Hepatitis C virus treatment as prevention in an extended network of people who inject drugs in the USA: a modelling study

Real-world hepatitis C prevalence and treatment uptake at opioid agonist therapy clinics in Ontario, Canada

Widespread screening for hepatitis C virus (HCV) is necessary for Canada to meet its HCV elimination goals by 2030. People who currently or previously injected drugs are at high risk for HCV. Opioid agonist therapy (OAT, such as methadone and buprenorphine) has been shown to help stabilize the lives of people who are opioid-dependent. The distribution of OAT in North America typically requires daily, weekly, or monthly clinic visits and presents an opportunity for engagement, screening and treatment for those at high-risk of HCV. In this study, HCV screening was conducted by staff at OAT clinics in Ontario from 2016 to 2020 and those with chronic infections were treated on-site with direct-acting antivirals. Point-of-care or dried blood spot (DBS) testing was used for antibodies, DBS or serum for HCV RNA and serum for HCV RNA at SVR12 (sustained virological response). Clinics screened 1954 people (mean age 40 years ±12, 63% male). Forty-five percent were antibody positive, of whom 64% were HCV RNA+. Eighty percent of those RNA+ set an appointment in which 99% attended. Ninety-six percent started treatment with 87% completing treatment. Sixty-eight percent of people who completed treatment submitted a sample for SVR12 testing of which 97% achieved a virological cure. Results suggest that HCV screening and treatment at OAT clinics is feasible, effective and warrants expansion. Data suggest strong treatment adherence due to high rates of SVR12 comparable with other OAT-based HCV treatment programs. The lack of SVR12 sampling could be addressed by either on-site phlebotomy or incentivizing SVR12 sampling.

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.

Social networks, secondary syringe exchange, and opioid agonist therapy retention among people who inject drugs in Hartford, CT

BACKGROUND

Opioid agonist therapies (OAT) and  harm reduction such as syringe service programs (SSP) have been shown to be effective in preventing adverse outcomes such as overdose deaths, HIV and Hepatitis C infections among people who inject drugs (PWID). The importance of social network influence on disease transmission is well established, yet the interplay between harm reduction and network structures is, generally, not well understood. This study aims to analyze how social networks can mediate the harm reduction effects associated with secondary exchange through syringe service programs (SSP) and opioid agonist therapies (OAT) among injection network members.

METHODS

Sociometric data on networks on people who inject drugs from Hartford, CT, which were collected in 2012-2013, provided assessment of risk behaviors among 1574 injection network members, including participation in OAT and SSP. Subject's network characteristics were examined in relation to retention in OAT, as well as secondary syringe exchange using exponential random graph model (ERGM) and regression.

RESULTS

Based on the analysis, we found that probability of individuals being retained in OAT was positively associated with the OAT retention status of their peers within the network. Using simulations, we found that higher levels of positive correlation of OAT retention among network members can result in reduced risk of transmission of HIV to network partners on OAT. In addition, we found that secondary syringe exchange engagement was associated with higher probability of sharing of paraphernalia and unsterile needles at the network level.

CONCLUSIONS

Understanding how networks mediate risk behaviors is crucial for making progress toward ending the HIV epidemic.

Hepatitis C

Hepatitis C virus (HCV) is a hepatotropic RNA virus that can cause acute and chronic hepatitis, with progressive liver damage resulting in cirrhosis, decompensated liver disease, and hepatocellular carcinoma. In 2016, WHO called for the elimination of HCV infection as a public health threat by 2030. Despite some progress, an estimated 57 million people were living with HCV infection in 2020, and 300 000 HCV-related deaths occur per year. The development of direct-acting antiviral therapy has revolutionised clinical care and generated impetus for elimination, but simplified and broadened HCV screening, enhanced linkage to care, and higher coverage of treatment and primary prevention strategies are urgently required.

Social Networks, Stigma, and Hepatitis C Care Among Women Who Inject Drugs: Findings from A Community Recruited Sample

This study explores the role of perceived HCV stigma and social networks on HCV care among people who inject drugs (PWID) of both sexes, and solely among women who inject drugs (WWID). Data were from 269 HCV positive PWID, community-recruited through street-based outreach in Baltimore, MD. We defined HCV stigma based on participants' perceptions of treatment by others and their need to conceal their HCV status. Among WWID, HCV stigma was linked with decreased odds of undergoing liver disease staging (aOR = 0.33, 95% CI: 0.13,0.85) or to have attempted to get the HCV cure (aOR = 0.39, CI: 0.16,0.97), these associations were not evident in the overall sample with both sexes. Social network characteristics were significant correlates of HCV care in the overall sample, and these associations were stronger among WWID. WWID with more HCV positive social network members had higher odds of an HCV-related healthcare visit in the prior 12 months (aOR = 4.28, CI: 1.29,14.17) and to have undergone liver disease staging (aOR = 2.85, CI: 1.01,8.05). WWID with more social network members aware of the HCV cure were more likely to report an attempt at obtaining the HCV cure (aOR = 5.25, CI: 1.85,14.89). Our results suggest complexity in the role of social networks and stigma on HCV care.

Sustained Virologic Response Rates Before and After Removal of Sobriety Restriction for Hepatitis C Virus Treatment Access

OBJECTIVES

Until November 1, 2018, Illinois Medicaid restricted coverage of hepatitis C virus (HCV) medication to patients with sobriety from alcohol and illicit substances for ≥12 months. This policy limited treatment access for patients with a high risk of HCV transmission, despite clinical trial and real-world data demonstrating high sustained virologic response (SVR) rates among patients with substance use. The objective of this study was to compare HCV SVR rates between patients treated before and after removal of the Illinois Medicaid sobriety restriction.

METHODS

We performed a retrospective cohort study of Medicaid-insured patients who completed direct-acting antiviral treatment at an urban, academic medical center in Illinois from January 1, 2014, through October 21, 2020. The primary endpoint was SVR. We compared group characteristics using χ2 or Fisher exact tests for categorical variables and Wilcoxon rank-sum tests for continuous variables. We used logistic regression to compare SVR rates before and after the policy change, adjusting for differences between groups.

RESULTS

A total of 496 patients (348 pre-policy change; 148 post-policy change) started treatment; excluding loss to follow-up/early discontinuation, SVR rates were 95.4% (309 of 324) pre-policy change and 97.1% (134 of 138) post-policy change. SVR rates did not differ after adjusting for the use of historic HCV regimens and the higher cirrhosis rate in the pre-policy change group compared with the post-policy change group (odds ratio = 0.98; 95% CI, 0.32-3.67).

CONCLUSION

HCV SVR rates were similar before and after removal of the Illinois Medicaid sobriety restriction, regardless of group differences. Results support HCV treatment regardless of documented sobriety to facilitate progress toward HCV elimination.

Predictors of hepatitis C cure among people who inject drugs treated with directly observed therapy supported by peer case managers in Kenya

BACKGROUND & AIMS

Directly observed therapy (DOT) maximizes adherence and minimizes treatment gaps. Peer case managers (PCM) have also shown promise as a component of integrated HCV treatment strategies. DOT and PCM-support have been underexplored, particularly in low- and middle-income countries (LMICs). The objective of this study was to evaluate predictors of sustained virologic response (SVR) among people who inject drugs (PWID) attending medication-assisted treatment (MAT) and needle and syringe programs (NSP) sites in Kenya.

METHODS

We recruited PWID accessing MAT and NSP in Nairobi and Coastal Kenya. PWID were treated with ledipasvir/sofosbuvir using DOT supported by PCMs. We used bivariate and multivariate logistic regression to examine the impact of sociodemographic, behavioral, and clinical factors on SVR.

RESULTS

Among 92 PWID who initiated HCV treatment, 79 (86%) were male with mean age of 36.3 years (SD=±6.5); 38 (41%) were HIV-positive, and 87 (95%) reported injecting drugs in the last 30 days. Just over half of participants were genotype 1a (55%), followed by genotype 4a (41%) and mixed 1a/4a (3%). Most participants, 85 (92%) completed treatment and 79 (86%) achieved SVR. While sociodemographic and behavioral factors including recent injection drug use were not significantly associated with achieving SVR, being fully adherent (p=0.042), number of doses taken (p=0.008) and treatment completion (p= 0.001) were associated with higher odds of achieving SVR.

CONCLUSIONS

DOT with PCM-support was an effective model for HCV treatment among PWID in this LMIC setting. Adherence was the most important driver of SVR suggesting DOT and PCM support can overcome other factors that might limit adherence. Further research is necessary to ascertain the effectiveness of other models of HCV care for PWID in LMICs given NSP and MAT access is variable, and DOT may not be sustainable with limited resources.

Strengthening systems of care for people with or at risk for HIV, HCV and opioid use disorder: a call for enhanced data collection

BACKGROUND

The syndemic between opioid use disorder (OUD), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) results in excessive burdens on the healthcare system. Integrating these siloed systems of care is critical to address all three conditions adequately. In this implementation project, we assessed the data capacity of the health system to measure a cascade of care (COC) across HIV, HCV and OUD services in five states to help guide public health planning.

MATERIALS AND METHODS

Data for this study were gathered from publicly available datasets and reports from government (SAMSHA, CMS, HRSA and CDC) sites. We created, where possible, COCs for HIV, HCV, and OUD spanning population estimate, diagnosis, treatment initiation, treatment retention, and patient outcomes for each of five states in the study.

RESULTS

The process of data collection showed that baseline COCs examining the intersections of OUD, HIV, and HCV cannot be produced and that there are missing data in all states examined. Collection of specific data points is not consistent across all states. States are better at reporting HIV cascades due to federal requirements. Only gross estimates could be made for OUD cascades in all states because data are separated by payer source, leaving no central point of data collection from all sources. Data for HCV were not publicly available.

CONCLUSION

It is difficult to assess the strategies needed or the progress made towards increasing treatment access and decreasing the burden of disease without the ability to construct an accurate baseline. Using integrated COCs with relevant benchmarks can not only guide public health planning, but also provide meaningful targets for intervention.KEY MESSAGESWhile HIV COCs are available for most states at least annually, they are not disaggregated for populations with co-occurring OUD or HCV.Data to calculate HCV COC are not available and data to calculate OUD COC are partially available, but only for specific payers.States do not have systems in place to measure the scope of the syndemic or to identify targets for quality improvement activities.

Reinfection and Risk Behaviors After Treatment of Hepatitis C Virus Infection in Persons Receiving Opioid Agonist Therapy : A Cohort Study

BACKGROUND

Hepatitis C virus (HCV) reinfection after successful treatment may reduce the benefits of cure among people who inject drugs.

OBJECTIVE

To evaluate the rate of HCV reinfection for 3 years after successful treatment among people receiving opioid agonist therapy (OAT).

DESIGN

A 3-year, long-term, extension study of persons enrolled in the CO-STAR (Hepatitis C Patients on Opioid Substitution Therapy Antiviral Response) study (ClinicalTrials.gov: NCT02105688).

SETTING

55 clinical trial sites in 13 countries.

PATIENTS

Aged 18 years and older with chronic HCV infection with genotypes 1, 4, or 6 receiving stable OAT.

INTERVENTION

No treatments were administered.

MEASUREMENTS

Serum samples were assessed for HCV reinfection. Urine drug screening was performed.

RESULTS

Among 296 participants who received treatment, 286 were evaluable for reinfection and 199 were enrolled in the long-term extension study. The rate of HCV reinfection was 1.7 [95% CI, 0.8 to 3.0] per 100 person-years; 604 person-years of follow-up). A higher rate of reinfection was seen among people with recent injecting drug use (1.9 [95% CI, 0.5 to 4.8] per 100 person-years; 212 person-years). Ongoing drug use and injecting drug use were reported by 59% and 21% of participants, respectively, at the 6-month follow-up visit and remained stable during 3 years of follow-up.

LIMITATIONS

Participants were required to be 80% adherent to OAT at baseline and may represent a population with higher stability and lower risk for HCV reinfection. Rate of reinfection may be underestimated because all participants did not continue in the long-term extension study; whether participants who discontinued were at higher risk for reinfection is unknown.

CONCLUSION

Reinfection with HCV was low but was highest in the first 24 weeks after treatment completion and among people with ongoing injecting drug use and needle-syringe sharing.

PRIMARY FUNDING SOURCE

Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc.

Extent and implications of omitted ties on network measures in a longitudinal social network survey of people who use drugs

BACKGROUND

Previous research has revealed under-reporting of personal network members (i.e., alters) in studies involving people who use drugs (PWUD). This analysis (1) characterizes relationships that were more likely to be omitted but later recalled with prompting and (2) identifies network structural characteristics most impacted by these omissions among a sample of PWUD in rural Appalachian Kentucky, an epicenter of the opioid epidemic.

METHODS

Data were collected through longitudinal assessments as part of the Social Networks Among Appalachian People (SNAP) study (2008-2017). Study participants completed interviewer-administered questionnaires that collected social network data via free-listing at baseline and six-month intervals. At visit 5, after free-listing, interviewers prompted participants with the names of previously reported alters. We used modified Poisson regression with generalized estimating equations to identify individual- and relationship-level characteristics associated with an alter being reported only after prompting. We examined the impact of including vs. excluding relationships reported after prompting on local and global sociometric network measures (i.e., betweenness centrality, bridging, density, mean degree, transitivity, cliques, and 2-cores).

RESULTS

Relationships reported only after prompting were more likely to be immediate family (Adjusted Prevalence Ratio [APR]:1.29; 95% Confidence Interval [CI]: 1.03-1.63) and less likely to involve sex (APR:0.54; 95% CI: 0.43-0.67). Considerable differences were observed for participant positional rankings of betweenness centrality and bridging, and differences in network density and average degree pre- and post-prompting were statistically significant.

CONCLUSION

Longitudinal network studies that aim to assess transmission dynamics, information diffusion, or peer influence should consider the effects of omitted relationships.

Collaborative Referral Model to Achieve Hepatitis C Micro-Elimination in Methadone Maintenance Treatment Patients during the COVID-19 Pandemic

Although hepatitis C virus (HCV) prevails in patients receiving methadone maintenance treatment (MMT), most do not receive anti-HCV therapy. This single-center observational study aimed to achieve HCV micro-elimination at an MMT center during the COVID-19 pandemic using a collaborative referral model, which comprised a referral-for-diagnosis stage (January 2020 to August 2020) and an on-site-diagnosis stage (September 2020 to January 2021). A multidisciplinary team was established and all MMT center patients were enrolled. HCV micro-elimination was defined as >90% of HCV-infected patients diagnosed and >80% of HCV-viremic patients treated. A total of 305 MMT patients, including 275 (90.2%) anti-HCV seropositive patients, were enrolled. Among 189 HCV-infected patients needing referral, the accumulative percentage receiving HCV RNA testing increased from 93 (49.2%) at referral-for-diagnosis stage to 168 (88.9%) at on-site-diagnosis stage. Among 138 HCV-viremic patients, the accumulative percentage receiving direct-acting antiviral (DAA) therapy increased from 77 (55.8%) at referral-for-diagnosis stage to 129 (93.5%) at on-site-diagnosis stage. We achieved an HCV RNA testing rate of 92.4% (254/275), an HCV treatment rate of 95.8% (203/212) and a sustained virological response rate of 94.1% (191/203). The collaborative referral model is highly effective in HCV RNA testing and HCV treatment uptake among MMT patients, achieving HCV micro-elimination.

Integrated hepatitis C treatment is associated with improved retention and success in outpatient treatment for opioid use disorder at a private clinic

BACKGROUND

Direct acting antiretrovirals (DAA) are effective for individuals who are infected with chronic hepatitis C virus (HCV), yet many people go without access to these lifesaving treatments.

MATERIALS AND METHODS

We conducted a non-randomized study evaluating treatment data for patients in outpatient treatment for opioid use disorder (OUD) at a private clinic. Patients who were HCV-positive, had been in OUD treatment for at least 4 weeks, and engaged in integrated HCV treatment with DAA (co-located within their treatment for OUD) were compared to patients with HCV who only received OUD treatment. We evaluated HCV cure; OUD medication adherence, treatment utilization and retention; and illicit substance use for those engaged in treatment between 9/2016 and 1/2018.

RESULTS

Seventy-four patients completed integrated HCV-OUD treatment with DAA, with 87.8% achieving cure. Of the 66 who completed treatment and were subsequently evaluated for sustained viral response 98.5% were cured. Patients who received integrated HCV and OUD treatment in our clinic, stayed in OUD treatment longer, demonstrated higher OUD medication adherence, and used less opioids or cocaine compared to HCV-infected patients (n = 572) being treated only for OUD.

DISCUSSION

We have reported on a reproducible intervention that lends itself to outpatient OUD treatment. Analyses demonstrate the potential positive impact HCV treatment has on OUD recovery, including reduction in opioid and cocaine use and increased retention in care.

CONCLUSION

Co-locating HCV treatment with existing OUD treatment is feasible, effective, and demonstrates positive outcomes for the treatment of both conditions.

Treatment of Hepatitis C virus among people who inject drugs at a syringe service program during the COVID-19 response: The potential role of telehealth, medications for opioid use disorder and minimal demands on patients

BACKGROUND

Healthcare delivery was disrupted during the COVID-19 pandemic, requiring minimized in-person contact between patients and clinicians. During the pandemic, people with opioid use disorder (OUD) were not only at elevated risk for COVID-19, but had markedly reduced access to treatment for OUD, Hepatitis C virus (HCV) and HIV due to recommended decreased in-person visits.

METHODS

From March 15-June 15, 2020 at the syringe services program (SSP) in New Haven, Connecticut, USA, a differentiated care model evolved with reduced clinical demands on people who inject drugs (PWID) to ensure screening and treatment for HCV, HIV and OUD, with a focus on HCV treatment. This model involved a single, bundled screening, evaluation, testing (SET) and monitoring strategy for all three conditions, minimal in-person visits, followed by tele-health communication between patients, outreach workers and clinicians. In-person visits occurred only during induction onto methadone and phlebotomy at baseline and phlebotomy 12 weeks post-treatment for HCV to measure sustained virological response (SVR). Patients received supportive texts/calls from outreach workers and clinicians.

RESULTS

Overall, 66 actively injecting PWID, all with OUD, underwent bundled laboratory screening; 35 had chronic HCV infection. Participants were 40 years (mean), mostly white (N = 18) men (N = 28) and 12 were unstably housed. Two were lost to-follow-up and 2 were incarcerated, leaving 31 who started pan-genotypic direct-acting antivirals (DAAs). The mean time from referral to initial phlebotomy and initiation of DAAs was 6.9 and 9.9 days, respectively. Fourteen additional patients were newly started on buprenorphine and 6 started on methadone; three and four, respectively, were on treatment at baseline. Overall, 29 (93.5%) PWID who initiated DAAs achieved SVR; among unstably housed persons the SVR was 83.3%.

CONCLUSIONS

In response to COVID-19, an innovative differentiated care model for PWID at an SSP evolved that included successful co-treatment for HCV, HIV and OUD using a client-centered approach that reduces treatment demands on patients yet supports ongoing access to evidence-based treatments.

Spatiotemporal Phylodynamics of Hepatitis C Among People Who Inject Drugs in India

BACKGROUND AND AIMS

Implementing effective interventions for HCV requires a detailed understanding of local transmission dynamics and geospatial spread. Little is known about HCV phylodynamics, particularly among high-burden populations, such as people who inject drugs (PWID).

APPROACH AND RESULTS

We used 483 HCV sequences and detailed individual-level data from PWID across four Indian cities. Bayesian phylogeographic analyses were used to evaluate transmission hotspots and geospatial diffusion of the virus. Phylogenetic cluster analysis was performed to infer epidemiologic links and factors associated with clustering. A total of 492 HIV sequences were used to draw comparisons within the same population and, in the case of coinfections, evaluate molecular evidence for shared transmission pathways. Overall, 139/483 (28.8%) of HCV sequences clustered with a median cluster size of 3 individuals. Genetically linked participants with HCV were significantly younger and more likely to be infected with HCV subtype 3b as well as to live and inject close to one another. Phylogenetic evidence suggests likely ongoing HCV infection/reinfection with limited support for shared HIV/HCV transmission pathways. Phylogeographic analyses trace historic HCV spread back to Northeastern India and show diffusion patterns consistent with drug trafficking routes.

CONCLUSIONS

This study characterizes HCV phylodynamics among PWID in a low and middle-income country setting. Heterogeneity and recent genetic linkage of HCV across geographically disparate Indian states suggest that targeted interventions could help prevent reimportation of virus through drug trafficking routes.

Injecting network structure determines the most efficient strategy to achieve Hepatitis C elimination in people who inject drugs

Transmission of Hepatitis C (HCV) continues via sharing of injection equipment between people who inject drugs (PWID). Network-based modelling studies have produced conflicting results about whether random treatment is preferable to targeting treatment at PWID with multiple partners. We hypothesise that differences in the modelled injecting network structure produce this heterogeneity. The study aimed to test how changing network structure affects HCV transmission and treatment effects. We created three dynamic injecting network structures connecting 689 PWID (UK-net, AUS-net and USA-net) based on published empirical data. We modelled HCV in the networks and at 5 years compared prevalence of HCV 1) with no treatment, 2) with randomly targeted treatment and 3) with treatment targeted at PWID with the most injecting partnerships (degree-based treatment). HCV prevalence at 5 years without treatment differed significantly between the three networks (UK-net (42.8%) vs. AUS-net (38.2%), p < 0.0001 and vs. USA-net (54.0%), p < 0.0001). In the treatment scenarios UK-net and AUS-net showed a benefit of degree-based treatment with a 5-year prevalence of 1.0% vs. 9.6% p < 0.0001 and 0.15% vs. 0.44%, p < 0.0001. USA-net showed no significant difference (29.3% vs. 29.2%, p = 0.0681). Degree-based treatment was optimised with low prevalence, moderate treatment coverage conditions whereas random treatment was optimised in low treatment coverage, high prevalence conditions. In conclusion, injecting network structure determines the transmission rate of HCV and the most efficient treatment strategy. In real-world injecting network structures, the benefit of targeting HCV treatment at individuals with multiple injecting partnerships may have been underestimated.

Role of direct and indirect social and spatial ties in the diffusion of HIV and HCV among people who inject drugs: a cross-sectional community-based network analysis in New Delhi, India

Background:

People who inject drugs (PWID) account for some of the most explosive human immunodeficiency virus (HIV) and hepatitis C virus (HCV) epidemics globally. While individual drivers of infection are well understood, less is known about network factors, with minimal data beyond direct ties.

Methods:

2512 PWID in New Delhi, India were recruited in 2017–19 using a sociometric network design. Sampling was initiated with 10 indexes who recruited named injection partners (people who they injected with in the prior month). Each recruit then recruited their named injection partners following the same process with cross-network linkages established by biometric data. Participants responded to a survey, including information on injection venues, and provided a blood sample. Factors associated with HIV/HCV infection were identified using logistic regression.

Results:

The median age was 26; 99% were male. Baseline HIV prevalence was 37.0% and 46.8% were actively infected with HCV (HCV RNA positive). The odds of prevalent HIV and active HCV infection decreased with each additional degree of separation from an infected alter (HIV AOR: 0.87; HCV AOR: 0.90) and increased among those who injected at a specific venue (HIV AOR: 1.50; HCV AOR: 1.69) independent of individual-level factors (p<0.001). In addition, sociometric factors, for example, network distance to an infected alter, were statistically significant predictors even when considering immediate egocentric ties.

Conclusions:

These data demonstrate an extremely high burden of HIV and HCV infection and a highly interconnected injection and spatial network structure. Incorporating network and spatial data into the design/implementation of interventions may help interrupt transmission while improving efficiency.

Funding:

National Institute on Drug Abuse and the Johns Hopkins University Center for AIDS Research.

Understanding the social and spatial relationships that connect people is a key element to stop the spread of infectious diseases. These networks are particularly relevant to combat epidemics among populations that are hard to reach with public health interventions. Network-based approaches, for example, can help to stop HIV or hepatitis C from spreading amongst populations that use injectable drugs. Yet how social and geographic connections such as acquaintances, injection partners, or preferred drug use places impact the risk of infection is still poorly mapped out.

To address this question, Clipman et al. focused on people who inject drugs in New Delhi, India, a population heavily impacted by HIV and hepatitis C. Over 2500 people were recruited, each participant inviting their injection partners to also take part. The volunteers answered survey questions, including where they used drugs, and provided a blood sample to be tested.

The results showed that, even after adjusting for individual risk factors, where people used drugs and with whom affected their risk of becoming infected with HIV and hepatitis C. In terms of social ties, the likelihood of HIV and hepatitis C infection decreased by about 13% for each person separating a given individual from an infected person. However, geographical networks also had a major impact. Injecting at a popular location respectively increased the odds of HIV and hepatitis C infection by 50% and 69%. In fact, even if the participant was not using drugs at these specific places, having an injection partner who did was enough to increase the risk for disease: for each person separating an individual from the location, the likelihood of being infected with HIV and hepatitis C decreased by respectively 14% and 10%.

The results by Clipman et al. highlight how the relationships between physical spaces and social networks contribute to the spread of dangerous diseases amongst people who inject drugs. Ultimately, this knowledge may help to shape better public health interventions that would take into account the importance of geographical locations.

Changes in health-related quality of life for HCV-infected people who inject drugs on opioid agonist treatment following sustained virologic response

BACKGROUND

Although efforts to treat hepatitis C virus (HCV) in people who inject drugs (PWID) yield high rates of sustained virologic response (SVR), the relationship between successful HCV treatment and health-related quality of life (HRQOL) among PWID is poorly understood. This study examined HRQOL changes throughout HCV treatment and post-treatment for PWID achieving SVR.

METHODS

Participants included 141 PWID who achieved SVR following HCV treatment onsite at three opioid agonist treatment (OAT) clinics in Bronx, NY. The EQ-5D-3L assesses five health dimensions (mobility, self-care, usual activities, pain/discomfort, anxiety/depression), producing an index of HRQOL ranging from 0-1. EQ-5D-3L was measured at baseline, 4-, 8-, and 12-weeks during treatment and 12- and 24-weeks post-treatment. Linear mixed effects regression models were used to assess changes in the mean EQ-5D-3L index over time.

RESULTS

Mean EQ-5D-3L index baseline was 0.66 (SE=0.02). Whereas over half the population reported no baseline problems with self-care (85.1%), usual activities (56.0%), and mobility (52.5%), at least two-thirds reported problems with pain/discomfort (78.0%) and anxiety/depression (66.0%), with 22.0% and 21.3% reporting extreme problems for pain/discomfort and anxiety/depression, respectively. Twenty-four weeks post-treatment, proportions reporting pain/discomfort and anxiety/depression decreased by 25.7% and 24.0%, respectively. The mean EQ-5D-3L index significantly improved during treatment (p<0.0001), and improvement was sustained following treatment completion, with mean EQ-5D-3L index of 0.77 (SE=0.02) 12-weeks post-SVR.

CONCLUSIONS

HCV treatment led to sustained improvement in HRQOL for PWID on OAT who achieved SVR. Future research is necessary to determine whether improvements in HRQOL can be sustained beyond 12-weeks post-SVR.

Real-World Outcomes in Historically Underserved Patients with Chronic Hepatitis C Infection Treated with Glecaprevir/Pibrentasvir

Introduction

Glecaprevir/pibrentasvir is approved for treating chronic hepatitis C virus (HCV) genotypes (GT) 1–6. We evaluated real-world effectiveness, safety, and patient-reported outcomes of glecaprevir/pibrentasvir in underserved patient populations, focusing on persons who use drugs infected with HCV.

Methods

Data were pooled from nine countries (13 November 2017–31 January 2020). Patients had HCV GT1–6, with or without compensated cirrhosis, with or without prior HCV treatment and received glecaprevir/pibrentasvir consistent with local label at their physician’s discretion. Patients with prior direct-acting antiviral exposure were excluded from efficacy and quality-of-life analyses. The percentage of patients achieving sustained virologic response at post-treatment week 12 (SVR12) was assessed. Mean changes from baseline to SVR12 visit in 36-Item Short-Form Health Survey mental and physical component summary scores were reported. Safety was assessed in patients receiving at least one dose of glecaprevir/pibrentasvir.

Results

Of 2036 patients, 1701 (83.5%) received 8-week glecaprevir/pibrentasvir. In 1684 patients with sufficient follow-up, SVR12 rates were 98.0% (1651/1684) overall, 98.1% (1432/1459) in 8-week treated patients, 97.0% (519/535) in persons who use drugs, and greater than 95% across subgroups. Mean changes from baseline in mental and physical component summary scores were 3.7 and 2.4, respectively. One glecaprevir/pibrentasvir-related serious adverse event was reported; six glecaprevir/pibrentasvir-related adverse events led to discontinuation.

Conclusions

Glecaprevir/pibrentasvir was highly effective, well tolerated, and improved quality of life in HCV-infected persons who use drugs and other underserved patients.

Trial Registration

These multinational post-marketing observational studies are registered with ClinicalTrials.gov, number NCT03303599.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-021-00455-1.

Concurrent Initiation of Hepatitis C and Opioid Use Disorder Treatment in People Who Inject Drugs

BACKGROUND

People who inject drugs have a high prevalence of hepatitis C virus (HCV) and significant disease associated with drug use; however, HCV treatment often occurs in absence of interventions to address opioid use disorder and drug use-related harms. The impact of concurrent initiation of opioid agonist therapy (OAT) on HCV treatment and drug use outcomes is unknown.

METHODS

In this prospective, open-label, observational trial at a harm reduction organization's drop-in center in Washington, DC, 100 patients with chronic HCV infection, opioid use disorder, and ongoing injection drug use were treated with sofosbuvir-velpatasvir for 12-weeks and offered buprenorphine initiation. The primary end point was sustained virologic response (SVR), and secondary end points included uptake of and retention in OAT, change in risk behavior, and determinants of SVR.

RESULTS

Eighty-two patients (82%) achieved SVR, which was not associated with baseline OAT status (P = .33), on-treatment drug use (P >.99), or imperfect daily adherence (P = .35) but was significantly associated with completing 2 or more 28-pill bottles of sofosbuvir-velpatasvir (P < .001) and receiving OAT at week 24 (P = .01). Of 67 patients not already receiving OAT at baseline, 53 (79%) started OAT. At week 24, 68 (68%) patients were receiving OAT. Receipt of OAT was associated with fewer opiate-positive urine drug screens (P = .003), lower human immunodeficiency virus risk-taking behavior scores (P < .001), and lower rates of opioid overdose (P = .04).

CONCLUSIONS

The Novel Model of Hepatitis C Treatment as an Anchor to Prevent HIV, Initiate Opioid Agonist Therapy, and Reduce Risky Behavior study demonstrates high uptake of buprenorphine collocated with HCV treatment, and it shows that concurrent initiation of OAT with HCV treatment can result in high rates of SVR while reducing risks associated with drug use.

CLINICAL TRIALS REGISTRATION

NCT03221309.

Barriers to hepatitis C direct-acting antiviral therapy among HIV/hepatitis C virus-coinfected persons

BACKGROUND AND AIM

Direct-acting antivirals (DAAs) have increased hepatitis C virus (HCV) treatment opportunities for vulnerable HIV/HCV coinfected persons. The aim of this study was to identify the frequency of and potential barriers to DAA prescription in HIV/HCV patients during the first few years of DAA availability in the United States.

METHODS

The AIDS Healthcare Foundation electronic medical record system was queried to identify all HCV viremic HIV-infected patients in care at AIDS Healthcare Foundation Healthcare centers in January 2015-August 2017 and compare characteristics by receipt of a DAA prescription. Multivariate logistic regression analyses were conducted to examine factors associated with DAA prescription.

RESULTS

Of 826 eligible patients, 355 (43%) were prescribed a DAA; among those not prescribed a DAA, 301 (64%) had well-controlled HIV (HIV RNA ≤ 200 copies per mL). In multivariate logistic regression analysis, patients with a history of substance use (odds ratio [OR], 0.51 [95% confidence interval 0.35-0.73]) or on select HIV antiretroviral regimens were less likely to be prescribed a DAA. Those who had well-controlled HIV (OR, 5.03 [3.06-8.27]), CD4 + T cell count >200 cells per mm3 (OR, 1.85 [1.04-3.30]), estimated glomerular filtration rate >60 mL/min/1.73 m2 (OR, 3.32 [1.08-10.15]), or established care prior to January 2015 (OR, 1.57 [1.08-2.29] were more likely to be prescribed a DAA.

CONCLUSIONS

In addition to lack of HIV suppression, select antiretroviral regimens, substance use, and kidney disease appeared to limit DAA prescription in the early interferon-free DAA era. Many were not prescribed DAAs despite HIV suppression. Further research is needed to determine if the observed associations persist today.

Modeling Combination Hepatitis C Virus Treatment and Prevention Strategies in a Network of People Who Inject Drugs in the United States

BACKGROUND

Hepatitis C virus (HCV) treatment as prevention (TasP) strategies can contribute to HCV microelimination, yet complimentary interventions such as opioid agonist therapies (OAT) with methadone or buprenorphine and syringe services programs (SSPs) may improve the prevention impact. This modeling study estimates the impact of scaling up the combination of OAT and SSPs with HCV TasP in a network of people who inject drugs (PWID) in the United States.

METHODS

Using empirical data from Hartford, Connecticut, we deployed a stochastic block model to simulate an injection network of 1574 PWID. We used a susceptible-infected model for HCV and human immunodeficiency virus to evaluate the effectiveness of several HCV TasP strategies, including in combination with OAT and SSP scale-up, over 20 years.

RESULTS

At the highest HCV prevalence (75%), when OAT coverage is increased from 10% to 40%, combined with HCV treatment of 10% per year and SSP scale up to 40%, the time to achieve microelimination is reduced from 18.4 to 11.6 years. At the current HCV prevalence (60%), HCV TasP strategies as low as 10% coverage per year may achieve HCV microelimination within 10 years, with minimal impact from additional OAT scale-up. Strategies based on mass initial HCV treatment (50 per 100 PWID the first year followed by 5 per 100 PWID thereafter) were most effective in settings with HCV prevalence of 60% or lower.

CONCLUSIONS

Scale-up of HCV TasP is the most effective strategy for microelimination of HCV. OAT scale-up, however, scale-up may be synergistic toward achieving microelimination goals when HCV prevalence exceeds 60% and when HCV treatment coverage is 10 per 100 PWID per year or lower.

Age and gender-specific hepatitis C continuum of care and predictors of direct acting antiviral treatment among persons who inject drugs in Seattle, Washington

BACKGROUND

Direct acting antivirals (DAAs) have revolutionized management of hepatitis C virus (HCV), but treatment uptake remains low among persons who inject drugs (PWID). We report the continuum of care for HCV and describe predictors of treatment with DAAs among PWID in Seattle.

METHODS

We analyzed data from the 2018 Seattle area National HIV Behavioral Surveillance (NHBS) survey of PWID. Persons ≥18 years of age who injected drugs in the past year and completed the core NHBS survey, a local survey supplement, and rapid HCV antibody testing were included. Among those who screened HCV antibody positive, we calculated proportions and 95 % confidence intervals for self-reported steps along the HCV care continuum. Multivariable logistic regression was used to calculate the adjusted odds (AOR) of having received DAA therapy.

RESULTS

The sample included 533 PWID, 376 (71 %) of whom tested positive for antibodies to HCV. Among those who were HCV antibody positive, 94 % reported any prior HCV test, 81 % reported a prior confirmatory test, and 68 % reported a prior HCV diagnosis. Of those diagnosed, 26 % had undergone treatment and 18 % had been cured. In a multivariate model, being one year older (AOR 1.05 per year, 1.01-1.08) was predictive of DAA treatment, while homelessness (AOR 0.39, 0.19-0.80) and female gender (AOR 0.36, 0.16-0.78) were associated with a lower odds of DAA therapy.

CONCLUSIONS

Despite widespread HCV testing among PWID in Seattle, treatment uptake remains low in the DAA era. In particular, treatment of women, younger adults and persons living homeless is lagging behind.

Cost-effectiveness of screening and treatment using direct-acting antivirals for chronic Hepatitis C virus in a primary care setting in Karachi, Pakistan

Despite the availability of effective direct-acting antiviral (DAA) treatments for Hepatitis C virus (HCV) infection, many people remain undiagnosed and untreated. We assessed the cost-effectiveness of a Médecins Sans Frontières (MSF) HCV screening and treatment programme within a primary health clinic in Karachi, Pakistan. A health state transition Markov model was developed to estimate the cost-effectiveness of the MSF programme. Programme cost and outcome data were analysed retrospectively. The incremental cost-effectiveness ratio (ICER) was calculated in terms of incremental cost (2016 US$) per disability-adjusted life year (DALY) averted from the provider's perspective over a lifetime horizon. The robustness of the model was evaluated using deterministic and probabilistic sensitivity analyses (PSA). The ICER for implementing testing and treatment compared to no programme was US$450/DALY averted, with 100% of PSA runs falling below the per capita Gross Domestic Product threshold for cost-effective interventions for Pakistan (US$1,422). The ICER increased to US$532/DALY averted assuming national HCV seroprevalence (5.5% versus 33% observed in the intervention). If the cost of liver disease care was included (adapted from resource use data from Cambodia which has similar GDP to Pakistan), the ICER dropped to US$148/DALY, while it became cost-saving if a recently negotiated reduced drug cost of $75/treatment course was assumed (versus $282 in base-case) in addition to cost of liver disease care. In conclusion, screening and DAA treatment for HCV infection are expected to be highly cost-effective in Pakistan, supporting the expansion of similar screening and treatment programmes across Pakistan.

A review of network simulation models of hepatitis C virus and HIV among people who inject drugs

Network modelling is a valuable tool for simulating hepatitis C virus (HCV) and HIV transmission among people who inject drugs (PWID) and assessing the potential impact of treatment and harm-reduction interventions. In this paper, we review literature on network simulation models, highlighting key structural considerations and questions that network models are well suited to address. We describe five approaches (Erdös-Rényi, Stochastic Block, Watts-Strogatz, Barabási-Albert, and Exponential Random Graph Model) used to model partnership formation with emphasis on the strengths of each approach in simulating different features of real-world PWID networks. We also review two important structural considerations when designing or interpreting results from a network simulation study: (1) dynamic vs. static network and (2) injection only vs. both injection and sexual networks. Dynamic network simulations allow partnerships to evolve and disintegrate over time, capturing corresponding shifts in individual and population-level risk behaviour; however, their high level of complexity and reliance on difficult-to-observe data has driven others to develop static network models. Incorporating both sexual and injection partnerships increases model complexity and data demands, but more accurately represents HIV transmission between PWID and their sexual partners who may not also use drugs. Network models add the greatest value when used to investigate how leveraging network structure can maximize the effectiveness of health interventions and optimize investments. For example, network models have shown that features of a given network and epidemic influence whether the greatest community benefit would be achieved by allocating hepatitis C or HIV treatment randomly, versus to those with the most partners. They have also demonstrated the potential for syringe services and "buddy sharing" programs to reduce disease transmission.

Ethical and Practical Issues Associated With the Possibility of Using Controlled Human Infection Trials in Developing a Hepatitis C Virus Vaccine

Despite the existence of established treatments for hepatitis C virus (HCV), more effective means of preventing infection, such as a vaccine, are arguably needed to help reduce substantial global morbidity and mortality. Given the expected challenges of developing such a vaccine among those at heightened risk of infection, controlled human infection studies seem to be a promising potential approach to HCV vaccine development, but they raise substantial ethical and practical concerns. In this article, we describe some of the challenges related to the possibility of using controlled human infection studies to accelerate HCV vaccine development. The related ethical and practical concerns require further deliberation before such studies are planned and implemented.

Targeting the RdRp of Emerging RNA Viruses: The Structure-Based Drug Design Challenge

The RNA-dependent RNA polymerase (RdRp) is an essential enzyme for the viral replication process, catalyzing the viral RNA synthesis using a metal ion-dependent mechanism. In recent years, RdRp has emerged as an optimal target for the development of antiviral drugs, as demonstrated by recent approvals of sofosbuvir and remdesivir against Hepatitis C virus (HCV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), respectively. In this work, we overview the main sequence and structural features of the RdRp of emerging RNA viruses such as Coronaviruses, Flaviviruses, and HCV, as well as inhibition strategies implemented so far. While analyzing the structural information available on the RdRp of emerging RNA viruses, we provide examples of success stories such as for HCV and SARS-CoV-2. In contrast, Flaviviruses' story has raised attention about how the lack of structural details on catalytically-competent or ligand-bound RdRp strongly hampers the application of structure-based drug design, either in repurposing and conventional approaches.

Cost-effectiveness of strategies to improve HCV screening, linkage-to-care and treatment in remand prison settings in England

BACKGROUND

A simplified cascade-of-care may improve screening and treatment uptake among incarcerated individuals. We assessed the cost-effectiveness of traditional and simplified screening and treatment in a London remand prison.

METHODS

Using empirical data from Her Majesty's Prison (HMP) Wormwood Scrubs, London, we designed a decision tree and Markov transition state model using national average data for HCV screening and treatment for the base-case scenario. This compared two alternative strategies; (a) general prison population screening and treatment and (b) prioritising screening and treatment among people who inject drugs (PWID) combined with general prison population screening and treatment. Strategies varied the rates of screening (47%-90%), linkage-to-care (60%-86%) and treatment (21%-85%). Cost, utility and disease transition rates were obtained from existing literature. Outcome measures were as follows: screening, treatment and disease-related costs per admitted individual, quality-adjusted life years (QALYs). Incremental cost-effectiveness ratios (ICERs) were calculated for each intervention. All costs and utilities were discounted at a rate of 3.5% per annum. Both univariate and probabilistic sensitivity analyses have been conducted.

RESULTS

In our cohort of 5239 incarcerated individuals with an estimated chronic HCV prevalence of 2.6%, all strategy ICER values (£3565-10 300) fell below the national willingness to pay threshold (£30 000). Increased successful treatment (7%-54%) was observed by an optimising cascade-of-care. A robust sensitivity analysis identified treatment cost of, QALY for mild liver disease and probability of completing treatment as important factors that impact the ICER value.

CONCLUSION

In our remand setting, optimising adherence to the cascade-of-care is cost-effective. Where universal screening is not practical, a stratified approach focused on intensive screening and treatment of PWID also results in increased treatment uptake and is highly cost-effective.

Continuum of hepatitis C care cascade in prison and following release in the direct-acting antivirals era

BACKGROUND

People with criminal justice involvement contribute remarkably to the rising hepatitis C virus (HCV) burden; however, the continuum of care is a major barrier to prison-based programs. We aimed to evaluate a comprehensive HCV care model in an Iranian provincial prison.

METHODS

Between 2017-2018, in the Karaj Central Prison, newly admitted male inmates received HCV antibody testing and venipuncture for RNA testing (antibody-positive only). Participants with positive RNA underwent direct-acting antiviral (DAA) therapy (Sofosbuvir/Daclatasvir). Sustained virological response was evaluated at 12 weeks post-treatment (SVR12).

RESULTS

Overall, from 3485 participants, 182 (5.2%) and 117 (3.4%) tested positive for HCV antibody and RNA, respectively. Among 116 patients who were eligible for treatment, 24% (n = 28) were released before treatment and 72% (n = 83) initiated DAA therapy, of whom 81% (n = 67/83) completed treatment in prison, and the rest were released. Of total released patients, 68% (n = 30/44) were linked to care in community, and 70% (n = 21/30) completed treatment, including 60% (n = 12/20) and 90% (n = 9/10) among those who were released before and during treatment, respectively. The overall HCV treatment uptake and completion were 89% (n = 103/116) and 85% (n = 88/103), respectively. From people who completed treatment, 43% (n = 38/88) attended for response assessment and all were cured (SVR12 = 100%).

CONCLUSIONS

Integrated HCV care models are highly effective and can be significantly strengthened by post-release interventions. The close collaboration of community and prison healthcare systems is crucial to promote high levels of treatment adherence. Future studies should investigate the predictors of engagement with HCV care following release.

A qualitative study of perceived barriers to hepatitis C care among people who did not attend appointments in the non-urban US South

BACKGROUND

Most people diagnosed with hepatitis C virus (HCV) have not linked to care, despite the availability of safe and effective treatment. We aimed to understand why people diagnosed with HCV have not pursued care in the non-urban Southern United States.

METHODS

We conducted a survey and semi-structured interview with participants referred to an HCV clinic who did not attend an appointment between 2014 and 2018. Our clinic is located in a non-urban region of Virginia at a university hospital. Qualitative data collection was guided by the Health Belief Model (HBM). Data was analyzed using qualitative content analysis to identify key factors influencing patient perceptions regarding HCV and pursuit of care.

RESULTS

Over half of previously referred patients (N = 200) could not be reached by phone. Eleven participants enrolled, including 7 men and 4 women. Based on survey responses, unreliable transportation, unstable housing, substance use, and lack of insurance were common. Participants demonstrated good knowledge of HCV disease, complications, and treatment. On qualitative analysis of semi-structured interviews, final themes emerged from within and between HBM constructs. Emerging themes influencing patient perceptions included (1) structural barriers, (2) stigma, (3) prior experiences of HCV disease and treatment, (4) discordance between the recognized severity of HCV and expected impacts on one's own health, and (5) patient-provider relationship. Substance use was not identified to be a barrier to care.

CONCLUSIONS

Participants perceived individual and structural barriers to linking to care. A strong HCV knowledge base was not sufficient to motivate pursuit of care. Efforts to improve linkage to care must address barriers at multiple levels, and system-level changes are needed. As the majority of previously referred patients could not be contacted by phone, current approaches to patient engagement are not effective for reaching these populations. Expansion of HCV care to primary care settings with an established patient-provider relationship or co-located treatment within substance use treatment programs may serve to increase access to HCV treatment.

Hepatitis C Virus

Hepatitis C virus (HCV) is the most common bloodborne pathogen in the United States, chronically affecting approximately 2.4 million Americans, most of whom are unaware of the infection. Highly effective, well-tolerated therapies are now available with markedly simplified treatment algorithms. Eradication of HCV is a national goal. Increased efforts to extend access to treatment to populations that traditionally are difficult to treat, such as persons who inject drugs, are critical to achieving eradication. Given the magnitude of the disease burden, an increased role of primary care providers in screening, patient stratification, and treatment will be needed.

What is needed to achieve HCV microelimination among HIV-infected populations in Andalusia, Spain: a modeling analysis

BACKGROUND

Scale-up of hepatitis C virus (HCV) treatment for HIV/HCV coinfected individuals is occurring in Spain, the vast majority (> 85%) with a reported history of injecting drug use and a smaller population of co-infected men who have sex with men (MSM). We assess impact of recent treatment scale-up to people living with HIV (PLWH) and implications for achieving the WHO HCV incidence elimination target (80% reduction 2015-2030) among PLWH and overall in Andalusia, Spain, using dynamic modeling.

METHODS

A dynamic transmission model of HCV/HIV coinfection was developed. The model was stratified by people who inject drugs (PWID) and MSM. The PWID component included dynamic HCV transmission from the HCV-monoinfected population. The model was calibrated to Andalusia based on published data and the HERACLES cohort (prospective cohort of HIV/HCV coinfected individuals representing > 99% coinfected individuals in care in Andalusia). From HERACLES, we incorporated HCV treatment among diagnosed PLWH of 10.5%/year from 2004 to 2014, and DAAs at 33%/year from 2015 with 94.8% SVR. We project the impact of current and scaled-up HCV treatment for PLWH on HCV prevalence and incidence among PLWH and overall.

RESULTS

Current treatment rates among PLWH (scaled-up since 2015) could substantially reduce the number of diagnosed coinfected individuals (mean 76% relative reduction from 2015 to 2030), but have little impact on new diagnosed coinfections (12% relative reduction). However, DAA scale-up to PWLH in 2015 would have minimal future impact on new diagnosed coinfections (mean 9% relative decrease from 2015 to 2030). Similarly, new cases of HCV would only reduce by a mean relative 29% among all PWID and MSM due to ongoing infection/reinfection. Diagnosing/treating all PLWH annually from 2020 would increase the number of new HCV infections among PWLH by 28% and reduce the number of new HCV infections by 39% among the broader population by 2030.

CONCLUSION

Targeted scale-up of HCV treatment to PLWH can dramatically reduce prevalence among this group but will likely have little impact on the annual number of newly diagnosed HIV/HCV coinfections. HCV microelimination efforts among PWLH in Andalusia and settings where a large proportion of PLWH have a history of injecting drug use will require scaled-up HCV diagnosis and treatment among PLWH and the broader population at risk.

2020 Taiwan consensus statement on the management of hepatitis C: Part (II) special populations

Hepatitis C virus (HCV) infection is a silent killer that leads to rapid progression of liver cirrhosis and hepatocellular carcinoma (HCC). High prevalence of HCV infection has been reported in Taiwan, especially in high-risk populations including people who inject drugs (PWID) and patients requiring dialysis. Besides, certain populations merit special considerations due to suboptimal outcome, potential drug-drug interaction, or possible side effect. Therefore, in the second part of this 2-part consensus, the Taiwan Association for the Study of the Liver (TASL) proposes the treatment recommendations for the special population in order to serve as guidance to optimizing the outcome in the direct-acting antiviral (DAA) era. Special populations include patients with acute or recent HCV infection, previous DAA failure, chronic kidney disease, decompensated cirrhosis, HCC, liver and other solid organ transplantations, receiving an HCV viremic organ, hepatitis B virus (HBV) and HCV dual infection, HCV and human immunodeficiency virus (HIV) coinfection, active tuberculosis infection, PWID, bleeding disorders and hemoglobinopathies, children and adolescents, and pregnancy. Moreover, future perspectives regarding the management of hepatitis C are also discussed and summarized in this consensus statement.

Identifying and managing infectious disease syndemics in patients with HIV

PURPOSE OF REVIEW

We will present recent articles focusing on HIV synergistic interactions with other sexually transmitted infections, tuberculosis, and hepatitis, as well as recent advances in the study of social and behavioral determinants that facilitate this clustering of infectious disease. For each synergistic interaction, we highlight evidence-based interventions that clinicians and policymakers should consider to tackle HIV and infectious disease syndemics.

RECENT FINDINGS

Significant advances in understanding the behavioral and structural determinants of HIV and other infectious disease synergisms have been made in the past years. Intervention strategies based on these new models have also been developed. It is now well understood that treating infectious disease syndemics will require a multidisciplinary and multipronged approach.

SUMMARY

HIV is synergistic with multiple other infectious diseases because the risk behaviors that lead to HIV acquisition may be similar to the other infections. The influence of HIV on the other infection may be due to immunosuppression associated with disease progression resulting in increased susceptibility (e.g., HIV and tuberculosis), especially when patients are not virologically suppressed using antiretroviral therapy. In reverse, another infectious disease may, when not treated, influence HIV disease progression. Social/structural determinants like homelessness, mass incarceration, and structural discrimination precipitate psychiatric comorbidity, substance use, and risky sex behavior which lead to the spread and co-occurrence of infectious disease.

Addressing Hepatitis C in the American Incarcerated Population: Strategies for Nationwide Elimination

PURPOSE OF REVIEW

The prevalence of Hepatitis C virus (HCV) in the US incarcerated population is disproportionately high, and when inmates with infection are released back into the general population, they play a substantial role in the spread of disease. This review provides support for targeting the jail/prison population to eliminate HCV in the general population. It will also summarize various screening/treatment models to curtail the burden of disease behind and beyond bars.

RECENT FINDINGS

Transitioning from risk-based testing to opt-out testing in prisons/jails would be cost-effective through greater identification of cases and treatment to prevent complications from cirrhosis. Other innovative strategies, such as the nominal pricing mechanism or the "Netflix" DAA subscription model, have the potential to be cost-effective and to increase access to treatment. Addressing HCV in the incarcerated population is a strategy to bring the US closer to successfully eradicating the epidemic. Such findings should incentivize policymakers to implement care models that target this population.

Progress Toward Hepatitis C Virus Elimination: Therapy and Implementation

The World Health Organization has called for the elimination of hepatitis C virus (HCV) as a public health threat by 2030. Highly effective direct-acting antiviral agents provide the therapeutic tools required for elimination. In the absence of a vaccine, HCV elimination will require enhanced primary prevention and an increase in the proportions of people diagnosed and treated. Given that globally only 20% of people with chronic HCV are diagnosed, and around 5% have initiated HCV treatment, the task ahead is enormous. But, global public health needs optimism, and countries currently on track for HCV elimination provide a pathway forward.

Eliminating Hepatitis C Virus Among Human Immunodeficiency Virus-Infected Men Who Have Sex With Men in Berlin: A Modeling Analysis

BACKGROUND

Despite high hepatitis C virus (HCV) treatment rates, HCV incidence among human immunodeficiency virus (HIV)-infected men who have sex with men (HIV-infected MSM) in Germany rose before HCV direct-acting antivirals (DAAs). We model what intervention can achieve the World Health Organization (WHO) elimination target of an 80% reduction in HCV incidence by 2030 among HIV-infected MSM in Berlin.

METHODS

An HCV transmission model among HIV-diagnosed MSM was calibrated to Berlin (rising HCV incidence and high rates of HCV testing and treatment). We modeled the HCV incidence among HIV-diagnosed MSM in Berlin until 2030 (relative to 2015 WHO baseline) under scenarios of DAA scale-up with or without behavior change (among HIV-diagnosed MSM and/or all MSM).

RESULTS

Continuing current treatment rates will marginally reduce the HCV incidence among HIV-diagnosed MSM in Berlin by 2030. Scaling up DAA treatment rates, beginning in 2018, to 100% of newly diagnosed HCV infections within 3 months of diagnosis and 25% each year of previously diagnosed and untreated HCV infections could reduce the HCV incidence by 61% (95% confidence interval, 55.4%-66.7%) by 2030. The WHO target would likely be achieved by combining DAA scale-up with a 40% reduction in HCV transmission among HIV-diagnosed MSM and a 20% reduction among HIV-undiagnosed or HIV-uninfected MSM.

DISCUSSION

HCV elimination among HIV-infected MSM in Berlin likely requires combining DAA scale-up with moderately effective behavioral interventions to reduce risk among all MSM.

"Everybody living with a chronic disease is entitled to be cured": Challenges and opportunities in scaling up access to direct-acting antiviral hepatitis C virus treatment among people who inject drugs

BACKGROUND

Recent advances in the safety, tolerability, and efficacy of hepatitis C virus (HCV) treatments have led to the introduction of policy changes that include, in some settings, universal coverage of direct-acting antiviral (DAA) treatment for people living with HCV. However, people who inject drugs (PWID), a population with disproportionately high rates of HCV, often experience significant social and structural barriers to care, including when seeking treatment and care for blood-borne viruses. The objective of this study is to identify implementation challenges and opportunities for improving HCV-related care and scaling up DAA treatment for PWID living with HCV in a setting with universal DAA coverage since 2018.

METHODS

Informed by a critical interpretive framework, this study thematically analyzes data from in-depth, semi-structured interviews conducted between October 2018 and February 2019 with a purposive sample of 15 expert stakeholders (e.g., clinicians, community-based organization representatives, policy makers) related to HCV care or research in British Columbia, Canada.

RESULTS

Our analysis revealed two key thematics: First, participants described existing challenges for scaling up DAA treatment, including how contextual factors (e.g., housing, stigma) restrict opportunities for PWID to engage in care. Participants also described how strained and compartmentalized health services are onerous to navigate for patients. Second, participants described opportunities for improving HCV-related care through various structural interventions (e.g., improved housing, decriminalization of substance use), and enhanced and more accessible models of care (e.g., decentralized, integrated, outreach-focused, and peer- and nurse-led services).

CONCLUSIONS

These findings emphasize that several key service delivery and system-level adaptations are required in order to equitably scale up access of DAAs to PWID living with HCV, including policies and programs that are responsive to socio-structural determinants of health.

Estimation and correction of bias in network simulations based on respondent-driven sampling data

Respondent-driven sampling (RDS) is widely used for collecting data on hard-to-reach populations, including information about the structure of the networks connecting the individuals. Characterizing network features can be important for designing and evaluating health programs, particularly those that involve infectious disease transmission. While the validity of population proportions estimated from RDS-based datasets has been well studied, little is known about potential biases in inference about network structure from RDS. We developed a mathematical and statistical platform to simulate network structures with exponential random graph models, and to mimic the data generation mechanisms produced by RDS. We used this framework to characterize biases in three important network statistics – density/mean degree, homophily, and transitivity. Generalized linear models were used to predict the network statistics of the original network from the network statistics of the sample network and observable sample design features. We found that RDS may introduce significant biases in the estimation of density/mean degree and transitivity, and may exaggerate homophily when preferential recruitment occurs. Adjustments to network-generating statistics derived from the prediction models could substantially improve validity of simulated networks in terms of density, and could reduce bias in replicating mean degree, homophily, and transitivity from the original network.

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.

Prioritising Hepatitis C treatment in people with multiple injecting partners maximises prevention: A real-world network study

OBJECTIVE

To describe an injecting network of PWID living in an isolated community on the Isle of Wight (UK) and the results of a agent-based simulation, testing the effect of Hepatitis C (HCV) treatment on transmission.

METHOD

People who inject drugs (PWID) were identified via respondent driven sampling and recruited to a network and bio-behavioural survey. The injecting network they described formed the baseline population and potential transmission pathways in an agent-based simulation of HCV transmission and the effects of treatment over 12 months.

RESULTS

On average each PWID had 2.6 injecting partners (range 0-14) and 137 were connected into a single component. HCV in the network was associated with a higher proportion of positive injecting partners (p = 0.003) and increasing age (p = 0.011). The treatment of well-connected PWID led to significantly fewer new infections of HCV than treating at random (10 vs. 7, p<0.001). In all scenarios less than one individual was re-infected.

CONCLUSION

In our model the preferential treatment of well-connected PWID maximised treatment as prevention. In the real-world setting, targeting treatment to actively injecting PWID, with multiple injecting partners may therefore represent the most efficient elimination strategy for HCV.

MULTI-OBJECTIVE MODEL EXPLORATION OF HEPATITIS C ELIMINATION IN AN AGENT-BASED MODEL OF PEOPLE WHO INJECT DRUGS

Hepatitis C (HCV) is a leading cause of chronic liver disease and mortality worldwide and persons who inject drugs (PWID) are at the highest risk for acquiring and transmitting HCV infection. We developed an agent-based model (ABM) to identify and optimize direct-acting antiviral (DAA) therapy scale-up and treatment strategies for achieving the World Health Organization (WHO) goals of HCV elimination by the year 2030. While DAA is highly efficacious, it is also expensive, and therefore intervention strategies should balance the goals of elimination and the cost of the intervention. Here we present and compare two methods for finding PWID treatment enrollment strategies by conducting a standard model parameter sweep and compare the results to an evolutionary multi-objective optimization algorithm. The evolutionary approach provides a pareto-optimal set of solutions that minimizes treatment costs and incidence rates.

Mathematical modeling of hepatitis c virus (HCV) prevention among people who inject drugs: A review of the literature and insights for elimination strategies

In 2016, the World Health Organization issued global elimination targets for hepatitis C virus (HCV), including an 80% reduction in HCV incidence by 2030. The vast majority of new HCV infections occur among people who inject drugs (PWID), and as such elimination strategies require particular focus on this population. As governments urgently require guidance on how to achieve elimination among PWID, mathematical modeling can provide critical information on the level and targeting of intervention are required. In this paper we review the epidemic modeling literature on HCV transmission and prevention among PWID, highlight main differences in mathematical formulation, and discuss key insights provided by these models in terms of achieving WHO elimination targets among PWID. Overall, the vast majority of modeling studies utilized a deterministic compartmental susceptible-infected-susceptible structure, with select studies utilizing individual-based network transmission models. In general, these studies found that harm reduction alone is unlikely to achieve elimination targets among PWID. However, modeling indicates elimination is achievable in a wide variety of epidemic settings with harm reduction scale-up combined with modest levels of HCV treatment for PWID. Unfortunately, current levels of testing and treatment are generally insufficient to achieve elimination in most settings, and require further scale-up. Additionally, network-based treatment strategies as well as prison-based treatment and harm reduction provision could provide important additional population benefits. Overall, epidemic modeling has and continues to play a critical role in informing HCV elimination strategies worldwide.

Hepatitis C

Hepatitis C is a global health problem, and an estimated 71·1 million individuals are chronically infected with hepatitis C virus (HCV). The global incidence of HCV was 23·7 cases per 100 000 population (95% uncertainty interval 21·3-28·7) in 2015, with an estimated 1·75 million new HCV infections diagnosed in 2015. Globally, the most common infections are with HCV genotypes 1 (44% of cases), 3 (25% of cases), and 4 (15% of cases). HCV transmission is most commonly associated with direct percutaneous exposure to blood, via blood transfusions, health-care-related injections, and injecting drug use. Key high-risk populations include people who inject drugs, men who have sex with men, and prisoners. Approximately 10-20% of individuals who are chronically infected with HCV develop complications, such as cirrhosis, liver failure, and hepatocellular carcinoma over a period of 20-30 years. Direct-acting antiviral therapy is now curative, but it is estimated that only 20% of individuals with hepatitis C know their diagnosis, and only 15% of those with known hepatitis C have been treated. Increased diagnosis and linkage to care through universal access to affordable point-of-care diagnostics and pangenotypic direct-acting antiviral therapy is essential to achieve the WHO 2030 elimination targets.

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.

Scaling Up Hepatitis C Prevention and Treatment Interventions for Achieving Elimination in the United States: A Rural and Urban Comparison

In the United States, hepatitis C virus (HCV) transmission is rising among people who inject drugs (PWID). Many regions have insufficient prevention intervention coverage. Using modeling, we investigated the impact of scaling up prevention and treatment interventions on HCV transmission among PWID in Perry County, Kentucky, and San Francisco, California, where HCV seroprevalence among PWID is >50%. A greater proportion of PWID access medication-assisted treatment (MAT) or syringe service programs (SSP) in urban San Francisco (established community) than in rural Perry County (young, expanding community). We modeled the proportion of HCV-infected PWID needing HCV treatment annually to reduce HCV incidence by 90% by 2030, with and without MAT scale-up (50% coverage, both settings) and SSP scale-up (Perry County only) from 2017. With current MAT and SSP coverage during 2017-2030, HCV incidence would increase in Perry County (from 21.3 to 22.6 per 100 person-years) and decrease in San Francisco (from 12.9 to 11.9 per 100 person-years). With concurrent MAT and SSP scale-up, 5% per year of HCV-infected PWID would need HCV treatment in Perry County to achieve incidence targets-13% per year without MAT and SSP scale-up. In San Francisco, a similar proportion would need HCV treatment (10% per year) irrespective of MAT scale-up. Reaching the same impact by 2025 would require increases in treatment rates of 45%-82%. Achievable provision of HCV treatment, alongside MAT and SSP scale-up (Perry County) and MAT scale-up (San Francisco), could reduce HCV incidence.

Current and forthcoming perspectives in linkage to care of hepatitis C virus infection: Assessment of an Italian focus group

Hepatitis C virus (HCV) remains a significant public health problem and is one of the major causes of chronic liver disease worldwide. In recent years many new tools to facilitate widespread HCV screening and new therapeutic options with excellent efficacy and tolerability profiles and cost lowering policies have become available. To fully utilise these new tools, the link between local and specialist centres for the management of HCV infection must be reinforced. In order to GAIN further insight into these aspects, with a particular focus on the Italian scenario, a group of experts met to discuss relevant aspects and open issues on chronic HCV. As a summary of that meeting, the following aspects are here overviewed: (i) global situation of HCV; (ii) screening, diagnosis and indications for the treatment of HCV; (iii) the Italian situation of HCV referrals; (iv) 'hard to reach' patients; (v) treatment of HCV with extrahepatic manifestations; (vi) treatment of patients with advanced cirrhosis. It is the intention of the expert panel to further promote widespread screening and eradication policies that should be accompanied by greater interaction, by attempting to involve all healthcare providers in an organised process to facilitate linkage to care of patients with HCV infections.