Are Interferon-Free Direct-Acting Antivirals for the Treatment of HCV Enough to Control the Epidemic among People Who Inject Drugs?

Negative impact of HIV infection on broad-spectrum anti-HCV neutralizing antibody titers in HCV-infected patients with advanced HCV-related cirrhosis

OBJECTIVES

The current study aimed to assess the impact of HIV on the production of anti-HCV antibodies in HCV-infected individuals with advanced HCV-related cirrhosis before and 36 weeks after the sustained virological response (SVR) induced by direct-acting antivirals (DAAs) therapy.

METHODS

Prospective study on 62 patients (50 HIV/HCV-coinfected and 12 HCV-monoinfected). Plasma anti-E2 and HCV-nAbs were determined respectively by ELISA and microneutralization assays.

RESULTS

At baseline, the HCV-group had higher anti-E2 levels against Gt1a (p = 0.012), Gt1b (p = 0.023), and Gt4a (p = 0.005) than the HIV/HCV-group. After SVR, anti-E2 titers against Gt1a (p < 0.001), Gt1b (p = 0.001), and Gt4a (p = 0.042) were also higher in the HCV-group than HIV/HCV-group. At 36 weeks post-SVR, plasma anti-E2 titers decreased between 1.3 and 1.9-fold in the HIV/HCV-group (p < 0.001) and between 1.5 and 1.8-fold in the HCV-group (p ≤ 0.001). At baseline, the HCV-group had higher titers of HCV-nAbs against Gt1a (p = 0.022), Gt1b (p = 0.002), Gt2a (p < 0.001), and Gt4a (p < 0.001) than the HIV/HCV-group. After SVR, HCV-nAbs titers against Gt1a (p = 0.014), Gt1b (p < 0.001), Gt2a (p = 0.002), and Gt4a (p = 0.004) were also higher in the HCV-group. At 36 weeks post-SVR, HCV-nAbs decreased between 2.6 and 4.1-fold in the HIV/HCV-group (p < 0.001) and between 1.9 and 4.0-fold in the HCV-group (p ≤ 0.001).

CONCLUSIONS

HIV/HCV-coinfected patients produced lower levels of broad-spectrum anti-HCV antibodies than HCV-monoinfected patients.

M2HepPrEP: study protocol for a multi-site multi-setting randomized controlled trial of integrated HIV prevention and HCV care for PWID

Background

Opioid use is escalating in North America and comes with a multitude of health consequences, including HIV and hepatitis C virus (HCV) outbreaks among persons who inject drugs (PWID). HIV pre-exposure prophylaxis (PrEP) and HCV treatment regimens have transformative potential to address these co-occurring epidemics. Evaluation of innovative multi-modal approaches, integrating harm reduction, opioid agonist therapy (OAT), PrEP, and HCV treatment is required. The aim of this study is to assess the effectiveness of an on-site integrated care model where delivery of PrEP and HCV treatment for PWID takes places at syringe service programs (SSP) and OAT programs compared with referring PWID to clinical services in the community through a patient navigation model and to examine how structural factors interact with HIV prevention adherence and HCV treatment outcomes.

Methods

The Miami-Montreal Hepatitis C and Pre-Exposure Prophylaxis trial (M²HepPrEP) is an open-label, multi-site, multi-center, randomized, controlled, superiority trial with two parallel treatment arms. A total of 500 persons who injected drugs in the prior 6 months and are eligible for PrEP will be recruited in OAT clinics and SSP in Miami, FL, and Montréal, Québec. Participants will be randomized to either on-site care, with adherence counseling, or referral to off-site clinics assisted by a patient navigator. PrEP will be offered to all participants and HCV treatment to those HCV-infected. Co-primary endpoints will be (1) adherence to pre-exposure prophylaxis medication at 6 months post-randomization and (2) HCV sustained virological response (SVR) 12 weeks post-treatment completion among participants who were randomized within the HCV stratum. Up to 100 participants will be invited to participate in a semi-structured interview regarding perceptions of adherence barriers and facilitators, after their 6-month assessment. A simulation model-based cost-effectiveness analysis will be performed to determine the comparative value of the strategies being evaluated.

Discussion

The results of this study have the potential to demonstrate the effectiveness and cost-effectiveness of offering PrEP and HCV treatment in healthcare venues frequently attended by PWID. Testing the intervention in two urban centers with high disease burden among PWID, but with different healthcare system dynamics, will increase generalizability of findings.

Trial registration

Clinicaltrials.gov NCT03981445. Trial registry name: Integrated HIV Prevention and HCV Care for PWID (M2HepPrEP). Registration date: June 10, 201.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06085-3.

Health programmes and services addressing the prevention and management of infectious diseases in people who inject drugs in Canada: a systematic integrative review

OBJECTIVES

People who inject drugs (PWID) experience a high burden of injection drug use-related infectious disease and challenges in accessing adequate care. This study sought to identify programmes and services in Canada addressing the prevention and management of infectious disease in PWID.

DESIGN

This study employed a systematic integrative review methodology. Electronic databases (PubMed, CINAHL and Web of Science Core Collection) and relevant websites were searched for literature published between 2008 and 2019 (last search date was 6 June 2019). Eligible articles and documents were required to address injection or intravenous drug use and health programmes or services relating to the prevention or management of infectious diseases in Canada.

RESULTS

This study identified 1607 unique articles and 97 were included in this study. The health programmes and services identified included testing and management of HIV and hepatitis C virus (n=27), supervised injection facilities (n=19), medication treatment for opioid use disorder (n=12), integrated infectious disease and addiction programmes (n=10), needle exchange programmes (n=9), harm reduction strategies broadly (n=6), mobile care initiatives (n=5), peer-delivered services (n=3), management of IDU-related bacterial infections (n=2) and others (n=4). Key implications for policy, practice and future research were identified based on the results of the included studies, which include addressing individual and systemic factors that impede care, furthering evaluation of programmes and the need to provide comprehensive care to PWID, involving medical care, social support and harm reduction.

CONCLUSIONS

These results demonstrate the need for expanded services across a variety of settings and populations. Our study emphasises the importance of addressing social and structural factors that impede infectious disease care for PWID. Further research is needed to improve evaluation of health programmes and services and contextual factors surrounding accessing services or returning to care.

PROSPERO REGISTRATION NUMBER

CRD42020142947.

HCV treatment barriers among HIV/HCV co-infected patients in the US: a qualitative study to understand low uptake among marginalized populations in the DAA era

BACKGROUND

Well-tolerated, highly effective HCV treatment, known as direct-acting antivirals (DAAs), is now recommended for all people living with HCV, providing the tools for HCV elimination. We sought to understand treatment barriers among low-income HIV/HCV coinfected patients and providers with the goal of increasing uptake.

METHODS

In 2014, we conducted 26 interviews with HIV/HCV co-infected patients and providers from a San Francisco clinic serving underinsured and publically-insured persons to explore barriers impacting treatment engagement and completion. Interview transcripts were coded, and a thematic analysis was conducted to identify emerging patterns.

RESULTS

Conditions of poverty-specifically, meeting basic needs for food, shelter, and safety-undermined patient perceptions of self-efficacy to successfully complete HCV treatment programs. While patient participants expressed interest in HCV treatment, the perceived burden of taking daily medications without strong social support was an added challenge. This need for support contradicted provider assumptions that, due to the shorter-course regimens, support is unnecessary in the DAA era.

CONCLUSIONS

Interferon-free treatments alone are not sufficient to overcome social-structural barriers to HCV treatment and care among low-income HIV/HCV co-infected patients. Support for patients with unmet social needs may facilitate treatment initiation and completion, particularly among those in challenging socioeconomic situations.

Risk behaviours of homeless people who inject drugs during an outbreak of hepatitis C, Northern Ireland, 2016-2017

From July to August 2016, 4 homeless people who injected drugs (PWID) with acute or recent hepatitis C virus (HCV) infection were reported in Belfast. A multidisciplinary team including public health, homeless and addiction services undertook an investigation to identify risk behaviours and interrupt transmission chains. Recent HCV cases were defined as negative test within the previous year, or reported injecting for less than 1 year; acute cases had tested negative within the previous 6 months. Contacts in the injecting networks of cases were identified for testing. We undertook a cross-sectional survey using structured questionnaires to elicit risk behaviours for PWID and compare behaviours between self-reported hepatitis C positive and negative subjects. During the outbreak investigation until December 2017, 156 PWID were tested and 45 (29%) cases identified, including 7 (16%) recent and 13 (29%) acute infections. 68 PWID, including 12 cases, were interviewed. All respondents reported using heroin, with 76% injecting once or more daily. Sharing was reported for spoons (58%) and filters (53%), but also needles (27%) and syringes (29%). Hepatitis C positive individuals had higher odds to be injecting in public toilets (AOR 17, 95% CI 0.71-400, P < .05) when compared with hepatitis C negative individuals. Hepatitis C positive individuals were more likely to inject in public spaces, but all respondents indicated concerning risk behaviours. We recommend active surveillance with ongoing testing, expanding existing harm reduction programmes and access to bespoke services.

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.

Transitioning from interferon-based to direct antiviral treatment options: A potential shift in barriers and facilitators of treatment initiation among people who use drugs?

BACKGROUND

Multiple barriers for accessing hepatitis C virus (HCV) treatment were identified during the interferon-based (IFN) treatment era for people who inject drugs (PWID). Whether these barriers persist since the introduction of IFN-free direct-acting antiviral (DAA) agents in Canada remains to be documented. This study examined temporal trends in HCV treatment initiation and associated factors during the transition from INF-based to all-oral DAA regimens.

METHODS

The study population was drawn from a prospective cohort of PWID in Montreal, Canada. At three-month/one-year intervals between 2011 and 2017, participants with chronic HCV infection completed an interviewer-administered questionnaire on socio-demographic characteristics, drug use and health service utilisation, including HCV treatment. Time-updated Cox multivariate regression models, stratified by DAA + INF (2011-2013) and all-oral DAA (2014-2017) availability periods, were conducted to examine associations between time to HCV treatment initiation and associated barriers and facilitators.

RESULTS

Of 308 participants (85% male, median age 42 [IQR: 33, 50]), 80 (26%) initiated HCV treatment during 915 person-years (PY). Incidence rates increased from 1.6 /100 PY (95%CI:0.9-2.6) in 2011 to 12.7 (10.6-15.1) in 2017 (p-trend = 0.0012). In multivariate analyses, visiting a primary care physician (2011-2013: aHR = 3.63[1.21-10.9]; 2014-2017: 2.52[1.10-5.77]) and frequent injection (0.23[0.05-0.99] and 0.49[0.24-0.99]) were consistently associated with treatment initiation. Participants aged >40 (2.27[1.24-4.13]), receiving opioid agonist therapy (OAT) (2.17[1.19-3.94]), and reporting prior HCV treatment (3.00[1.75-5.15]) were more likely to initiate treatment in the all-oral DAA period.

CONCLUSION

Treatment initiation increased between 2011 and 2017, but still remains low among PWID. Primary care visiting was a key facilitator regardless of the period, while engagement in OAT and health services, indicated by prior HCV treatment, increased the likelihood of treatment initiation in the DAA era. These findings suggest that access to health services is essential but not enough to scale up treatment in this population.

Hepatitis C transmission in young people who inject drugs: Insights using a dynamic model informed by state public health surveillance

Increasing injection of heroin and prescription opioids have led to increases in the incidence of hepatitis C virus (HCV) infections in US young adults since the early 2000s. How best to interrupt transmission and decrease HCV prevalence in young people who inject drugs (PWID) is uncertain. We developed an age-stratified ordinary differential equation HCV transmission model of PWID aged 15-64, which we fit to Michigan HCV surveillance data among young PWID aged 15-29. We used Latin hypercube sampling to fit to data under 10,000 plausible model parameterizations. We used the best-fitting 10% of simulations to predict the potential impact of primary (reducing injection initiation), secondary (increasing cessation, reducing injection partners, or reducing injection drug use relapse), and tertiary (HCV treatment) interventions (over the period 2017-2030) on acute and chronic HCV cases by the year 2030. Treating 3 per 100 current and former PWID per year could reduce chronic HCV by 27.3% (range: 18.7-30.3%) and acute HCV by 23.6% (range: 6.7-29.5%) by 2030 among PWID aged 15-29 if 90% are cured (i.e. achieved sustained virologic response [SVR] to treatment). Reducing the number of syringe sharing partners per year by 10% was predicted to reduce chronic HCV by 15.7% (range: 9.4-23.8%) and acute cases by 21.4% (range: 14.2-32.3%) among PWID aged 15-29 by 2030. In simulations of combinations of interventions, reducing injection initiation, syringe sharing, and relapse rates each by 10% while increasing cessation rates by 10% predicted a 27.7% (range: 18.0-39.7%) reduction in chronic HCV and a 38.4% (range: 28.3-53.3%) reduction in acute HCV. Our results highlight the need for HCV treatment among both current and former PWID and the scale up of both primary and secondary interventions to concurrently reduce HCV prevalence and incidence in Michigan.

Accelerating the elimination of viral hepatitis: a Lancet Gastroenterology & Hepatology Commission

Viral hepatitis is a major public health threat and a leading cause of death worldwide. Annual mortality from viral hepatitis is similar to that of other major infectious diseases such as HIV and tuberculosis. Highly effective prevention measures and treatments have made the global elimination of viral hepatitis a realistic goal, endorsed by all WHO member states. Ambitious targets call for a global reduction in hepatitis-related mortality of 65% and a 90% reduction in new infections by 2030. This Commission draws together a wide range of expertise to appraise the current global situation and to identify priorities globally, regionally, and nationally needed to accelerate progress. We identify 20 heavily burdened countries that account for over 75% of the global burden of viral hepatitis. Key recommendations include a greater focus on national progress towards elimination with support given, if necessary, through innovative financing measures to ensure elimination programmes are fully funded by 2020. In addition to further measures to improve access to vaccination and treatment, greater attention needs to be paid to access to affordable, high-quality diagnostics if testing is to reach the levels needed to achieve elimination goals. Simplified, decentralised models of care removing requirements for specialised prescribing will be required to reach those in need, together with sustained efforts to tackle stigma and discrimination. We identify key examples of the progress that has already been made in many countries throughout the world, demonstrating that sustained and coordinated efforts can be successful in achieving the WHO elimination goals.

Understanding and Addressing Hepatitis C Virus Reinfection Among Men Who Have Sex with Men

Hepatitis C virus reinfection rates among men who have sex with men are high. Factors associated with infection point to varied sexual and drug-related risks that could be targeted for interventions to prevent infection/reinfection. Modeling indicates that tackling increasing incidence and high reinfection rates requires high levels of hepatitis C virus treatment combined with behavioral interventions. Enhanced testing strategies and prompt retreating of reinfection may be required to promptly diagnosed reinfections. Behavioral interventions studies addressing reinfection are required. Other interventions include traditional harm reduction interventions, adapted behavioral interventions, and interventions to prevent harms related to ChemSex and other risk factors.

HCV seroconversion in a cohort of people who use drugs followed in a mobile harm reduction unit in Madrid: Breaking barriers for HCV elimination

Background and aims

Harm reduction strategies have been shown to decrease the incidence of human immunodeficiency virus (HIV) infection in people who inject drugs (PWID), but the results have been inconsistent when it comes to prevention of hepatitis C virus (HCV) infection. We aimed to examine the rate of HCV seroconversion among people who use drugs (PWUD) followed at a mobile harm reduction unit (MHRU) to evaluate if a low-threshold methadone substitution program (LTMSP) is associated with a low HCV seroconversion rate and subsequently identify barriers for elimination.

Materials and methods

A cohort of PWUD have been followed at a MRHU in Madrid between 2013 and 2016. Individuals who were negative for HCV antibodies at baseline and who had at least one retest for HCV antibodies were eligible. Kaplan-Meier methods were employed to estimate the global incidence density.

Results

During the study period, 946 PWUD were screened for HCV at least once. At baseline 127 PWUD were negative for HCV antibodies and had at least one follow-up HCV antibodies test. The baseline HCV prevalence was 33%. After a median 0.89 (IQR 0.3–1.5) years of follow-up and 135 person-years of risk for HCV infection, 28 subjects seroconverted. The incidence density for HCV seroconversion for this sample was 20.7 cases (95% CI: 14.3–29.7) per 100 person-years. Injecting drugs in the last year was strongly associated to HCV seroconversion (AHR 15.5, 95%CI 4.3–55.8, p < 0.001). Methadone status was not associated to HCV seroconversion.

Conclusions

A high incidence of HCV infection was found among PWUD at a MHRU in Madrid. In this setting opiate substitutive treatment (OST) as a LTMSP does not appear to protect against HCV seroconversion.

HIV, HCV and HBV: A Review of Parallels and Differences

Elimination of the three blood-borne viruses—human immunodeficiency virus (HIV), hepatitis B (HBV) and hepatitis C (HCV)—as public health issues may be plausible in the near future. Spectacular advances have been made with the introduction of highly effective antiviral agents into clinical practice, and prevention strategies are available for all three infections. Effective disease control, laid out by WHO global strategies, is currently feasible for all three viruses. However, for worldwide elimination of these viruses, effective vaccines are required that are currently only available for HBV. In this review differences and parallels among HIV, HCV and HBV will be discussed with a focus on virologic and therapeutic issues, and prospects for the future of HBV will be presented.

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

BACKGROUND

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

An educate, test, and treat programme towards elimination of hepatitis C infection in Egypt: a community-based demonstration project

BACKGROUND

Egypt has one of the highest prevalences and burdens of hepatitis C virus (HCV) worldwide, and a large government treatment programme. However, identifying and treating people who are infected in rural communities can be a substantial challenge. We designed and evaluated a comprehensive community-led outreach programme for prevention, testing, and treatment of HCV infection in one village in northern Egypt, with the goal to eliminate HCV infection from all adult villagers, and as a model for potential adoption in rural settings.

METHODS

A community-based education and test-and-treat project was established in Al-Othmanya village. The programme consisted of community mobilisation facilitated by a network of village promoters and establishment of partnerships; an educational campaign to raise awareness and promote behavioural changes; fundraising for public donations in the local community; and comprehensive testing, diagnosis, and treatment. For the educational campaign, we used public awareness events, house-to-house visits, and promotional materials (eg, booklets, cartoons, songs) to raise awareness of HCV and its transmission, and changes in knowledge, attitudes, and practices were measured through the use of a survey done before and after the educational campaign. Comprehensive testing, linkage to care, and treatment was offered to all eligible villagers (ie, those aged 12-80 years who had not previously been treated for HCV). Testing was done by use of HCV antibody and hepatitis B surface antigen (HBsAg) rapid diagnostic tests, with HCV-RNA PCR confirmation of positive cases, and staging of liver disease by use of transient elastography. HCV-RNA-positive participants were offered a 24-week course of sofosbuvir (400 mg orally, daily) and ribavirin (1000-1200 mg orally, daily) with an assessment of cure (sustained virological response) at 12 weeks after completion of treatment (SVR12).

FINDINGS

Between June 6, 2015, and June 9, 2016, 4215 (89%) of 4721 eligible villagers were screened for HCV antibodies and HBsAg. Of these participants, 530 (13%) were HCV antibody positive and eight (<1%) were HBsAg positive. All HCV-antibody-positive individuals had an HCV-RNA assay, and 312 (59%) were HCV-RNA positive. All 312 completed a full baseline assessment with staging of liver disease, and 300 (96%) were given 24 weeks of sofosbuvir and ribavirin treatment within a median of 2·3 weeks (IQR 0·0-3·7) from serological diagnosis. 293 (98%) of the treated participants achieved SVR12. 42 (13%) HCV-RNA-positive participants had cirrhosis as determined by transient elastography, of whom 12 (29%) were diagnosed with hepatocellular carcinoma on the basis of α-fetoprotein measurement and ultrasound. 3575 (85%) of 4215 eligible villagers completed the baseline and after educational campaign survey, and awareness, knowledge, and adoption of safer practices to prevent HCV transmission all significantly increased (p<0·0001).

INTERPRETATION

This community-led educate, test-and-treat demonstration project achieved high uptake of HCV testing, linkage to care and treatment, and attainment of cure in one village, as well as awareness and adoption of practices to prevent transmission in the community. This approach could be an important strategy for adoption in rural settings to complement the national government programme towards the elimination of HCV in Egypt.

FUNDING

Egyptian Liver Research Institute and Hospital.

The role of prevention strategies in achieving HCV elimination in Canada: what are the remaining challenges?

BACKGROUND

The worldwide economic, health, and social consequences of drug use disorders are devastating. Injection drug use is now a major factor contributing to hepatitis C virus (HCV) transmission globally, and it is an important public health concern.

METHODS

This article presents a narrative review of scientific evidence on public health strategies for HCV prevention among people who inject drugs (PWID) in Canada.

RESULTS

A combination of public health strategies including timely HCV detection and harm reduction (mostly needle and syringe programmes and opioid substitution therapy) have helped to reduce HCV transmission among PWID. The rising prevalence of pharmaceutical opioid and methamphetamine use and associated HCV risk in several Canadian settings has prompted further innovation in harm reduction, including supervised injection facilities and low-threshold opioid substitution therapies. Further significant decreases in HCV incidence and prevalence, and in corresponding disease burden, can only be accomplished by reducing transmission among high-risk persons and enhancing access to HCV treatment for those at the greatest risk of disease progression or viral transmission. Highly effective and tolerable direct-acting antiviral therapies have transformed the landscape for HCV-infected patients and are a valuable addition to the prevention toolkit. Curing HCV-infected persons, and thus eliminating new infections, is now a real possibility.

CONCLUSIONS

Prevention strategies have not yet ended HCV transmission, and sharing of injecting equipment among PWID continues to challenge the World Health Organization goal of eliminating HCV as a global public health threat by 2030. Future needs for research, intervention implementation, and uptake in Canada are discussed.

Direct medical costs associated with the extrahepatic manifestations of hepatitis C infection in Europe

Hepatitis C virus (HCV) infection is a systemic disease associated with both hepatic and extrahepatic manifestations. The burden associated with the hepatic manifestation of HCV infection has been well documented in Europe, although that of HCV extrahepatic manifestations remains unknown. In this study, we estimated the annual direct medical costs associated with HCV extrahepatic manifestations in five European countries. A previously validated economic model was used to estimate the annual direct medical cost associated with HCV extrahepatic manifestations. Global excess prevalence of extrahepatic manifestations in HCV patients relative to that in non-HCV patients was obtained from a recent meta-analysis. Per-patient per-year inpatient, outpatient and medication costs to treat each extrahepatic manifestation were from the literature, national databases or expert opinion if unavailable otherwise. All costs were adjusted to 2016 euros (€). The overall direct medical costs associated with HCV extrahepatic manifestations were calculated by multiplying the total per-patient per-year costs of each by the respective excess prevalence rates and then by the size of the HCV-infected population in each country. Treatment impact with direct-acting antivirals (DAAs) was explored using HCV extrahepatic manifestations excess prevalence rates among cured patients compared to untreated HCV patients, as sourced from a meta-analysis. The total annual direct medical cost associated with HCV extrahepatic manifestations was estimated to be 2.17 billion euro (€), with a per-HCV-patient cost ranging from €899 to €1647 annually. DAA treatment was projected to result in cost savings of €316 million per year. We find that the annual economic burden of extrahepatic manifestations is significant and may be partly mitigated by treatment with DAAs.

Population Health and Cost-Effectiveness Implications of a "Treat All" Recommendation for HCV: A Review of the Model-Based Evidence

The World Health Organization HCV Guideline Development Group is considering a "treat all" recommendation for persons infected with hepatitis C virus (HCV). We reviewed the model-based evidence of cost-effectiveness and population health impacts comparing expanded treatment policies to more limited treatment access policies, focusing primarily on evaluations of all-oral directly acting antivirals published after 2012. Searching PubMed, we identified 2,917 unique titles. Sequentially reviewing titles and abstracts identified 226 potentially relevant articles for full-text review. Sixty-nine articles met all inclusion criteria-42 cost-effectiveness analyses and 30 models of population-health impacts, with 3 articles presenting both types of analysis. Cost-effectiveness studies for many countries concluded that expanding treatment to people with mild liver fibrosis, who inject drugs (PWID), or who are incarcerated is generally cost-effective compared to more restrictive treatment access policies at country-specific prices. For certain patient subpopulations in some countries-for example, elderly individuals without fibrosis-treatment is only cost-effective at lower prices. A frequent limitation is the omission of benefits and consequences of HCV transmission (i.e., treatment as prevention; risks of reinfection), which may underestimate or overestimate the cost-effectiveness of a "treat all" policy. Epidemiologic modeling studies project that through a combination of prevention, aggressive screening and diagnosis, and prompt treatment for all fibrosis stages, it may be possible to virtually eliminate HCV in many countries. Studies show that if resources are not available to diagnose and treat all HCV-infected individuals, treatment prioritization may be needed, with alternative prioritization strategies resulting in tradeoffs between reducing mortality or reducing incidence. Notably, because most new HCV infections are among PWID in many settings, HCV elimination requires unrestricted treatment access combined with injection transmission disruption strategies. The model-based evidence suggests that a properly constructed strategy that substantially expands HCV treatment could achieve cost-effective improvements in population health in many countries.

The impact of HCV co-infection status on healthcare-related utilization among people living with HIV in British Columbia, Canada: a retrospective cohort study

Background

The burden of HCV among those living with HIV remains a major public health challenge. We aimed to characterize trends in healthcare-related visits (HRV) of people living with HIV (PLW-HIV) and those living with HIV and HCV (PLW-HIV/HCV), in British Columbia (BC), and to identify risk factors associated with the highest HRV rates over time.

Methods

Eligible individuals, recruited from the BC Seek and Treat for Optimal Prevention of HIV/AIDS population-based retrospective cohort (N = 3955), were ≥ 18 years old, first started combination antiretroviral therapy (ART) between 01/01/2000–31/12/2013, and were followed for ≥6 months until 31/12/2014. The main outcome was HRV rate. The main exposure was HIV/HCV co-infection status. We built a confounder non-linear mixed effects model, adjusting for several demographic and time-dependent factors.

Results

HRV rates have decreased since 2000 in both groups. The overall age-sex standardized HRV rate (per person-year) among PLW-HIV and PLW-HIV/HCV was 21.11 (95% CI 20.96–21.25) and 41.69 (95% CI 41.51–41.88), respectively. The excess in HRV in the co-infected group was associated with late presentation for ART, history of injection drug use, sub-optimal ART adherence and a higher number of comorbidities. The adjusted HRV rate ratio for PLW-HIV/HCV in comparison to PLW-HIV was 1.18 (95% CI 1.13–1.24).

Conclusions

Although HRV rates have decreased over time in both groups, PLW-HIV/HCV had 18% higher HRV than those only living with HIV. Our results highlight several modifiable risk factors that could be targeted as potential means to minimize the disease burden of this population and of the healthcare system.

Electronic supplementary material

The online version of this article (10.1186/s12913-018-3119-5) contains supplementary material, which is available to authorized users.

Is hepatitis C virus elimination possible among people living with HIV and what will it take to achieve it?

INTRODUCTION

The World Health Organization targets for hepatitis C virus (HCV) elimination include a 90% reduction in new infections by 2030. Our objective is to review the modelling evidence and cost data surrounding feasibility of HCV elimination among people living with HIV (PLWH), and identify likely components for elimination. We also discuss the real-world experience of HCV direct acting antiviral (DAA) scale-up and elimination efforts in the Netherlands.

METHODS

We review modelling evidence of what intervention scale-up is required to achieve WHO HCV elimination targets among HIV-infected (HIV+) people who inject drugs (PWID) and men who have sex with men (MSM), review cost-effectiveness of HCV therapy among PLWH and discuss economic implications of elimination. We additionally use the real-world experience of DAA scale-up in the Netherlands to illustrate the promise and potential challenges of HCV elimination strategies in MSM. Finally, we summarize key components of the HCV elimination response among PWLH.

RESULTS AND DISCUSSION

Modelling indicates HCV elimination among HIV+ MSM and PWID is potentially achievable but requires combination treatment and either harm reduction or behavioural risk reductions. Preliminary modelling indicates elimination among HIV+ PWID will require elimination efforts among PWID more broadly. Treatment for PLWH and high-risk populations (PWID and MSM) is cost-effective in high-income countries, but costs of DAAs remain a barrier to scale-up worldwide despite the potential low production price ($50 per 12 week course). In the Netherlands, universal DAA availability led to rapid uptake among HIV+ MSM in 2015/16, and a 50% reduction in acute HCV incidence among HIV+ MSM from 2014 to 2016 was observed. In addition to HCV treatment, elimination among PLWH globally also likely requires regular HCV testing, development of low-cost accurate HCV diagnostics, reduced costs of DAA therapy, broad treatment access without restrictions, close monitoring for HCV reinfection and retreatment, and harm reduction and/or behavioural interventions.

CONCLUSIONS

Achieving WHO HCV Elimination targets is potentially achievable among HIV-infected populations. Among HIV+ PWID, it likely requires HCV treatment scale-up combined with harm reduction for both HIV+ and HIV- populations. Among HIV+ MSM, elimination likely requires both HCV treatment and behaviour risk reduction among the HIV+ MSM population, the latter of which to date has not been observed. Lower HCV diagnostic and treatment costs will be key to ensuring scale-up of HCV testing and treatment without restriction, enabling elimination.

Outpatient directly observed therapy for hepatitis C among people who use drugs: a systematic review and meta-analysis

Objective: We conducted a meta-analysis of randomised studies that assessed the effectiveness of directly observed hepatitis C medication therapy delivered in outpatient clinics compared to treatment as usual. Methods: We completed a systematic literature review up to the end of August 2017, including online databases, study abstracts and references of pertinent articles. We assessed the results of randomised studies using the Cochrane Collaboration risk of bias assessment tool, and observational studies using the ROBINS-I tool. From each study, we extracted the number of patients who did or did not attain sustained virological response (SVR). We utilised a DerSimonian and Laird random effects model for our meta-analysis. This study is registered with PROSPERO (CRD42014012957). Results: We included six studies with 407 patients in our systematic review; four of those studies (215 patients) used randomisation and were included in our meta-analysis. Overall effect estimates showed that compared to treatment as usual, directly observed therapy demonstrated significantly higher odds of SVR attainment (odds ratio 2.01, 95% confidence interval 1.13-3.59). Conclusion: Among people who use drugs, directly observed therapy may lead to higher odds of attaining SVR. Further research on the best ways to use directly observed therapy to administer HCV therapy to people who use drugs is warranted.

Evaluation of dried blood spot samples for screening of hepatitis C and human immunodeficiency virus in a real-world setting

Both hepatitis C virus (HCV) infection and human immunodeficiency virus (HIV) infection are underdiagnosed, particularly in low-income countries and in difficult-to-access populations. Our aim was to develop and evaluate a methodology for the detection of HCV and HIV infection based on capillary dry blood spot (DBS) samples taken under real-world conditions. We carried out a cross-sectional study of 139 individuals (31 healthy controls, 68 HCV-monoinfected patients, and 40 HCV/HIV-coinfected patients). ELISA was used for anti-HCV and anti-HIV antibody detection; and SYBR Green RT-PCR was used for HCV-RNA detection. The HIV serological analysis revealed 100% sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). The HCV serological analysis revealed a sensitivity of 92.6%, specificity of 100%, PPV of 100%, and NPV of 79.5%. Finally, the HCV-RNA detection test revealed a detection limit of 5 copies/µl with an efficiency of 100% and sensitivity of 99.1%, specificity of 100%, PPV of 100%, and NPV of 96.9%. In conclusion, our methodology was able to detect both HCV infection and HIV infection from the same DBS sample with good diagnostic performance. Screening for HCV and HIV using DBS might be a key strategy in the implementation of national programs for the control of both infections.

Drug use and phylogenetic clustering of hepatitis C virus infection among people who use drugs in Vancouver, Canada: A latent class analysis approach

This study estimated latent classes (ie, unobserved subgroups in a population) of people who use drugs in Vancouver, Canada, and examined how these classes relate to phylogenetic clustering of hepatitis C virus (HCV) infection. HCV antibody-positive people who use drugs from two cohorts in Vancouver, Canada (1996-2012), with a Core-E2 sequence were included. Time-stamped phylogenetic trees were inferred, and phylogenetic clustering was determined by time to most common recent ancestor. Latent classes were estimated, and the association with the phylogenetic clustering outcome was assessed using an inclusive classify/analyse approach. Among 699 HCV RNA-positive participants (26% female, 24% HIV+), recent drug use included injecting cocaine (80%), injecting heroin (70%), injecting cocaine/heroin (ie, speedball, 38%) and crack cocaine smoking (28%). Latent class analysis identified four distinct subgroups of drug use typologies: (i) cocaine injecting, (ii) opioid and cocaine injecting, (iii) crack cocaine smoking and (iv) heroin injecting and currently receiving opioid substitution therapy. After adjusting for age and HIV infection, compared to the group defined by heroin injecting and currently receiving opioid substitution therapy, the odds of phylogenetic cluster membership was greater in the cocaine injecting group (adjusted OR [aOR]: 3.06; 95% CI: 1.73, 5.42) and lower in the crack cocaine smoking group (aOR: 0.06; 95% CI: 0.01, 0.48). Combining latent class and phylogenetic clustering analyses provides novel insights into the complex dynamics of HCV transmission. Incorporating differing risk profiles associated with drug use may provide opportunities to further optimize and target HCV treatment and prevention strategies.

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.

The Hotel Study-Clinical and Health Service Effectiveness in a Cohort of Homeless or Marginally Housed Persons

OBJECTIVE

The Hotel Study was initiated in Vancouver's Downtown East Side (DTES) neighborhood to investigate multimorbidity in homeless or marginally housed people. We evaluated the clinical effectiveness of existing, illness-specific treatment strategies and assessed the effectiveness of health care delivery for multimorbid illnesses.

METHOD

For context, we mapped the housing locations of patients presenting for 552,062 visits to the catchment hospital emergency department (2005-2013). Aggregate data on 22,519 apprehensions of mentally ill people were provided by the Vancouver Police Department (2009-2015). The primary strategy was a longitudinal cohort study of 375 people living in the DTES (2008-2015). We analysed mortality and evaluated the clinical and health service delivery effectiveness for infection with human immunodeficiency virus or hepatitis C virus, opioid dependence, and psychosis.

RESULTS

Mapping confirmed the association between poverty and greater number of emergency visits related to substance use and mental illness. The annual change in police apprehensions did not differ between the DTES and other policing districts. During 1581 person-years of cohort observation, the standardized mortality ratio was 8.43 (95% confidence interval, 6.19 to 11.50). Physician visits were common (84.3% of participants over 6 months). Clinical treatment effectiveness was highest for HIV/AIDS, intermediate for opioid dependence, and lowest for psychosis. Health service delivery mechanisms provided examples of poor access, poor treatment adherence, and little effect on multimorbid illnesses.

CONCLUSIONS

Clinical effectiveness was variable, and illness-specific service delivery appeared to have little effect on multimorbidity. New models of care may need to be implemented.

Discrepancies in prevalence trends for HIV, hepatitis B virus, and hepatitis C virus in Haiphong, Vietnam from 2007 to 2012

We previously reported a significant reduction in the prevalence of human immunodeficiency virus type 1 (HIV) from 2007 to 2012 in people who inject drugs (PWID; 35.9% to 18.5%, p < 0.001) and female sex workers (FSW; 23.1% to 9.8%, p < 0.05), but not in blood donors (BD) or pregnant women, in Haiphong, Vietnam. Our aim in the present study was to assess trends in the prevalence of infection with hepatitis B and C viruses (HBV and HCV, respectively). We also investigated the coinfection rates of HBV and HCV with HIV in the same groups. Between 2007 and 2012, HBV prevalence was significantly decreased in BD (18.1% vs. 9.0%, p = 0.007) and slightly decreased in FSW (11.0% vs. 3.9%, p = 0.21), but not in PWID (10.7% vs. 11.1%, p = 0.84). HCV prevalence was significantly decreased in PWID (62.1% in 2007 vs. 42.7% in 2008, p < 0.0001), but it had rebounded to 58.4% in 2012 (2008 vs. 2012, p < 0.0001). HCV prevalence also increased in FSW: 28.6% in 2007 and 2009 vs. 35.3% in 2012; however, this difference was not significant (2007 vs. 2012, p = 0.41). Rates of coinfection with HBV and HCV among HIV-infected PWID and FSW did not change significantly during the study period. Our findings suggest that the current harm reduction programs designed to prevent HIV transmission in PWID and FSW may be insufficient to prevent the transmission of hepatitis viruses, particularly HCV, in Haiphong, Vietnam. New approaches, such as the introduction of catch-up HBV vaccination to vulnerable adult populations and the introduction of HCV treatment as prevention, should be considered to reduce morbidity and mortality due to HIV and hepatitis virus coinfection in Vietnam.

Modeling Combination HCV Prevention among HIV-infected Men Who Have Sex With Men and People Who Inject Drugs

People who inject drugs (PWID) and HIV-infected men who have sex with men (MSM) are key risk groups for HCV transmission. Mathematical modeling studies can help elucidate what level and combination of prevention intervention scale-up is required to control or eliminate epidemics among these key populations. We discuss the evidence surrounding HCV prevention interventions and provide an overview of the mathematical modeling literature projecting the impact of scaled-up HCV prevention among PWID and HIV-infected MSM. Harm reduction interventions, such as opiate substitution therapy and needle and syringe programs, are effective in reducing HCV incidence among PWID. Modeling and limited empirical data indicate that HCV treatment could additionally be used for prevention. No studies have evaluated the effectiveness of behavior change interventions to reduce HCV incidence among MSM, but existing interventions to reduce HIV risk could be effective. Mathematical modeling and empirical data indicate that scale-up of harm reduction could reduce HCV transmission, but in isolation is unlikely to eliminate HCV among PWID. By contrast, elimination is possibly achievable through combination scale-up of harm reduction and HCV treatment. Similarly, among HIV-infected MSM, eliminating the emerging epidemics will likely require HCV treatment scale-up in combination with additional interventions to reduce HCV-related risk behaviors. In summary, elimination of HCV will likely require combination prevention efforts among both PWID and HIV-infected MSM populations. Further empirical research is required to validate HCV treatment as prevention among these populations, and to identify effective behavioral interventions to reduce HCV incidence among MSM.

Health-adjusted life expectancy in HIV-positive and HIV-negative men and women in British Columbia, Canada: a population-based observational cohort study

BACKGROUND

We sought to understand whether people living with HIV (PLHIV) ever on highly active antiretroviral therapy (ART) follow a pattern where morbidity is compressed into the last years of life or lessened as people age. We aimed to estimate health-adjusted life expectancy (HALE) among adults living with and without HIV, and examine dependency between causes of comorbidities.

METHODS

The Comparative Outcomes and Service Utilization Trends (COAST) study is a retrospective cohort of adults (≥20 years) including all known PLHIV and a 10% random sample of the general population of British Columbia, and with longitudinal data spanning from April 1, 1996, to Dec 31, 2012. We determined the prevalence of select comorbidities (cardiovascular, respiratory, liver, and renal diseases, and non-AIDS defining cancers because of their high prevalence among PLHIV) by age and sex by use of case-finding algorithms. Deaths were obtained from a vital event registry from British Columbia, Canada. Comorbid-specific HALE was estimated from 20 years of age by HIV status and sex. For each comorbidity, a healthy state was defined as the proportion of life expectancy comorbid-free, and was adjusted on the probability of occurrence of other different comorbidities. The sensitivity of HALE estimates was assessed to the sequencing of select comorbidities for the dependent comorbidity adjustments.

FINDINGS

Our sample consisted of electronic health records from 9310 HIV-infected and 510 313 uninfected adults over the period April 1, 1996, to Dec 31, 2012. These individuals contributed 49 605 deaths and 5 576 841 person-years over the study period. At exactly age 20 years, HALE was about 31 years (SD 0·16) among men living with HIV and 27 years (0·16) among women living with HIV. In the HIV-negative population, HALE was around 58 years (SD 0·02) for men and 63 years (0·02) for women. These results seem independent of ordering. However, PLHIV, particularly women living with HIV, had much shorter overall life expectancies than did their HIV-negative counterparts in the general population [29·1 years (SD 0·1) vs 65·4 years (0·1)], and thus spent less time in a healthy state.

INTERPRETATION

Although we noted little differences in the levels of morbidity compression by HIV status, PLHIV-especially women living with HIV-spent less time in a healthy state. Expanded service delivery interventions to address complex care needs of ageing PLHIV are crucial to address shorter life expectancies, and improve their healthy states.

FUNDING

Canadian Institutes of Health Research.

Value of Treating All Stages of Chronic Hepatitis C: A Comprehensive Review of Clinical and Economic Evidence

INTRODUCTION

The goal of chronic hepatitis C (CHC) treatment is to achieve a sustained virologic response (SVR). The new generation of direct-acting antivirals (DAAs) offers 90-100% SVR rates. However, access to these treatments is generally limited to patients with advanced liver disease. The aim of this review is to provide an overview of the clinical and economic benefits of achieving SVR and to better understand the full value of CHC treatment in all stages of liver disease.

METHODS

A comprehensive literature review was performed using the PubMed, Embase, and Cochrane library databases to identify articles examining the clinical, economic, and quality of life benefits associated with SVR. Articles were limited to those published in English language from January 2006 through January 2016. Inclusion criteria were (1) patients with CHC, (2) retrospective and prospective studies, (3) reporting of mortality, liver morbidity, extrahepatic manifestations (EHMs), and economic outcomes and, (4) availability of an abstract or full-text publication.

RESULTS

Overall this review identified 354 studies involving more than 500,000 CHC patients worldwide. Evidence from 38 studies (n = 73,861) shows a significant mortality benefit of achieving SVR in patients with all stages of fibrosis. Long-term studies with follow-up of 5-12 years suggest that, particularly among non-cirrhotic patients, there is a significant decrease in mortality in SVR versus non-SVR groups. Ninety-nine studies conducted in 235,891 CHC patients in all stages of fibrosis show that SVR reduces liver-related mortality, incidence of hepatocellular carcinoma (HCC), and decompensation. A total of 233 studies show that chronic HCV infection is associated with several serious EHMs, some of which can have high mortality. Evidence from four modeling studies shows that delaying treatment to CHC patient populations could significantly increase mortality, morbidity, and medical costs.

CONCLUSIONS

There is a robust body of evidence demonstrating diverse sources of value from achieving SVR in all stages of liver disease. While access to treatment is generally limited to late-stage patients, less restrictive treatment strategies that target HCV eradication have the potential to abate the burdens of mortality, liver morbidity and extrahepatic manifestations, and the associated healthcare costs.

Inability to access health and social services associated with mental health among people who inject drugs in a Canadian setting

BACKGROUND

People who inject drugs (PWID) face barriers to healthcare due to reasons including comorbidity. We evaluated access to health and social services by three of the most prevalent comorbid conditions among PWID: HIV, hepatitis C (HCV), and mental health, in an urban setting in Canada.

METHODS

Data were derived from prospective cohorts of community-recruited PWID between 2005 and 2015. HIV and HCV serostatuses were based on antibody tests, while mental health conditions and inability to access health and social services (barriers to access) were determined by participants' self-report. We employed generalized linear mixed models controlling for confounders to examine associations between health conditions and barriers to access.

RESULTS

Among 2494 participants, 1632 (65.4%) reported barriers to access at least once over a median of seven (IQR: 3, 12) semi-annual assessments. Mental health conditions were independently associated with increased odds of reporting barriers (adjusted Odds Ratio (aOR): 1.45, 95% Confidence Interval (CI): 1.32, 1.58), while HIV was not (aOR: 0.96, 95% CI: 0.85, 1.08), and HCV was associated with decreased odds (aOR: 0.80, 95% CI: 0.69, 0.93). The associations between mental health conditions and barriers to access were consistent among PWID without HIV/HCV (aOR: 1.35, 95% CI: 1.10, 1.65), with HCV mono-infection (aOR: 1.55, 95% CI: 1.37, 1.75), and HCV/HIV co-infection (aOR: 1.36, 95% CI: 1.15, 1.60).

CONCLUSIONS

Targeted strategies to seek and treat mental health conditions in settings that serve PWID, and assist PWID with mental health conditions in navigating healthcare system may improve the publicly-funded health and social services.

Conditions for eradicating hepatitis C in people who inject drugs: A fibrosis aware model of hepatitis C virus transmission

It is estimated that 80% of new hepatitis C virus (HCV) infections occur among people who inject drugs (PWID). Eradicating HCV from this population is key for the complete eradication of the disease, and the advent of simple to use, high efficacy treatments could conceivably make this scenario possible. This paper presents a mathematical model where transmission of HCV is studied in a simulated population of PWID where fibrosis progression is explicitly tracked. The stability thresholds that determine whether HCV will remain endemic or become eradicated were established numerically, and analytically on a reduced version of the model. Conditions on testing and treatment rates for eradication to occur were determined, within the context of the new high efficacy therapies. The results show that HCV eradication in the PWID population of the Vancouver, BC test scenario is achievable, but testing and especially treatment rates will need to increase significantly from current rates. Parameter estimates were drawn from published data.