54% for those on HIV treatment, 12% for those not) by the end of 2017. The odds of never having been treated for HCV were the highest in those not on HIV treatment (aOR = 3.60, 95% CI: 1.59-8.15).

CONCLUSIONS

Our data demonstrate that micro-elimination of HCV in PLHIV is achievable but progress will require increased effort to engage and treat those co-infected, including those not being treated for their HIV.

Hepatitis C cascade of care at an integrated community facility for people who inject drugs

OBJECTIVE

To examine the hepatitis C virus (HCV) cascade of care at a community-based integrated harm reduction and treatment facility for people who inject drugs (PWID).

METHODS

Queensland Injectors' Health Network is a community-based agency providing integrated harm reduction and treatment services, including HCV treatment. Program data were analyzed from program commencement (early 2015) up to December 2017.

RESULTS

By December 2017, 476 participants with confirmed HCV infection had enrolled in treatment, of whom 72% had commenced treatment, 65% had completed treatment, and 44% had a confirmed sustained virologic response at 12-weeks post-treatment. Participants who commenced treatment tended to be older (ref 18-34 years; 35-49 years OR = 1.84, p = 0.037, 50+ years OR = 3.19, p = 0.002) and to feel safe and stable in their housing (OR = 2.36, p = 0.021). Participants who completed treatment were less likely to report legal issues (OR = 0.23, p = 0.009).

CONCLUSIONS

Integrated community-based services can successfully engage PWID throughout the HCV treatment journey. Additional social support, including linkage with housing and legal navigation services, may improve treatment uptake and completion. Point-of-care testing, including same-day scripting, could improve treatment uptake.

How to think with models and targets: Hepatitis C elimination as a numbering performance

The field of public health is replete with mathematical models and numerical targets. In the case of disease eliminations, modelled projections and targets play a key role in evidencing elimination futures and in shaping actions in relation to these. Drawing on ideas within science and technology studies, we take hepatitis C elimination as a case for reflecting on how to think with mathematical models and numerical targets as 'performative actors' in evidence-making. We focus specifically on the emergence of 'treatment-as-prevention' as a means to trace the social and material effects that models and targets make, including beyond science. We also focus on how enumerations are made locally in their methods and events of production. We trace the work that models and targets do in relation to three analytical themes: governing; affecting; and enacting. This allows us to situate models and targets as technologies of governance in the constitution of health, which affect and are affected by their material relations, including in relation to matters-of-concern which extend beyond calculus. By emphasising models and targets as enactments, we draw attention to how these devices give life to new enumerated entities, which detach from their calculative origins and take flight in new ways. We make this analysis for two reasons: first, as a call to bring the social and enumeration sciences closer together to speculate on how we might think with models and targets differently and more carefully; and second, to encourage an approach to science which treats evidencing-making interventions, such as models and targets, as performative and political.

Research gaps in viral hepatitis

Introduction

The World Health Organization has aimed for global elimination of both hepatitis B virus (HBV) and hepatitis C virus (HCV) by 2030. Treatments available to cure HCV and control HBV, as well as vaccination to prevent HBV infection, have certainly allowed for such bold goals, yet the final steps to usher in elimination require further evidence.

Discussion

We broadly discuss the needs for three major public health approaches. First, an effective vaccine exists for HBV and mass‐vaccination campaigns have resulted in decreases in hepatitis B surface antigen seroprevalence and overall rates of liver‐related morality. Still, HBV vaccination coverage is poor in certain regions of the world, while the reasons for such low coverage require further study. A prophylactic vaccine is probably needed to eliminate HCV, but is not being readily developed. Second, identifying HBV/HCV infected individuals remains a priority to increase awareness of disease status, particularly for key populations. Research evaluating large‐scale implementation of novel, rapid and mobile point‐of‐care tests would be helpful to determine whether increased awareness is achievable in these settings. Third, antiviral therapy allows for strong HBV suppression and HCV cure, while its access depends on financial factors among many others. Although there is strong evidence to treat key populations and specific groups with progressed disease, as stated in current guidelines, the advantages of extending treatment eligibility to decrease onward spread of HBV/HCV infection and prevent further burden of disease are lacking “real world” evidence. Novel anti‐HBV treatments are being developed to target intrahepatocellular HBV replication, but are still in the early phases of clinical development. Each of the strategies mentioned above has specific implications for HIV infection.

Conclusions

There are certainly effective tools to combat the spread of viral hepatitis and treat infected individuals – yet how they are able to reach key populations, and the infrastructure required to do so, continue to represent the largest research gap when evaluating the progress towards elimination. Continuously adapted and informed research is required to establish the priorities in achieving elimination goals.

Randomized feasibility trial of directly observed versus unobserved hepatitis C treatment with ledipasvir-sofosbuvir among people who inject drugs

AIMS

The advent of direct-acting antivirals for hepatitis C virus (HCV) and limited effectiveness of prevention have generated interest in "Treatment as Prevention" (TasP), in which those most likely to transmit HCV (i.e. people who inject drugs [PWID]) are treated to reduced secondary transmission. However, there are scant data regarding the feasibility of treating PWID at high risk for secondary transmission or the optimal approach to treatment delivery.

METHODS

We conducted a 2:1 randomized trial of modified directly-observed (mDOT) versus unobserved HCV treatment with ledipasvir-sofosbuvir daily for 8 weeks among PWID with 36 weeks of follow-up in San Francisco from 2015-2017. We evaluated recruitment-enrollment, treatment completion, end-of-treatment and 12-week response, and reinfection rate.

RESULTS

Of 83 individuals eligible for screening, 72 (87.6%) attended the screening visit, 33 were eligible, and 31 enrolled; mean age was 42 years, 81% were male, 74% white. All but one participant (in the mDOT arm) completed treatment and 89.4% of mDOT and 96.6% of unobserved arm visits were attended. HCV was undetectable for 96.8% (30/31) at end of treatment and 89.7% (26/29) 12 weeks later (1 relapse, 1 reinfection), with no differences by arm. Two additional reinfections were subsequently identified, for a reinfection rate of 16.3 (95% CI 5.3-50.5) per 100 person-years of observation.

CONCLUSIONS

It was feasible to recruit active PWID for HCV treatment and achieve high retention, viral response, and satisfaction with either mDOT or unobserved protocols, supporting treatment of PWID at risk of transmitting HCV to others. The reinfection rate suggests we successfully reached a high-risk population and that successful HCV TasP initiatives may aim to be sufficient in scope to significantly lower prevalence in the community.

TRIAL REGISTRATION

clinicaltrials.gov NCT02609893.

HCV elimination among people who inject drugs. Modelling pre- and post-WHO elimination era

BACKGROUND

Elimination of hepatitis C virus (HCV) among people who inject drugs (PWID) is a costly investment, so strategies should not only focus on eliminating the disease, but also on preventing disease resurgence. The aims of this study are to compute the minimum necessary antiviral therapies to achieve elimination with and without the additional expansion of harm reduction (HR) programs and to examine the sustainability of HCV elimination after 2030 if treatment is discontinued.

METHOD

We considered two types of epidemic (with low (30%) and high (50%) proportion of PWID who engage in sharing equipment (sharers)) within three baseline chronic HCV (CHC) prevalence settings (30%, 45% and 60%), assuming a baseline HR coverage of 40%. We define sustainable elimination strategies, those that could maintain eliminations results for a decade (2031-2040), in the absence of additional treatment.

RESULTS

The model shows that the optimum elimination strategy is dependent on risk sharing behavior of the examined population. The necessary annual treatment coverage to achieve HCV elimination under 45% baseline CHC prevalence, without the simultaneous expansion of HR programs, ranges between 4.7-5.1%. Similarly, under 60% baseline CHC prevalence the needed treatment coverage varies from 9.0-10.5%. Increasing HR coverage from 40% to 75%, reduces the required treatment coverage by 6.5-9.8% and 11.0-15.0% under 45% or 60% CHC prevalence, respectively. In settings with ≤45% baseline CHC prevalence, expanding HR to 75% could prevent the disease from rebounding after elimination, irrespective of the type of the epidemic. In high chronic HCV prevalence, counseling interventions to reduce sharing are also needed to maintain the HCV incident cases in low levels.

CONCLUSIONS

Harm reduction strategies have a vital role in HCV elimination strategy, as they reduce the required number of treatments to eliminate HCV and they provide sustainability after the elimination. The above underlines that HCV elimination strategies should be built upon the existing HR services, and argue for HR expansion in countries without services.