Defining populations and injecting parameters among people who inject drugs: Implications for the assessment of hepatitis C treatment programs

Validation of case-ascertainment algorithms using health administrative data to identify people who inject drugs in Ontario, Canada

OBJECTIVES

Health administrative data can be used to improve the health of people who inject drugs by informing public health surveillance and program planning, monitoring, and evaluation. However, methodological gaps in the use of these data persist due to challenges in accurately identifying injection drug use (IDU) at the population level. In this study, we validated case-ascertainment algorithms for identifying people who inject drugs using health administrative data in Ontario, Canada.

STUDY DESIGN AND SETTING

Data from cohorts of people with recent (past 12 months) IDU, including those participating in community-based research studies or seeking drug treatment, were linked to health administrative data in Ontario from 1992 to 2020. We assessed the validity of algorithms to identify IDU over varying look-back periods (ie, all years of data [1992 onwards] or within the past 1-5 years), including inpatient and outpatient physician billing claims for drug use, emergency department (ED) visits or hospitalizations for drug use or injection-related infections, and opioid agonist treatment (OAT).

RESULTS

Algorithms were validated using data from 15,241 people with recent IDU (918 in community cohorts and 14,323 seeking drug treatment). An algorithm consisting of ≥1 physician visit, ED visit, or hospitalization for drug use, or OAT record could effectively identify IDU history (91.6% sensitivity and 94.2% specificity) and recent IDU (using 3-year look back: 80.4% sensitivity, 99% specificity) among community cohorts. Algorithms were generally more sensitive among people who inject drugs seeking drug treatment.

CONCLUSION

Validated algorithms using health administrative data performed well in identifying people who inject drugs. Despite their high sensitivity and specificity, the positive predictive value of these algorithms will vary depending on the underlying prevalence of IDU in the population in which they are applied.

Hepatitis C virus micro-elimination in people who inject drugs: Challenges and chance in Taiwan and worldwide

With the introduction of direct-acting antivirals, elimination of hepatitis C virus (HCV) infection is becoming possible. People who inject drugs (PWID) represent a population with a high risk for HCV infection, which has been reported as high as 90% in Taiwanese PWID. To reach the goal of HCV elimination, PWID is a key population deserving special attention. Barriers in HCV care cascade still exist in PWID, and interventions to promote access to HCV diagnosis, link-to-care, treatment, and prevention for PWID are warranted. Although HCV micro-elimination can be achieved in some prisons and opioid substitution therapy (OST) centers by a multidisciplinary team and integrated care in Taiwan, there are still several unmet needs for HCV elimination in PWID. Continuous efforts, such as the participation of OST specialists and the continuum of care for HCV among PWID, are needed to achieve HCV elimination in Taiwan. In addition, the combination of harm reduction services, treatment as prevention and regular posttreatment HCV surveillance is critical to substantially reduce HCV transmission and prevalence in PWID.

Pilot Outreach Program in Remedis-The Promising Step toward HCV Elimination among People Who Inject Drugs

The global effort to eliminate HCV infection requires new approaches to accessing and testing the affected population in a setting with as low of a threshold as possible. The focus should be on socially marginalized people who inject drugs (PWIDs) and who are not willing or able to visit standard medical services. With this vision, we established an outreach service-a testing point in an ambulance in the park in front of the Main Railway Station of the capital city of Prague-to provide bloodborne disease testing and treatment. The service was available every week on Wednesday afternoon. Over the initial two years of our experience, 168 unique people were tested. Of them, 82 (49%) were diagnosed with chronic HCV infection and were eligible for treatment with antivirals. Of these, 24 (29%) initiated antiviral treatment over the study period, and 17 (71%) of these individuals achieved a documented sustained virological response. Offering medical services in PWIDs' neighborhoods helps overcome barriers and increase the chances that they will become patients and begin HCV treatment. The described outcomes appear promising for reaching the vision of linkage to the care of such a hard-to-reach population and can serve as a feasible model of care for further expansion.

Hepatitis C virus cascade of care among people who inject drugs in Australia: Factors associated with testing and treatment in a universal healthcare system

BACKGROUND

Understanding factors associated with engagement across the hepatitis C virus (HCV) cascade of care (CoC) among people who inject drugs (PWID) is critical for developing targeted interventions to enhance engagement and further HCV elimination efforts. We describe the CoC among Australian PWID, and identify factors associated with engagement at each stage.

METHODS

As part of the 2018 and 2019 Illicit Drug Reporting System, Australians who regularly inject drugs reported lifetime HCV antibody and RNA testing, treatment uptake and completion. Multivariable logistic regression identified characteristics associated with outcomes.

RESULTS

Of 1499 participants, 87% reported antibody testing. Of those, 70% reported RNA testing, of whom 60% reported being RNA positive. Among those, 76% reported initiating treatment, 78% of whom completed. Incarceration history (adjusted odds ratio 1.90; 95% confidence interval 1.28-2.82), current opioid agonist treatment (OAT) (1.99; 1.14-3.47), and recent alcohol and other drug (AOD) counselling (2.22; 1.27-3.88) were associated with antibody testing. Incarceration history (1.42; 1.07-1.87), and current OAT (2.07; 1.51-2.86) were associated with RNA testing. Current OAT (1.92; 1.22-3.03) and recent AOD counselling (1.91; 1.16-3.13) were associated with treatment uptake. Methamphetamine as drug injected most often in the last month was associated with reduced odds of antibody (0.41; 0.25-0.66) and RNA testing (0.54; 0.40-0.74), compared to heroin.

CONCLUSION

CoC engagement amongst Australian PWID is encouraging, with AOD service engagement associated with testing and treatment. Further efforts to reach those not service engaged, particularly those not receiving OAT or who predominantly inject methamphetamine, are needed to achieve HCV elimination targets.

Patient Centeredness in Hepatitis C Direct-Acting Antiviral Treatment Delivery to People Who Inject Drugs: A Scoping Review

BACKGROUND AND OBJECTIVE

Patient-centered care (PCC) is crucial for value-based care. We aimed to assess PCC dimensions addressed in hepatitis C virus direct-acting antiviral treatment delivery to people who inject drugs.

METHODS

We conducted a scoping review to identify the studies that described hepatitis C virus treatment delivery to people who inject drugs in the direct-acting antiviral treatment era. We analyzed the included studies against eight PCC dimensions: (1) access to care; (2) coordination and integration of care; (3) continuity and translation; (4) physical comfort; (5) information, education, and communication; (6) emotional support; (7) involvement of family and friends; and (8) respect for individual patient preferences, perceived needs, and values. Additionally, we assessed the use of patient-centered terminology and the recognition of PCC importance and its relevance to treatment outcomes.

RESULTS

None of the identified 36 studies addressed all PCC dimensions (highest seven, lowest two). Our findings revealed that PCC dimensions are prioritized differently and addressed using different approaches and strategies. Studies that used PCC terminology referred to personalized activities, which does not imply comprehensive PCC. About one-third of the studies acknowledged the importance of patient centeredness and two-thirds recognized its relevance to treatment outcomes.

CONCLUSIONS

Our findings suggest more engagement of people who inject drugs and comprehensive involvement of their families and friends in hepatitis C virus treatment journey, decisions, and outcomes. The recognition of PCC importance and its relevance to treatment outcomes in the analyzed studies emphasizes the need for more patient-centered hepatitis C virus treatment for people who inject drugs.

Efficacy and safety of ledipasvir/sofosbuvir for hepatitis C among drug users: a systematic review and meta-analysis

BACKGROUND AND AIMS

Limited data is available on the efficacy of direct acting anti-viral drugs on hepatitis C in drug users. The aim of this meta-analysis was to comprehensively analyze the efficacy and safety of LDV/SOF in drug users infected with the hepatitis C virus (HCV).

METHODS

The PubMed, Cochrane library, Embase and Web of Science databases were searched for articles published till April 2021 on HCV-positive drug users who were treated with ledipasvir/sofosbuvir (LDV/SOF). The primary endpoint was pooled sustained virological response at 12 weeks (SVR12) with 95% confidence interval (95% CI). Funnel plots and Egger's test were used to assess the publication bias.

RESULTS

A total of 12 studies and 711 subjects treated with LDV/SOF-based regimen for HCV were included, and the pooled SVR12 rate was 89.8% (95% CI 85.9-92.7). The pooled SVR12 rate of genotype 1 drug users was 92.4% (95% CI 88.6-95.0). Subgroup analysis showed that pooled SVR12 rates of patients treated with LDV/SOF and LDV/SOF ± RBV were 89.2% (95% CI 83.4-93.1), 90.4% (95% CI 83.6-94.5) respectively. In addition, the SVR12 rates were 88% (95% CI 70.7-95.7) for 8 weeks, 89.9% (95% CI 81.0-94.9) for 12 weeks and 82.2% (95% CI 24.9-98.5) for 24 weeks of treatment.

CONCLUSION

LDV/SOF is a safe and relatively effective treatment for hepatitis C in drug users.

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.

EASL recommendations on treatment of hepatitis C: Final update of the series☆

Hepatitis C virus (HCV) infection is a major cause of chronic liver disease, with approximately 71 million chronically infected individuals worldwide. Clinical care for patients with HCV-related liver disease has advanced considerably thanks to an enhanced understanding of the pathophysiology of the disease, as well as developments in diagnostic procedures and improvements in therapy and prevention. These therapies make it possible to eliminate hepatitis C as a major public health threat, as per the World Health Organization target, although the timeline and feasibility vary from region to region. These European Association for the Study of the Liver recommendations on treatment of hepatitis C describe the optimal management of patients with recently acquired and chronic HCV infections in 2020 and onwards.

High prevalence of Hepatitis C Virus infection among people who use crack cocaine in an important international drug trafficking route in Central-West Region Brazil

In this study, the prevalence rate, associated risk factors and genetic diversity of hepatitis C virus (HCV) infection were determined among people who use crack from an international drug trafficking route in Central-West, Brazil. Blood samples were collected from 700 users of crack from Campo Grande and two border cities of Mato Grosso do Sul State and tested for HCV infection using serological and molecular testing methodologies. Anti-HCV was detected in 31/700 (4.5%, 95% CI: 2.9-6.0%) and HCV RNA in 26/31 (83.9%) of anti-HCV positive samples. Phylogenetic analysis of three HCV sub-genomic regions (5'UTR, NS5B and HVR-1) revealed the circulation of 1a (73.9%), 1b (8.7%) and 3a (17.4%) genotypes. Next-generation sequencing and phylogenetic analysis of intra-host viral populations of HCV HVR-1 showed a significant variation in intra-host genetic diversity among infected individuals, with 58.8% composed of more than one sub-population. Bayesian analysis estimated that the most recent common HCV ancestor for strains identified here was introduced to this region after 1975 following expansion of intravenous drug use in Brazil. Multivariate analyses showed that only 'ever having injected drugs' was independently associated with HCV infection. These results indicate an increasing spread of multiple HCV strains requiring public health intervention, such as harm reduction, testing services and treatment among crack users in this important border region of Central Brazil.

High prevalence of injection drug use and blood-borne viral infections among patients in an urban emergency department

Background

The opioid epidemic has led to an increase in the number of persons who inject drugs, and this population accounts for 12% of new human immunodeficiency virus (HIV) and 60% of new hepatitis C virus (HCV) infections in the United States annually. While persons who inject drugs disproportionately utilize the emergency department (ED), accurate data is lacking on the prevalence and patterns of injection drug use, and prevalence of co-occurring HIV and HCV infections among ED patients.

Objective

The primary outcome was to assess the prevalence of injection drug use and co-occurring HIV and HCV infection among patients presenting to an urban ED.

Methods

This was a cross sectional study conducted at an urban ED, with an annual census of 65,000 visits. A closed-response questionnaire was developed based on publicly available validated surveys to assess patterns of injection drug use and HIV and HCV infection status, and administered by trained research assistants to all registered adult patients during 4-hour blocks of time.

Results

Of the 2,319 eligible patients, 2,200 (94.9%) consented and completed the survey. 241 (11.0%) had ever used injection drugs, 103 (4.7%) currently used injection drugs, and 138 (6.3%) formerly used injection drugs. White patients age 25 to 34 years and white patients age 55 to 64 years had the highest prevalence of current (25.6%) and former (27.1%) injection drug use, respectively. Persons who use injection drugs had a higher prevalence of HCV infection (52.7% vs. 3.4%) and HIV infection (6.2% vs. 1.8%) than the rest of the population.

Conclusion

A high prevalence of ED patients report injection drug use, and this population self-reports a high prevalence of HIV and HCV infection. Emergency departments are in a unique position to engage with this population with regards to substance use treatment and linkage to care for HIV and HCV infection.

Patterns of Drug and Alcohol Use and Injection Equipment Sharing Among People With Recent Injecting Drug Use or Receiving Opioid Agonist Treatment During and Following Hepatitis C Virus Treatment With Direct-acting Antiviral Therapies: An International Study

BACKGROUND

In many settings, recent or prior injection drug use remains a barrier to accessing direct-acting antiviral treatment (DAA) for hepatitis C virus (HCV) infection. We examined patterns of drug and alcohol use and injection equipment sharing among people with recent injecting drug use or receiving opioid agonist treatment (OAT) during and following DAA-based treatment.

METHODS

SIMPLIFY and D3FEAT are phase 4 trials evaluating the efficacy of DAA among people with past 6-month injecting drug use or receiving OAT through a network of 25 international sites. Enrolled in 2016-2017, participants received sofosbuvir/velpatasvir (SIMPLIFY) or paritaprevir/ritonavir/dasabuvir/ombitasvir ± ribavirin (D3FEAT) for 12 weeks and completed behavioral questionnaires before, during, and up to 2 years posttreatment. The impact of time in HCV treatment and follow-up on longitudinally measured longitudinally measured behaviors was estimated using generalized estimating equations.

RESULTS

At screening, of 190 participants (mean age, 47 years; 74% male), 62% reported any past-month injecting 16% past-month injection equipment sharing, and 61% current OAT. Median alcohol use was 2 (Alcohol Use Disorders Identification Test-Consumption; range, 1-12). During follow-up, opioid injecting (odds ratio [OR], 0.95; 95% confidence interval [CI], 0.92-0.99) and sharing (OR, 0.87; 95% CI, 0.80-0.94) decreased, whereas no significant changes were observed for stimulant injecting (OR, 0.98; 95% CI, 0.94-1.02) or alcohol use (OR, 0.99; 95% CI, 0.95-1.04).

CONCLUSIONS

Injecting drug use and risk behaviors remained stable or decreased following DAA-based HCV treatment. Findings further support expanding HCV treatment to all, irrespective of injection drug use.

CLINICAL TRIALS REGISTRATION

SIMPLIFY, NCT02336139; D3FEAT, NCT02498015.

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.

Estimating the Population Size of People Who Inject Drugs in Malaysia for 2014 and 2017 Using the Benchmark-Multiplier Method

Background: As hepatitis C elimination efforts are launched, national strategies for screening and treatment scale-up in countries, such as Malaysia, must be designed and implemented. Strategic information, including estimates of the total number of patients chronically-infected with hepatitis C virus (HCV) and the size of key populations, such as people who inject drugs (PWID), is critical to informing these efforts. For Malaysia, the estimate of the PWID population size most frequently reported in global systematic reviews is for the year 2009. Objectives: To support ongoing national HCV planning efforts, we aimed to estimate the national population size of active PWID in Malaysia, for the years 2014 and 2017. Methods: To estimate the PWID population size, we applied standard benchmark-multiplier methodology, frequently used for PWID population size estimation, and extended it by adjusting for cessation of injecting drug use within the benchmark and calculating statistical uncertainty intervals. Results: The estimated active PWID population size was 153,000 (95% uncertainty interval (UI): 136,000-172,000) for 2014 and 156,000 (95% UI: 137,000-188,000) for 2017. Conclusions/importance: This updated estimate of the active PWID population size in Malaysia will help inform effective planning for the scale-up of HCV screening and treatment services. The proposed methodology is applicable to other countries that maintain national HIV registries and have conducted Integrated Biological and Behavioral Surveys among active PWID.

Elimination of hepatitis C virus infection among people who use drugs: Ensuring equitable access to prevention, treatment, and care for all

There have been major strides towards the World Health Organization goal to eliminate hepatitis C virus (HCV) infection as a global public health threat. The availability of simple, well-tolerated direct-acting antiviral therapies for HCV infection that can achieve a cure in >95% of people has provided an important tool to help achieve the global elimination targets. Encouragingly, therapy is highly effective among people receiving opioid agonist therapy and people who have recently injected drugs. Moving forward, major challenges include ensuring that new infections are prevented from occurring and that people who are living with HCV are tested, linked to care, treated, receive appropriate follow-up, and have equitable access to care. This editorial highlights key themes and articles in a special issue focusing on the elimination of HCV among people who inject drugs. An overarching consideration flowing from this work is how to ensure equitable access to HCV treatment and care for all. This special issue maps the field in relation to: HCV prevention; the cascade of HCV care; strategies to enhance testing, linkage to care, and treatment uptake; and HCV treatment and reinfection. In addition, papers draw attention to the 'risk environments' and socio-ecological determinants of HCV acquisition, barriers to HCV care, the importance of messaging around the side-effects of new direct-acting antiviral therapies, the positive transformative potential of treatment and cure, and the key role of community-based drug user organizations in the HCV response. While this special issue highlights some successful efforts towards HCV elimination among people who inject drugs, it also highlights the relative lack of attention to settings in which resources enabling elimination are scarce, and where elimination hopes and potentials are less clear, such as in many low and middle income countries. Strengthening capacity in areas of the world where resources are more limited will be a critical step towards ensuring equity for all so that global HCV elimination among PWID can be achieved.

Directly observed hepatitis C treatment with opioid substitution therapy in community pharmacies: A qualitative study

BACKGROUND

The hepatitis C virus (HCV) will only be eliminated through successful engagement with people who inject drugs (PWID), however some of this population experience socioeconomic and individual issues that can lead to poor HCV treatment adherence. A key sub-group of (PWID) are those who receive opioid substitution therapy (OST). In Australia, OST is most often delivered under direct supervision by a community pharmacist every day or multiple times a week. This regular interaction could be an ideal opportunity to enhance direct-acting antiviral (DAA) treatment adherence under directly observed therapy (DOT) by the pharmacist.

AIM

The aim of this study was to explore the perspectives of OST patients with a lived experience of HCV to understand whether or not dispensing DAAs in the same way as, or simultaneously with OST would benefit HCV treatment.

METHODS

Data collection occurred from June to August 2017. Semi-structured interviews were conducted with a sample of PWID living with HCV and on OST programs (n = 12) in Melbourne, Australia. Interviews were voice recorded and transcribed in verbatim. Interpretive phenomenology guided analysis of the data.

RESULTS

Themes reported by participants that provide insight into the suitability of DOT of DAAs include: Adherence and non-adherence to DAA treatment; Mixed views towards DOT of DAAs; Experiences and perceptions of OST providers; and Perceived stigma in the pharmacy.

CONCLUSIONS

Community pharmacies offering OST may be an effective place for DOT of HCV treatment, but is likely only to benefit people who face significant challenges to adherence. We suggest that a positive pharmacist-patient relationship, high OST adherence, and commitment to reducing stigma in the pharmacy would be necessary for the intervention to be effective. Further research is needed to evaluate the expanded-role of community pharmacies in improving DAA adherence and eliminating HCV.

Reinfection by hepatitis C virus following effective all-oral direct-acting antiviral drug therapy in HIV/hepatitis C virus coinfected individuals

OBJECTIVES

We analysed hepatitis C virus (HCV) reinfection among participants in a prospective registry of HIV/HCV-coinfected patients treated with all-oral direct-acting antiretroviral (DAA)-based therapy in the region of Madrid.

DESIGN

An observational cohort study.

METHODS

The study period started on the date sustained viral response (SVR) was confirmed. The censoring date was 31 December 2017. SVR was defined as negative HCV-RNA 12 weeks after completion of treatment. Reinfection was defined as a positive HCV-RNA test result after achievement of SVR.

RESULTS

Reinfections were detected in 17 of 2359 HIV/HCV-coinfected patients (0.72%) overall, in 12 out of 177 (6.78%) MSM and in five out of 1459 (0.34%) people who inject drugs (PWID). The incidence of reinfection [95% confidence interval (95% CI)] per 100 person-years was 0.48 (0.30-0.77) overall, 5.93 (3.37-10.44) for MSM and 0.21 (0.09-0.52) for PWID. Reinfections were detected a median of 15 weeks (interquartile range 13-26) after SVR. In 10 (58.82%) patients, the reinfection was caused by a different HCV genotype. All 12 MSM with reinfection acknowledged unprotected anal intercourse with several partners, seven used chemsex, six reported fisting and four practiced slamming. A concomitant STI was detected in five patients. Four IDU with reinfection reported injecting drugs following SVR.

CONCLUSION

HCV reinfection is a matter of concern in HIV-positive MSM treated with all-oral DAA therapy in the region of Madrid. Our data suggest that prevention strategies and frequent testing with HCV-RNA should be applied following SVR in MSM who engage in high-risk practices.

Test uptake and hepatitis C prevalence in 5483 Danish people in drug use treatment from 1996 to 2015: a registry-based cohort study

BACKGROUND AND AIMS

The aims of this study were, in people in treatment for drug use in Funen, Denmark, to: (1) assess prevalence of hepatitis C virus (HCV) test uptake and prevalence of HCV; (2) identify predictors of test update and HCV infection; and (3) characterize changes between 1996 and 2015 in test uptake, HCV prevalence and drug use.

DESIGN

Cohort study linking the Danish National Registry on Drug Users in Treatment to the regional hepatitis test registry and the Danish Death Certificate Registry, thus combining longitudinal data on drug use with data on HCV testing and results.

SETTING AND PARTICIPANTS

People recorded as having received treatment for drug use between 1996 and 2015 (n = 5483) in Funen, Denmark. In the cohort, 24.8% were female, median age 23 years [interquartile range (IQR) = 20-32] at entry and 50% had self-reported injecting or had received opiate substitution therapy (OST).

MEASUREMENTS

The main outcomes were the test for HCV ever and latest HCV-RNA being positive. The main predictors were for test and infection investigated; ever receiving OST, self-reported injecting, age at entry and connection to treatment centre offering outreach hepatitis care.

FINDINGS

HCV test uptake was 52% and prevalence of current HCV-RNA+ was 21% in people alive at the end of follow-up. Positive predictors of having undergone HCV testing were: receiving OST [odds ratio (OR) = 3.7; 95% confidence interval (CI) = 3.2-4.5], self-reported injecting (OR = 2.3; 95% CI = 2.0-2.7), female gender (OR = 1.7; 95% CI = 1.4-1.9) and having been connected to centres with outreach hepatitis care (OR = 1.4; 95% CI = 1.2-1.7). In people alive, HCV-RNA+ prevalence was 31% if ever on OST or self-reported injecting. Among HCV-infected people, 69% were in drug use treatment at end of follow-up. For participants entering the cohort after 2010, only 5% reported opiates as main drug of use and 17% had experience of injecting.

CONCLUSION

Among Danish people in treatment for drug use from 1996 to 2015, receiving opiate substitution therapy had the largest associating to being tested for hepatitis C virus. As opiate use is declining, adapting test strategies will be necessary.

Strategies to Reduce Hepatitis C Virus Reinfection in People Who Inject Drugs

Reinfection after direct-acting antiviral therapy may pose a challenge to hepatitis C virus elimination efforts. Reinfection risk is cited as a reason for not offering treatment to people who inject drugs. As treatment scale-up expands among populations with risks for reacquisition, acknowledgment that reinfection can and will occur is essential. Efforts to prevent and manage reinfection should be incorporated into individual- and population-level strategies. The risk of reinfection after successful treatment emphasises the need for education, harm reduction, and posttreatment surveillance. Reinfection must not be considered an impediment to treatment, if hepatitis C virus elimination is to be achieved.

Direct-acting antiviral treatment for hepatitis C among people who use or inject drugs: a systematic review and meta-analysis

BACKGROUND

There are concerns around poorer response to direct-acting antiviral (DAA) therapy for hepatitis C virus infection among people who use drugs. This systematic review assessed DAA treatment outcomes among people with recent drug use and those receiving opioid substitution therapy.

METHODS

Bibliographic databases and conference presentations were searched for observational studies and clinical trials assessing DAA treatment completion, sustained virological response (SVR), and loss to follow-up among people with recent drug use (injecting or non-injecting) and those receiving opioid substitution therapy. Meta-analysis was used to pool estimates and meta-regression to explore heterogeneity.

FINDINGS

38 eligible studies, with 3634 participants, were included. The definition of recent drug use varied across studies, with drug use in the past 6 months and at the initiation of or during DAA therapy most commonly used. Among individuals with recent injecting or non-injecting drug use (21 studies; 1408 participants), treatment completion was 97·5% (95% CI 96·6-98·3) and SVR was 87·7% (95% CI 84·2-91·3). Among individuals receiving opioid substitution therapy (36 studies; 2987 participants), treatment completion was 97·4% (95% CI 96·5-98·3) and SVR was 90·7% (95% CI 88·5-93·0). Among individuals with recent injecting drug use (eight studies; 670 participants), treatment completion was 96·9% (95% CI 95·6-98·2) and SVR was 87·4% (95% CI 82·0-92·8). In meta-regression analysis, clinical trials (vs observational studies; adjusted odd ratio 2·18, 95% CI 1·27-3·75; p=0·006) and higher mean or median age (1·07, 1·02-1·12; p=0·008) were significantly associated with higher SVR. Clinical trials (0·45, 0·22-0·94; p=0·033) and older age (0·94, 0·88-0·99; p=0·034) were also significantly associated with a lower proportion of participants lost to follow-up.

INTERPRETATION

Response to DAA therapy was favourable among people with recent drug use (including those who inject) and those receiving opioid substitution therapy, supporting broadening access in these populations.

FUNDING

The Kirby Institute, UNSW Sydney, and National Health and Medical Research Council of Australia.

Sofosbuvir-Based Direct-Acting Antiviral Therapies for HCV in People Receiving Opioid Substitution Therapy: An Analysis of Phase 3 Studies

Background

Hepatitis C virus (HCV) direct-acting antiviral therapy is effective among people receiving opioid substitution therapy (OST), but studies are limited by small numbers of nongenotype 1 (GT1) patients. The aim of this study was to evaluate the treatment completion, adherence, SVR12, and safety of sofosbuvir-based therapies in HCV patients receiving and not receiving OST.

Methods

Ten phase 3 studies of sofosbuvir-based regimens included ION (ledipasvir/sofosbuvir ± ribavirin for 8, 12, or 24 weeks in GT1), ASTRAL (sofosbuvir/velpatasvir for 12 weeks in GT1-6), and POLARIS (sofosbuvir/velpatasvir and sofosbuvir/velpatasvir/voxilaprevir in GT1-6). Patients with clinically significant drug use (last 12 months) or noncannabinoids detected at screening were ineligible.

Results

Among 4743 patients, 4% (n = 194) were receiving OST (methadone; n = 113; buprenorphine, n = 75; other, n = 6). Compared with those not receiving OST (n = 4549), those receiving OST (n = 194) were younger (mean age, 48 vs 54), more often male (73% vs 61%), GT3 (38% vs 17%), treatment-naïve (78% vs 65%), and cirrhotic (36% vs 23%). Among those receiving and not receiving OST, there was no significant difference in treatment completion (97% vs 99%, P = .06), SVR12 (94% vs 97%, P = .06), relapse (0.5% vs 2.1%, P = .19), adverse events (78% vs 77%, P = .79), or serious adverse events (3.6% vs 2.4%, P = .24). There was no difference in SVR12 in patients with cirrhosis (99% vs 95%, P = .25) or those with G3 (95% vs 95%, P = .77) in those receiving OST. Among patients receiving OST, SVR12 was high among those receiving methadone (95%) and buprenorphine (96%).

Conclusion

Sofosbuvir-based therapies are effective and safe in patients receiving OST.

Complex patterns of Hepatitis-C virus longitudinal clustering in a high-risk population

We investigated longitudinal viral clustering among and within subjects in a highly networked cohort of people who inject drugs (PWID). All subjects had estimated dates of infection and two or more E1 sequences (bp 943-1288 relative to H77) with 1 to 14years of follow up. Two methods (HIV-TRACE and PhyloPart) were used to determine clusters. Genetic distance thresholds were determined by comparing intra-and inter-host distances. Additional phylogenetic analysis was performed on subjects with complicated viral histories. At the optimal threshold of 3.9%, HIV-TRACE found 77 clusters and PhyloPart found 63 clusters, of which 27 and 32 contained multiple subjects, respectively. Furthermore, 1/3 of the subjects had sequences in different clusters over the course of the study, including some cases in which a later-sampled sequence matched a cluster detected much earlier in the infection, despite being separated by RNA-negative lab visit and detection of sequences in different clusters. A detailed phylogenetic analysis of four subjects with such patterns showed that in all four cases, the earlier and later variants grouped closely on the tree, and did not group with concurrent sequences from any other subject. These observations suggest that subjects are either experiencing rapid and recurring infection-clearance-reinfection cycles from the same source, or a single transmission event produces a chronic infection that may go undetected and/or co-circulate with different viruses from separate transmission events. Furthermore, our results show the utility of using longitudinal sampling to obtain a more comprehensive view of the viral linkages in high-risk populations.

Direct-acting antiviral agents for HCV infection affecting people who inject drugs

Globally, 12 million people are estimated to have injected drugs in the past year, 50% of whom have chronic HCV infection, with people who have previously injected drugs presenting an additional large reservoir of infection. The availability of simple and tolerable interferon-free direct-acting antiviral agents (DAAs) for HCV infection, which have a cure rate of >95% represents one of the most exciting advances in clinical medicine in the past few decades. Adherence and response to DAA therapy among people who inject drugs (PWID) receiving opioid substitution therapy (OST) in clinical trials are comparable to populations without a history of injecting drugs. Further data are required among current PWID not receiving OST. Given the potential prevention benefits of treatment, DAAs have enhanced cost-effectiveness among PWID. As HCV therapy is expanded to populations of PWID with high-risk behaviours for re-exposure, acknowledgement that HCV reinfection will occur is crucial, and appropriate strategies must be in place to maximize prevention of reinfection and offer retreatment for reinfection. This Review will also discuss essential components for broadening access to HCV care for PWID as we strive for the global elimination of HCV infection.

HCV Cure and Reinfection Among People With HIV/HCV Coinfection and People Who Inject Drugs

PURPOSE OF REVIEW

Highly effective, well-tolerated interferon-free direct-acting antivirals (DAA) have revolutionised hepatitis C virus (HCV) therapeutics, with the opportunity for broad treatment scale-up among marginalised or "high-risk" populations, including people who inject drugs (PWID) and people with HIV/HCV coinfection.

RECENT FINDINGS

Concern that HCV reinfection may compromise HCV treatment outcomes is sometimes cited as a reason for not offering treatment to current and former PWID. However, the incidence of reinfection following interferon-based treatment for chronic HCV is low among PWID. Reinfection rates in HIV-positive men-who-have-sex-with-men (MSM) are varied, with high incidence reported in some cohorts. Mathematical modelling suggests that substantial reductions in HCV incidence and prevalence could be achieved with targeted DAA therapy among those at the highest risk of ongoing transmission. This review will summarise the recent literature on DAA efficacy in PWID and people with HIV/HCV coinfection, discuss the individual- and population-level impact of DAA treatment scale-up and reinfection, and highlight ongoing and future research questions in expanding HCV care and treatment to those populations at high risk of ongoing HCV transmission.

Research priorities to achieve universal access to hepatitis C prevention, management and direct-acting antiviral treatment among people who inject drugs

Globally, it is estimated that 71.1 million people have chronic hepatitis C virus (HCV) infection, including an estimated 7.5 million people who have recently injected drugs (PWID). There is an additional large, but unquantified, burden among those PWID who have ceased injecting. The incidence of HCV infection among current PWID also remains high in many settings. Morbidity and mortality due to liver disease among PWID with HCV infection continues to increase, despite the advent of well-tolerated, simple interferon-free direct-acting antiviral (DAA) HCV regimens with cure rates >95%. As a result of this important clinical breakthrough, there is potential to reverse the rising burden of advanced liver disease with increased treatment and strive for HCV elimination among PWID. Unfortunately, there are many gaps in knowledge that represent barriers to effective prevention and management of HCV among PWID. The Kirby Institute, UNSW Sydney and the International Network on Hepatitis in Substance Users (INHSU) established an expert round table panel to assess current research gaps and establish future research priorities for the prevention and management of HCV among PWID. This round table consisted of a one-day workshop held on 6 September, 2016, in Oslo, Norway, prior to the International Symposium on Hepatitis in Substance Users (INHSU 2016). International experts in drug and alcohol, infectious diseases, and hepatology were brought together to discuss the available scientific evidence, gaps in research, and develop research priorities. Topics for discussion included the epidemiology of injecting drug use, HCV, and HIV among PWID, HCV prevention, HCV testing, linkage to HCV care and treatment, DAA treatment for HCV infection, and reinfection following successful treatment. This paper highlights the outcomes of the roundtable discussion focused on future research priorities for enhancing HCV prevention, testing, linkage to care and DAA treatment for PWID as we strive for global elimination of HCV infection.

Elimination of HCV as a public health concern among people who inject drugs by 2030 - What will it take to get there?

INTRODUCTION

Globally, there is a considerable burden of HCV and HIV infections among people who inject drugs (PWID) and transmission of both infections continues. Needle and syringe programme (NSP) and opioid substitution therapy (OST) coverage remains low, despite evidence demonstrating their prevention benefit. Direct-acting antiviral therapies (DAA) with HCV cure >95% among PWID provide an opportunity to reverse rising trends in HCV-related morbidity and mortality and reduce incidence. However, HCV testing, linkage to care, and treatment remain low due to health system, provider, societal, and patient barriers. Between 2015 and 2030, WHO targets include reducing new HCV infections by 80% and HCV deaths by 65%, and increasing HCV diagnoses from <5% to 90% and number of eligible persons receiving HCV treatment from <1% to 80%. This commentary discusses why PWID should be considered as a priority population in these efforts, reasons why this goal could be attainable among PWID, challenges that need to be overcome, and key recommendations for action.

DISCUSSION

Challenges to HCV elimination as a global health concern among PWID include poor global coverage of harm reduction services, restrictive drug policies and criminalization of drug use, poor access to health services, low HCV testing, linkage to care and treatment, restrictions for accessing DAA therapy, and the lack of national strategies and government investment to support WHO elimination goals. Key recommendations for action include reforming drug policies (decriminalization of drug use and/or possession, or providing alternatives to imprisonment for PWID; decriminalization of the use and provision of sterile needles-syringes; and legalization of OST for people who are opioid dependent), scaling up and improving funding for harm reduction services, making health services accessible for PWID, supporting community empowerment and community-based programmes, improving access to affordable diagnostics and medicines, and eliminating stigma, discrimination, and violence against PWID.

CONCLUSIONS

The ambitious targets for HCV elimination set by WHO are achievable in many countries, but will require researchers, healthcare providers, policy makers, affected communities, advocates, the pharmaceutical and diagnostics industries, and governments around the world to work together to make this happen.

Chronic hepatitis C and individuals with a history of injecting drugs in Spain: population assessment, challenges for successful treatment

In Spain, there is a need to improve chronic hepatitis C care among people who inject drugs (PWID). Injecting drug use is an important risk behaviour for hepatitis C virus (HCV) infection. Review of 28 sources of the relevant published literature mapped the size of the addiction-HCV population in Spain. Experts in opioid use disorder (OUD) treatment in Spain completed a consensus to define the population size, HCV prevalence and access or barriers to hepatitis C treatment for PWID populations. In Spain, over 300 000 individuals have a lifetime history of injecting drugs. Currently, 150 000 individuals in Spain have OUD; many have injected drugs. Each year, 80 000 individuals engage with treatment services for OUD. A proportion of this group continues to inject drugs. There is a high HCV prevalence in PWID - estimates of 60-80% in Spain. Uptake of hepatitis C therapy in PWID in Spain is limited; barriers include awareness of treatment pathways, advocacy for regular screening and effective joint care. There is an urgent need to address barriers to effective hepatitis C care for PWID in Spain. Practical and specific strategies including peer-led solutions, patient buddy systems and joint working models at the local level can make important short-term differences.

HCV reinfection incidence among individuals treated for recent infection

One challenge to HCV elimination through therapeutic intervention is reinfection. The aim of this analysis was to calculate the incidence of HCV reinfection among both HIV-positive and HIV-negative individuals treated for recent HCV infection (estimated infection duration <18 months). Individuals with recent HCV infection who achieved an end-of-treatment response in four open-label studies between 2004 and 2015 in Australia and New Zealand were assessed for HCV reinfection, confirmed by sequencing of the Core-E2 and/or NS5B regions. Reinfection incidence was calculated using person-time of observation. Exact Poisson regression analysis was used to assess factors associated with HCV reinfection. The cohort at risk for reinfection (n=120; 83% male; median age 36 years) was composed of HIV-positive men-who-have-sex-with-men (53%) and people who inject drugs (current 49%, ever 69%). Total follow-up time at risk was 135 person-years (median 1.08 years, range 0.17, 2.53). Ten cases of HCV reinfection were identified, for an incidence of 7.4 per 100 py (95% CI 4.0, 13.8). Reinfection incidence was significantly higher among participants who reported injection drug use at end of or post-treatment, irrespective of HIV status (15.5 per 100 py, 95% CI 7.8, 31.1). In adjusted analysis, factors associated with reinfection were older age (aIRR 5.3, 95% CI 1.15, 51.5, P=.042) and injection drug use at end of or post-treatment (aIRR 7.9, 95% CI 1.6, 77.2, P=.008). High reinfection incidence following treatment for recent HCV infection in individuals with ongoing risk behaviour emphasizes the need for post-treatment surveillance, harm reduction strategies and education in at-risk populations.

Efficacy and Safety of Ledipasvir/Sofosbuvir With and Without Ribavirin in Patients With Chronic HCV Genotype 1 Infection Receiving Opioid Substitution Therapy: Analysis of Phase 3 ION Trials

BACKGROUND

 Interferon-based hepatitis C virus (HCV) therapy is safe and effective among people receiving opioid substitution therapy (OST), but treatment uptake remains low. Our aim was to evaluate the impact of OST and drug use during therapy on completion, adherence, sustained virologic response (SVR12), and safety of ledipasvir/sofosbuvir ± ribavirin.

METHODS

 The phase 3 ION studies evaluated a fixed-dose combination of ledipasvir/sofosbuvir ± ribavirin administered for 8, 12, or 24 weeks in patients with chronic HCV genotype 1. People with clinically significant drug use (prior 12 months) or noncannabinoids detected at screening by urine drug tests (not explained by prescriptions) were ineligible. Stored samples were available from ION-1 for retrospective testing for illicit drugs by enzyme-linked immunosorbent assay.

RESULTS

 Among 1952 patients enrolled in the ION studies, 4% (n = 70) were receiving OST. Among those receiving (n = 70) and not receiving OST (n = 1882), there was no difference in treatment completion (97% vs 98%; P = .40), ≥80% adherence (93% vs 92%; P = 1.00), SVR12 (94% vs 97%; P = .28), and serious adverse events (4% vs 3%; P = .43), respectively. Among participants in the ION-1 trial, 23% (n = 196) used illicit drugs during therapy (15% cannabinoids alone; 8% other illicit drugs ± cannabinoids). There was no difference in treatment completion, ≥80% adherence, SVR12, or serious AEs in those with no drug use during treatment compared with those who used cannabinoids and/or other illicit drugs. No cases of HCV reinfection were observed in the 24 weeks following treatment.

CONCLUSIONS

 OST and drug use during HCV therapy did not impact treatment completion, adherence, SVR12, or safety.

CLINICAL TRIALS REGISTRATION

 ION-1 (NCT01701401); ION-2 (NCT01768286); and ION-3 (NCT01851330).

New treatments for hepatitis C virus (HCV): scope for preventing liver disease and HCV transmission in England

New direct-acting antivirals have the potential to transform the hepatitis C (HCV) treatment landscape, with rates of sustained viral response in excess of 90%. As these new agents are expensive, an important question is whether to focus on minimizing the consequences of severe liver disease, or reducing transmission via 'treatment as prevention'. A back-calculation model was used to estimate the impact of treatment of mild, moderate and compensated cirrhosis on incident cases of HCV-related end-stage liver disease/hepatocellular carcinoma (ESLD/HCC). In addition, a dynamic model was used to determine the impact on incidence and prevalence of chronic infection in people who inject drugs (PWID), the main risk group in England. Treating 3500 cirrhotics per year was predicted to reduce ESLD/HCC incidence from 1100 (95% CrI 970-1240) cases per year in 2015 to 630 (95% CrI 530-770) in 2020, around half that currently expected, although treating moderate-stage disease will also be needed to sustain this reduction. Treating mild-stage PWID was required to make a substantial impact on transmission: with 2500 treated per year, chronic prevalence/annual incidence in PWID was reduced from 34%/4.8% in 2015 to 11%/1.4% in 2030. There was little overlap between the two goals: treating mild stage had virtually no impact on ESLD/HCC within 15 years, but the long timescale of liver disease means relatively few PWID reach cirrhosis before cessation of injecting. Strategies focussing on treating advanced disease have the potential for dramatic reductions in severe morbidity, but virtually no preventative impact.

Estimating the number of regular and dependent methamphetamine users in Australia, 2002-2014

OBJECTIVE

To estimate the number of regular and dependent methamphetamine users in Australia.

DESIGN

Indirect prevalence estimates were made for each year from 2002-03 to 2013-14. We applied multiplier methods to data on treatment episodes for amphetamines (eg, counselling, rehabilitation, detoxification) and amphetamine-related hospitalisations to estimate the numbers of regular (at least monthly) and dependent methamphetamine users for each year. Dependent users comprised a subgroup of those who used the drug regularly, so that estimates of the sizes of these two populations were not additive.

RESULTS

We estimated that during 2013-14 there were 268 000 regular methamphetamine users (95% CI, 187 000-385 000) and 160 000 dependent users (95% CI, 110 000-232 000) aged 15-54 years in Australia. This equated to population rates of 2.09% (95% CI, 1.45-3.00%) for regular and 1.24% (95% CI, 0.85-1.81%) for dependent use. The rate of dependent use had increased since 2009-10 (when the rate was estimated to be 0.74%), and was higher than the previous peak (1.22% in 2006-07). The highest rates were consistently among those aged 25-34 years, in whom the rate of dependent use during 2012-2013 was estimated to be 1.50% (95% CI, 1.05-2.22%). There had also been an increase in the rate of dependent use among those aged 15-24 years (in 2012-13 reaching 1.14%; 95% CI, 0.80-1.69%).

CONCLUSIONS

There have been increases over the past 12 years in the numbers of regular and dependent methamphetamine users in Australia. Our estimates suggest that the most recent numbers are the highest for this period, and that the increase has been most marked among young adults (those aged 15-34 years).

IMPLICATIONS

There is an increasing need for health services to engage with people who have developed problems related to their methamphetamine use.

Review article: treatment as prevention - targeting people who inject drugs as a pathway towards hepatitis C eradication

BACKGROUND

Hepatitis C virus (HCV) is a leading cause of chronic liver disease worldwide. HCV predominates in people who inject drugs; a group in whom anti-viral therapy has previously been withheld on the basis of chaotic lifestyles and associated risks of reinfection. New research has emerged which suggests that by specifically targeting HCV-infected people who inject drugs for treatment, the pool of HCV would deplete, thus reducing overall transmission and eventually leading to HCV eradication.

AIM

To outline the requirements for HCV eradication and review the evidence that this is achievable.

METHODS

Expert review of the literature.

RESULTS

The achievement of HCV eradication using 'treatment as prevention' is supported by numerous epidemiological modelling studies employing a variety of models in several contexts including people who inject drugs, men who have sex with men and prisoners. More recent studies also incorporate the newer, more efficacious direct-acting anti-viral drugs. These drugs have been shown to be safe and effective in people who inject drugs in clinical trials. There is no empirical evidence of the impact of treatment as prevention strategies on population prevalence.

CONCLUSIONS

This review highlights the efforts to control HCV and evaluates the possibilities of achieving eradication of HCV. Currently, the technologies required to achieve HCV eradication exist, but the infrastructure to deliver them is not generally available or of insufficient scale outside of specific areas. Such areas are yet to demonstrate that elimination is possible, but results of studies in these areas are awaited. Such a demonstration would be proof of principle for eradication. Although we are aspiring towards HCV eradication, elimination is the more realistic prospect.

Recommendations for the management of hepatitis C virus infection among people who inject drugs

In high income countries, the majority of new and existing hepatitis C virus (HCV) infections occur among people who inject drugs (PWID). In many low and middle income countries large HCV epidemics have also emerged among PWID populations. The burden of HCV-related liver disease among PWID is increasing, but treatment uptake remains extremely low. There are a number of barriers to care which should be considered and systematically addressed, but should not exclude PWID from HCV treatment. The rapid development of interferon-free direct-acting antiviral (DAA) therapy for HCV infection has brought considerable optimism to the HCV sector, with the realistic hope that therapeutic intervention will soon provide near optimal efficacy with well-tolerated, short duration, all oral regimens. Further, it has been clearly demonstrated that HCV treatment is safe and effective across a broad range of multidisciplinary healthcare settings. Given the burden of HCV-related disease among PWID, strategies to enhance HCV assessment and treatment in this group are urgently needed. These recommendations demonstrate that treatment among PWID is feasible and provide a framework for HCV assessment and care. Further research is needed to evaluate strategies to enhance testing, linkage to care, treatment, adherence, viral cure, and prevent HCV reinfection among PWID, particularly as new interferon-free DAA treatments for HCV infection become available.