A review of the evidence for the effectiveness of primary prevention interventions for hepatitis C among injecting drug users

Overdose prevention centres as spaces of safety, trust and inclusion: A causal pathway based on a realist review

ISSUES

Overdose prevention centres (OPC) are non-residential spaces where people can use illicit drugs (that they have obtained elsewhere) in the presence of staff who can intervene to prevent and manage any overdoses that occur. Many reviews of OPCs exist but they do not explain how OPCs work.

APPROACH

We carried out a realist review, using the RAMESES reporting standards. We systematically searched for and then thematically analysed 391 documents that provide information on the contexts, mechanisms and outcomes of OPCs.

KEY FINDINGS

Our retroductive analysis identified a causal pathway that highlights the feeling of safety - and the immediate outcome of not dying - as conditions of possibility for the people who use OPCs to build trust and experience social inclusion. The combination of safety, trust and social inclusion that is triggered by OPCs can - depending on the contexts in which they operate - generate other positive outcomes, which may include less risky drug use practices, reductions in blood borne viruses and injection-related infections and wounds, and access to housing. These outcomes are contingent on relevant contexts, including political and legal environments, which differ for women and people from racialised minorities.

CONCLUSIONS

OPCs can enable people who live with structural violence and vulnerability to develop feelings of safety and trust that help them stay alive and to build longer term trajectories of social inclusion, with potential to improve other aspects of their health and living conditions.

Estimating the Allocation of the Economic Value Generated by Utilization of All-Oral Direct-Acting Antivirals for Hepatitis C in the United States, 2015 to 2019

OBJECTIVES

Between 2013 to 2019, several all-oral direct-acting antivirals (DAAs) were launched with the potential to cure patients with hepatitis C virus (HCV). They generated economic value in terms of the health gains for patients and cost-savings for the US healthcare system. We estimated the share of this value allocated to 4 manufacturers vs society.

METHODS

For 2015 to 2019, we estimated the incremental impact of DAAs on HCV health outcomes and costs. We used the Center for Disease Analysis Foundation Polaris Observatory database to estimate utilization. Per-patient projections of lifetime quality-adjusted life-years (QALYs) gained and medical costs avoided were based on a standard 9-state HCV disease-progression model for DAA treatment vs alternatives. Annual QALY gains were valued at $114 000 per QALY. Outcomes and costs were discounted at 3%. Estimated revenues were based on reported sales.

RESULTS

An estimated 1 080 000 patients received DAAs: 81.5% would not have received the pre-DAA standard of care. On average, these patients were projected to gain 4.4 QALYs and save $104 400 in lifetime healthcare costs, generating $531.8 billion in value. Those who would have received treatment gained 1.7 QALYs and saved $41 500 in lifetime costs, generating $47.4 billion in economic value. As treatment costs fell nearly 75%, the 4 manufacturers reported $37.4 billion from DAA sales-an allocation of 6.5% of the total value.

CONCLUSIONS

The significant majority (∼90%) of the economic value of curing HCV with DAAs were health benefits to patients and net cost-savings to society. DAA manufacturers received a minority share (6.5%) of the aggregate economic value generated.

Impact of harm minimization interventions on reducing blood-borne infection transmission and some injecting behaviors among people who inject drugs: an overview and evidence gap mapping

BACKGROUND

This study aimed to synthetize the evidence on the effectiveness of harm minimization interventions on reducing blood-borne infection transmission and injecting behaviors among people who inject drugs (PWID) through a comprehensive overview of systematic reviews and evidence gap mapping.

METHODS

A systematic review was conducted with searches in PubMed and Scopus to identify systematic reviews assessing the impact of interventions aimed at reducing the harms associated with injectable drug use. The overall characteristics of the studies were extracted and their methodological quality was assessed using AMSTAR-2. An evidence gap map was constructed, highlighting the most frequently reported outcomes by intervention (CRD42023387713).

RESULTS

Thirty-three systematic reviews were included. Of these, 14 (42.2%) assessed the impact of needle/syringe exchange programs (NSEP) and 11 (33.3%) examined opioid agonist therapy (OAT). These interventions are likely to be associated with reductions of HIV/HCV incidence (10-40% risk reduction for NSEP; 50-60% for OAT) and sharing injecting paraphernalia (50% for NSEP, 25-85% for OAT), particularly when combined (moderate evidence). Behavioral/educational interventions were assessed in 12 reviews (36.4%) with most authors in favor/partially in favor of the use of these approaches (moderate evidence). Take-home naloxone programs and supervised-injection facilities were each assessed in two studies (6.1%), which reported inconclusive results (limited/inconsistent evidence). Most authors reported high levels of heterogeneity and risk of bias. Other interventions and outcomes were inadequately reported. Most systematic reviews presented low or critically low quality.

CONCLUSION

The evidence is sufficient to support the effectiveness of OAT, NSEP and their combination in reducing blood-borne infection transmission and certain injecting behaviors among PWID. However, evidence of other harm minimizations interventions in different settings and for some outcomes remain insufficient.

Effectiveness of interventions for prevention of common infections in people who use opioids: a protocol for a systematic review of systematic reviews

BACKGROUND

The North American opioid crisis is driven by opioid-related mortality and morbidity, including opioid use-associated infections (OUAIs), resulting in a substantial burden for society. Users of legal and illegal opioids are at an increased risk of OUAIs compared to individuals not using opioids. As reported for hepatitis C virus (HCV), human immunodeficiency virus (HIV), bacterial, fungal, and other infections, OUAIs transmission and acquisition risks may be modifiable. Several systematic reviews (SRs) synthetized data regarding interventions to prevent infections in persons using drugs (e.g., opioid substitution therapy, needle and syringes exchange programs, psycho-social interventions); however, their conclusions varied. Therefore, SR of published SRs is needed to synthesize the highest level of evidence on the scope and effectiveness of interventions to prevent OUAIs in people using opioids legally or illegally.

METHODS

We will comprehensively search for SRs in the PubMed, Embase, PsycINFO, Cochrane Database of Systematic Reviews, Epistemonikos, and Google Scholar databases from inception to November 2020. Data selection and extraction for each SR will be performed independently by two researchers, with disagreements resolved by consensus. All SRs regarding interventions with evaluated effectiveness to prevent OUAI in legal and/or illegal opioid users will be eligible. Risk of bias assessment will be performed using the AMSTAR2 tool. The results will be qualitatively synthesized, and a typology of interventions' effectiveness with a statement on the strength of evidence for each category will be created.

DISCUSSION

Our pilot search of PubMed resulted in 379 SRs analyzing the effectiveness of interventions to prevent HCV and HIV in persons who inject different types of drugs, including opioids. Of these 379 SRs, 8 evaluated primary studies where participants used opioids and would therefore be eligible for inclusion. The search results thus justify the application of SR of SRs approach. Comprehensive data on the scope and effectiveness of existing interventions to prevent OUAIs will help policy-makers to plan and implement preventive interventions and will assist clinicians in the guidance for their patients using opioids.

SYSTEMATIC REVIEW REGISTRATION

Registered in PROSPERO on 30 July 2020 ( #195929 ).

The state of harm reduction in prisons in 30 European countries with a focus on people who inject drugs and infectious diseases

BACKGROUND

People who inject drugs are often imprisoned, which is associated with increased levels of health risks including overdose and infectious diseases transmission, affecting not only people in prison but also the communities to which they return. This paper aims to give an up-to-date overview on availability, coverage and policy framework of prison-based harm reduction interventions in Europe.

METHODS

Available data on selected harm reduction responses in prisons were compiled from international standardised data sources and combined with a questionnaire survey among 30 National Focal Points of the European Monitoring Centre for Drugs and Drug Addiction to determine the level of availability, estimated coverage and policy framework of the interventions.

RESULTS

Information about responses to health harms in prisons is limited and heterogeneous. Cross-country comparability is hampered by diverging national data collection methods. Opioid substitution treatment (OST) is available in 29 countries, but coverage remains low (below 30% of people in need) in half of the responding countries. Needle and syringe programmes, lubricant distribution, counselling on safer injecting and tattooing/piercing are scarcely available. Testing for infectious diseases is offered but mostly upon prison entry, and uptake remains low in about half of the countries. While treatment of infections is mostly available and coverage is high for human immunodeficiency virus (HIV) and tuberculosis, hepatitis B and C treatment are less often provided. Health education as well as condom distribution is usually available, but provision remains low in nearly half of the countries. Post-release linkage to addiction care as well as to treatment of infections is available in a majority of countries, but implementation is often partial. Interventions recommended to be provided upon release, such as OST initiation, take-home naloxone and testing of infections, are rarely provided. While 21 countries address harm reduction in prison in national strategic documents, upon-release interventions appear only in 12.

CONCLUSIONS

Availability and coverage of harm reduction interventions in European prisons are limited, compared to the community. There is a gap between international recommendations and 'on-paper' availability of interventions and their actual implementation. Scaling up harm reduction in prison and throughcare can achieve important individual and public-health benefits.

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.

The value of cure associated with treating treatment-naïve chronic hepatitis C genotype 1: Are the new all-oral regimens good value to society?

BACKGROUND & AIMS

All-oral regimens are associated with high cure rates in hepatitis C virus-genotype 1 (HCV-GT1) patients. Our aim was to assess the value of cure to the society for treating HCV infection.

METHODS

Markov model for HCV-GT1 projected long-term health outcomes, life years, and quality-adjusted life years (QALYs) gained. The model compared second-generation triple (sofosbuvir+pegylated interferon+ribavirin [PR] and simeprevir+PR) and all-oral (ledipasvir/sofosbuvir and ombitasvir+paritaprevir/ritonavir+dasabuvir±ribavirin) therapies with no treatment. Sustained virological response rates were based on Phase III RCTs. We assumed that 80% and 95% of HCV-GT1 patients were eligible for second-generation triple and all-oral regimens. Transition probabilities, utility and mortality were based on literature review. The value of cure was calculated by the difference in the savings from the economic gains associated with additional QALYs.

RESULTS

Model estimated 1.52 million treatment-naïve HCV-GT1 patients in the US. Treating all eligible HCV-GT1 patients with second-generation triple and all-oral therapies resulted in 3.2 million and 4.8 million additional QALYs gained compared to no treatment respectively. Using $50,000 as value of QALY, these regimens lead to savings of $185 billion and $299 billion; costs of these regimens were $109 billion and $128 billion. The value of cure with second-generation triple and all-oral regimens was $55 billion and $111 billion, when we conservatively assumed only drug costs. Cost savings were greater for HCV-GT1 patient cured with cirrhosis compared to patients without cirrhosis.

CONCLUSIONS

The recent evolution of regimens for HCV GT1 has increased efficacy and value of cure.

Effectiveness of needle and syringe Programmes in people who inject drugs - An overview of systematic reviews

BACKGROUND

Needle and syringe programmes (NSP) are a critical component of harm reduction interventions among people who inject drugs (PWID). Our primary objective was to summarize the evidence on the effectiveness of NSP for PWID in reducing blood-borne infection transmission and injecting risk behaviours (IRB).

METHODS

We conducted an overview of systematic reviews that included PWID (excluding prisons and consumption rooms), addressed community-based NSP, and provided estimates of the effect regarding incidence/prevalence of Human Immunodeficiency Virus (HIV), Hepatitis C virus (HCV), Hepatitis B virus (HBV) and bacteremia/sepsis, and/or measures of IRB. Systematic literature searches were undertaken on relevant databases, including EMBASE, MEDLINE, and PsychINFO (up to May 2015). For each review we identified relevant studies and extracted data on methods, and findings, including risk of bias and quality of evidence assessed by review authors. We evaluated the risk of bias of each systematic review using the ROBIS tool. We categorized reviews by reported outcomes and use of meta-analysis; no additional statistical analysis was performed.

RESULTS

We included thirteen systematic reviews with 133 relevant unique studies published between 1989 and 2012. Reported outcomes related to HIV (n = 9), HCV (n = 8) and IRB (n = 6). Methods used varied at all levels of design and conduct, with four reviews performing meta-analysis. Only two reviews were considered to have low risk of bias using the ROBIS tool, and most included studies were evaluated as having low methodological quality by review authors. We found that NSP was effective in reducing HIV transmission and IRB among PWID, while there were mixed results regarding a reduction of HCV infection. Full harm reduction interventions provided at structural level and in multi-component programmes, as well as high level of coverage, were more beneficial.

CONCLUSIONS

The heterogeneity and the overall low quality of evidence highlights the need for future community-level studies of adequate design to support these results.

TRIAL REGISTRATION

The protocol of this systematic review was registered in Prospective Register of Systematic Reviews (PROSPERO 2015: CRD42015026145 ).

"Hep C, where art thou": What are the remaining (fundable) questions in hepatitis C virus research?

Hepatitis C virus (HCV) has dominated the field of hepatology for the past 25 years, and its cure in the majority of treated patients is one of the greatest achievements in all of medicine. However, the latter has led to the belief by some that HCV research should be shelved for other, more pressing areas. The mission for HCV eradication is far from accomplished. As a historical reference, we should consider that disease elimination has required vaccination with all previously controlled infections including smallpox and polio and that simple, effective treatment is not sufficient in most infections to lead to substantial control. Syphilis is the best example, for which a single dose of penicillin (which literally costs pennies and that we have had since 1945) is curative in early stages. Not only have we not eradicated syphilis, rates of infection have increased in many places within the United States in recent years. Most HCV-infected subjects are unaware of their infection, remaining at risk for transmission to others and disease progression, including cirrhosis and hepatocellular carcinoma. In the era of highly effective direct-acting antivirals (DAAs), many questions pertaining to HCV remain, but they are more complex and difficult to answer. Here, I provide my perspective on some of these salient issues: the residual risk for disease progression after sustained virologic response, the optimal approach to current DAA failures, the impact of targeting people who inject drugs with DAAs, vaccine prospects, and application of neutralizing HCV glycoprotein antibodies. (Hepatology 2017;65:341-349).

Assessment of cost of innovation versus the value of health gains associated with treatment of chronic hepatitis C in the United States: The quality-adjusted cost of care

BACKGROUND

New direct-acting antiviral (DAA) therapy has dramatically increased cure rates for patients infected with hepatitis C virus (HCV), but has also substantially raised treatment costs.

AIM

The aim of this analysis was to evaluate the therapeutic benefit and net costs (i.e. efficiency frontier) and the quality-adjusted cost of care associated with the evolution of treatment regimens for patients with HCV genotype 1 in the United States.

DESIGN

A decision-analytic Markov model.

DATA SOURCE

Published literature and clinical trial data.

TIME HORIZON

Life Time.

PERSPECTIVE

Third-party payer.

INTERVENTION

This study compared four approved regimens in treatment-naïve genotype 1 chronic hepatitis C patients, including pegylated interferon and ribavirin (PR), first generation triple therapy (boceprevir + PR and telaprevir + PR), second generation triple therapy (sofosbuvir + PR and simeprevir + PR) and all-oral DAA regimens (ledipasvir/sofosbuvir and ombitasvir + paritaprevir/ritonavir + dasabuvir ± ribavirin).

OUTCOME MEASURE

Quality-adjusted cost of care (QACC). QACC was defined as the increase in treatment cost minus the increase in the patient's quality-adjusted life years (QALYs) when valued at $50,000 per QALY.

RESULTS

All-oral therapy improved the average sustained virologic response (SVR) rate to 96%, thereby offsetting the high drug acquisition cost of $85,714, which resulted in the highest benefit based on the efficiency frontier. Furthermore, while oral therapies increased HCV drug costs by $48,350, associated QALY gains decreased quality-adjusted cost of care by $14,120 compared to dual therapy. When the value of a QALY was varied from $100,000 to $300,000, the quality adjusted cost of care compared to dual therapy ranged from - $21,234 to - $107,861, - $89,007 to - $293,130, - $176,280 to - $500,599 for first generation triple, second generation triple, and all-oral therapies, respectively. Primary efficacy and safety measurements for drug regimens were sourced from clinical trials data rather than a real-world setting. Factors such as individual demographic characteristics, comorbidities and alcohol consumption of the individual patients treated may alter disease progression but were not captured in this analysis.

CONCLUSION

New DAA treatments provide short-term and long-term clinical and economic value to society.

PRIMARY FUNDING SOURCE

Gilead Sciences, Inc.

A longitudinal study of hepatitis C virus testing and infection status notification on behaviour change in people who inject drugs

BACKGROUND

Hepatitis C virus (HCV) testing and counselling have the potential to impact individual behaviour and transmission dynamics at the population level. Evidence of the impact of an HCV-positive status notification on injection risk reduction is limited. The objective of our study was to (1) assess drug and alcohol use and injection risk behaviours following notification; (2) to compare behaviour change in people who inject drugs (PWID) who received a positive test result and those who remained negative; and (3) to assess the effect of age on risk behaviour.

METHODS

Data from the International Collaboration of Incident HIV and HCV Infection in Injecting Cohorts (InC3 Study) were analysed. Participants who were initially HCV seronegative were followed prospectively with periodic HCV blood testing and post-test disclosure and interview-administered questionnaires assessing drug use and injection behaviours. Multivariable generalised estimating equations were used to assess behavioural changes over time.

RESULTS

Notification of an HCV-positive test was independently associated with a small increase in alcohol use relative to notification of a negative test. No significant differences in postnotification injection drug use, receptive sharing of ancillary injecting equipment and syringe borrowing postnotification were observed between diagnosis groups. Younger PWID receiving a positive HCV test notification demonstrated a significant increase in subsequent alcohol use compared with younger HCV negative.

CONCLUSIONS

The proportion of PWID reporting alcohol use increased among those receiving an HCV-positive notification, increased the frequency of alcohol use postnotification, while no reduction in injection drug use behaviours was observed between notification groups. These findings underscore the need to develop novel communication strategies during post-test notification to improve their impact on subsequent alcohol use and risk behaviours.

Cost-effectiveness of all-oral ledipasvir/sofosbuvir regimens in patients with chronic hepatitis C virus genotype 1 infection

BACKGROUND

An all-oral, pegylated interferon (pegIFN)-free and ribavirin (RBV)-free single-tablet of ledipasvir (LDV) and sofosbuvir (SOF) is now approved for the treatment of patients infected with hepatitis C virus (HCV) genotype 1.

AIM

To estimate the health economic outcomes for LDV/SOF compared with current treatments in US patients infected with HCV genotype 1.

METHODS

A hybrid decision-tree and Markov state-transition model was developed. For a cohort of 10,000 patients, the model captured outcomes for several pairings of LDV/SOF with comparators, including long-term health outcomes, number need to treat, life-years gained, quality-adjusted life-years (QALYS) gained, incremental cost-effectiveness ratios and costs per sustained virologic response (SVR). Patients with different levels of treatment experience and different cirrhosis stages were included.

RESULTS

LDV/SOF decreased the number of advanced liver disease cases by 0-93% compared with current regimens or no treatment in treatment-naïve patients. In treatment-experienced [pegIFN plus ribavirin (PR) or protease inhibitor (PI) + PR] patients, treatment with LDV/SOF decreased the incidence of advanced liver disease complications in most of the cases analysed, except SOF + SMV. For all patient sub-cohorts, LDV/SOF was associated with the lowest 1-year costs per SVR and, with regard to lifetime incremental costs per QALY gained, was either dominant or the most cost-effective treatment. Overall, treatment initiation at earlier stages of liver fibrosis resulted in improved health economic outcomes.

CONCLUSION

LDV/SOF is associated with more favourable short- and long-term health economic outcomes compared with current therapies for patients across all levels of treatment experience and cirrhosis stages.

Gender influences on hepatitis C incidence among street youth in a Canadian setting

PURPOSE

Few studies have examined gender-based differences in the risk of hepatitis C virus (HCV) infection among street-involved youth. We compared rates of HCV infection among male and female street-involved youth in a Canadian setting.

METHODS

The At-Risk Youth Study is a prospective cohort of drug-using street-involved youth. Study recruitment and follow-up occurred in Vancouver, Canada, between September 2005 and November 2011. Eligible participants were illicit drug-using youth aged 14-26 years at enrollment, recruited by street-based outreach. We evaluated rates of HCV antibody seroconversion, measured every 6 months during study follow-up, and used Cox proportional hazards regression to compare risk factors for HCV incidence between male and female street youth.

RESULTS

Among 512 HCV-seronegative youth contributing 836 person-years of follow-up, 56 (10.9%) seroconverted to HCV. Among female participants, the incidence density of HCV infection was 10.9 per 100 person-years, and in males, it was 5.1 per 100 person-years (p = .009). In multivariate analyses, female gender was independently associated with a higher rate of HCV seroconversion (adjusted hazard ratio, 2.01; 95% confidence interval, 1.18-3.44). Risk factors were similar in gender-stratified analyses and included heroin injection and crystal methamphetamine injection, although syringe sharing was only associated with HCV incidence among males.

CONCLUSIONS

Among street-involved youth in this setting, females had double the incidence of HCV seroconversion demonstrating the need for gender-focused HCV prevention interventions for this population.

Hepatitis C avoidance in injection drug users: a typology of possible protective practices

Introduction

Hepatitis C virus (HCV) represents a serious public health concern. People who inject drugs (PWID) are at particular risk and nearly half (45%) of PWID in England may be infected. HCV prevention interventions have only had moderate impact on the prevalence of HCV in this population. Using qualitative methods, we sought to detail the protective practices potentially linked to HCV avoidance among PWID, and explore the motivations for these.

Methods

The study used a life history approach allowing participants to detail their lived experience both before and during the course of their injecting careers. Thirty-seven participants were recruited from drug services in London, and from referrals within local injecting networks. A baseline and follow-up in-depth qualitative interview was carried out with each participant, and for half, a third interview was also undertaken. All underwent testing for HCV antibody. Analyses focused on developing a descriptive typology of protective practices potentially linked to HCV avoidance.

Results

Practices were deemed to be protective against HCV if they could be expected a priori to reduce the number of overall injections and/or the number of injections using shared injecting equipment. Participants reported engaging in various protective practices which fell into three categories identified through thematic analysis: principles about injecting, preparedness, and flexibility.

Conclusions

All participants engaged in protective practices irrespective of serostatus. It is important to consider the relative importance of different motivations framing protective practices in order to formulate harm reduction interventions which appeal to the situated concerns of PWID, especially given that these protective practices may also help protect against HIV and other blood borne infections.

Interventions to prevent HIV and Hepatitis C in people who inject drugs: a review of reviews to assess evidence of effectiveness

BACKGROUND

Injecting drug use is a major risk factor for the acquisition and transmission of HIV and Hepatitis C virus (HCV). Prevention of these infections among people who inject drugs (PWID) is critical to reduce ongoing transmission, morbidity and mortality.

METHODS

A review of reviews was undertaken involving systematic literature searches of Medline, Embase, CINAHL, PsychINFO, IBSS and the Cochrane Library (2000-2011) to identify English language reviews regarding the effectiveness of harm reduction interventions in relation to HIV transmission, HCV transmission and injecting risk behaviour (IRB). Interventions included needle and syringe programmes (NSP); the provision of injection paraphernalia; opiate substitution treatment (OST); information, education and counselling (IEC); and supervised injecting facilities (SIFs). Reviews were classified into 'core' or 'supplementary' using critical appraisal criteria, and the strength of review-level evidence was assessed.

RESULTS

Twelve core and thirteen supplementary reviews were included. From these reviews we identified: (i) for NSP: tentative review-level evidence to support effectiveness in reducing HIV transmission, insufficient review-level evidence relating to HCV transmission, but sufficient review-level evidence in relation to IRB; (ii) for OST: sufficient review-level evidence of effectiveness in relation to HIV transmission and IRB, but tentative review-level evidence in relation to HCV transmission; (iii) for IEC, the provision of injection paraphernalia and SIFs: tentative review-level evidence of effectiveness in reducing IRB; and either insufficient or no review-level evidence for these interventions in relation to HIV or HCV transmission.

CONCLUSION

Review-level evidence indicates that harm reduction interventions can reduce IRB, with evidence strongest for OST and NSP. However, there is comparatively little review-level evidence regarding the effectiveness of these interventions in preventing HCV transmission among PWID. Further studies are needed to assess the effectiveness and impact of scaling up comprehensive packages of harm reduction interventions to minimise HIV and HCV transmission among PWID.

Minimal transmission of HIV despite persistently high transmission of hepatitis C virus in a Swedish needle exchange program

The aim of this study was to examine the prevalence and incidence of HIV and hepatitis B and C (HBV and HCV) among injecting drug users in a Swedish needle exchange programme (NEP) and to identify risk factors for blood-borne transmission. A series of serum samples from NEP participants enrolled from 1997 to 2005 were tested for markers of HIV, HBV and HCV (including retrospective testing for HCV RNA in the last anti-HCV-negative sample from each anti-HCV seroconverter). Prevalence and incidence were correlated with self-reported baseline characteristics. Among 831 participants available for follow-up, one was HIV positive at baseline and two seroconverted to anti-HIV during the follow-up of 2433 HIV-negative person-years [incidence 0.08 per 100 person-years at risk (pyr); compared to 0.0 in a previous assessment of the same NEP covering 1990-1993]. The corresponding values for HBV were 3.4/100 pyr (1990-1993: 11.7) and for HCV 38.3/100 pyr (1990-1993: 27.3). HCV seroconversions occurred mostly during the first year after NEP enrolment. Of the 332 cases testing anti-HCV negative at enrolment, 37 were positive for HCV RNA in the same baseline sample (adjusted HCV incidence 31.5/100 pyr). HCV seroconversion during follow-up was significantly associated with mixed injection use of amphetamine and heroin, and a history of incarceration at baseline. In this NEP setting, HIV prevalence and incidence remained low and HBV incidence declined because of vaccination, but transmission of HCV was persistently high. HCV RNA testing in anti-HCV-negative NEP participants led to more accurate identification of timepoints for transmission.

A systematic review and meta-analysis of interventions to prevent hepatitis C virus infection in people who inject drugs

INTRODUCTION

High rates of hepatitis C virus (HCV) transmission are found in samples of people who inject drugs (PWID) throughout the world. The objective of this paper was to meta-analyze the effects of risk-reduction interventions on HCV seroconversion and identify the most effective intervention types.

METHODS

We performed a systematic review and meta-analysis of published and unpublished studies. Eligible studies reported on the association between participation in interventions intended to reduce unsafe drug injection and HCV seroconversion in samples of PWID.

RESULTS

The meta-analysis included 26 eligible studies of behavioral interventions, substance-use treatment, syringe access, syringe disinfection, and multicomponent interventions. Interventions using multiple combined strategies reduced risk of seroconversion by 75% (pooled relative risk, .25; 95% confidence interval, .07-.83). Effects of single-method interventions ranged from .6 to 1.6.

CONCLUSIONS

Interventions using strategies that combined substance-use treatment and support for safe injection were most effective at reducing HCV seroconversion. Determining the effective dose and combination of interventions for specific subgroups of PWID is a research priority. However, our meta-analysis shows that HCV infection can be prevented in PWID.

Changes in blood-borne infection risk among injection drug users

BACKGROUND

Population-level hepatitis C virus (HCV) infection incidence is a surrogate for community drug-related risk.

METHODS

We characterized trends in human immunodeficiency virus (HIV) and HCV infection incidence and HCV infection prevalence among injection drug users (IDUs) recruited over 4 periods: 1988-1989, 1994-1995, 1998, and 2005-2008. We calculated HIV and HCV infection incidence within the first year of follow-up among IDUs whose test results were negative for these viruses at baseline (n = 2061 and n = 373, respectively). We used Poisson regression to compare trends across groups.

RESULTS

HIV infection incidence declined significantly from 5.5 cases/100 person-years (py) in the 1988-1989 group to 2.0 cases/100 py in the 1994-1995 group to 0 cases/100 py in the 1998 and 2005-2008 groups. Concurrently, HCV infection incidence declined but remained robust (22.0 cases/100 py in the 1988-1989 cohort to 17.2 cases/100 py in the 1994-1995 cohort, 17.9 cases/100 py in the 1998 cohort, and 7.8 cases/100 py in the 2005-2008 cohort; P = .07). Likewise, HCV infection prevalence declined, but chiefly in younger IDUs. For persons aged <39 years, relative to the 1988-1989 cohort, all groups exhibited significant declines (adjusted prevalence ratio [PR] for the 2005-08 cohort, .73; 95% confidence interval [CI], .65-.81). However, for persons aged ≥ 39 years, only the 2005-2008 cohort exhibited declining prevalence compared with the 1988-1989 cohort (adjusted PR, .87; 95% CI, .77-.99).

CONCLUSIONS

Although efforts to reduce blood-borne infection incidence have had impact, this work will need to be intensified for the most transmissible viruses, such as HCV.

Incidence of primary hepatitis C infection and risk factors for transmission in an Australian prisoner cohort

BACKGROUND

Hepatitis C virus (HCV) infection is common in prisoner populations, particularly those with a history of injecting drug use (IDU). Previous studies of HCV incidence have been based on small case numbers and have not distinguished risk events in prison from those in the community.

METHODS

HCV incidence was examined in a longitudinal cohort of 488 Australian prisoners with a history of IDU and documented to be seronegative within 12 months prior to enrollment. Inmates were tested for anti-HCV antibodies and viremia, and interviewed about demographic and behavioral risk factors for transmission.

RESULTS

The cohort was predominantly male (65%) with high rates of prior imprisonment (72%) and tattooing (73%), as well as longstanding IDU (mean 8.5 years). Ninety-four incident HCV cases were identified (incidence 31.6 per 100 person years). Independent associations were observed between incident infection and prior imprisonment (p = 0.02) and tattooing (p = 0.03), and surprisingly also with methadone maintenance treatment (MMT) (p < 0.001).

CONCLUSIONS

High rates of new HCV infection were found in this prisoner cohort reflecting their substantive risk behavior profile, despite having remained uninfected for many years. The association with MMT is challenging and highlights the need for better understanding of prison-specific HCV transmission risks, as well as the uptake and effectiveness of prevention programs.

European guideline for the management of hepatitis B and C virus infections, 2010

These are the guidelines on hepatitis B and C management for IUSTI/WHO in Europe, 2010. They describe the epidemiology, diagnosis, clinical features, treatment and prevention of hepatitis B and C with particular reference to sexual health clinical practice.

Evidence for the effectiveness of sterile injecting equipment provision in preventing hepatitis C and human immunodeficiency virus transmission among injecting drug users: a review of reviews

AIMS

To review the evidence on the effectiveness of harm reduction interventions involving the provision of sterile injecting equipment in the prevention of hepatitis C virus (HCV) and human immunodeficiency virus (HIV) transmission among injecting drug users (IDUs). The interventions assessed were needle and syringe programmes (NSP), alternative modes of needle/syringe provision (pharmacies, vending machines and outreach) and the provision of injecting equipment other than needles/syringes.

METHODS

Systematic searches of the English language literature to March 2007 were undertaken to identify systematic, narrative or meta-analytical reviews (also known as a review of reviews) of the impact of interventions on HCV transmission, HIV transmission or injecting risk behaviour (IRB). Critical appraisal criteria classified the reviews as either high quality ('core') or supplementary: a framework based on the quality of reviews, the reviewers' conclusions and the designs/findings of the primary studies was used to derive evidence statements.

RESULTS

Three core and two supplementary reviews of injecting equipment interventions were identified. According to the proposed framework, this study found (a) insufficient evidence to conclude that any of the interventions are effective in preventing HCV transmission; (b) tentative evidence to support the effectiveness of NSP in preventing HIV transmission; (c) sufficient evidence to support the effectiveness of NSP (and tentative evidence of an additional impact of pharmacy NSP) in reducing self-reported IRB; and (d) little to no evidence on vending machines, outreach or providing other injecting equipment in relation to any of the outcomes.

CONCLUSIONS

The evidence is weaker than given credit for in the literature. The lack of evidence for effectiveness of NSP vis-à-vis biological outcomes (HCV and HIV incidence/prevalence) reflects the limitations of studies that have been undertaken to investigate these associations. Particularly for HCV, low levels of IRB may be insufficient to reduce high levels of transmission. New studies are required to identify the intervention coverage necessary to achieve sustained changes in blood-borne virus transmission.

Longitudinal observation of a sample of German drug consumption facility clients

INTRODUCTION

We aimed at investigating whether attendance of a drug consumption facility (DCF) was associated with both a reduction of drug-associated at-risk behavior and referral to the health care treatment system.

METHODS

A sample of 129 consecutive clients out of those 256 who self-referred to the DCF during the 13-month observation period (i.e., from November 2002 to December 2003) was interviewed both at baseline and at 1-, 2-, 3-, and 6-month follow-ups. Subjects were repeatedly assessed using a structured approach based on both the European Addiction Severity Index (EuropASI) and the Deutsche Gesellschaft fuer Suchtforschung und Therapie (DG-Sucht).

RESULTS

Typical DCF clients were males, in their early 30s, single, with no vocational training, and with a long history of injectable opiate addiction in the context of polydrug misuse. A recent discharge from prison was recorded in 37% of cases. Median length of DCF attendance was of 5 weeks; 22% of clients attended for less than 1 week. Although with respect to the period previous to recruitment at-risk behavior rates remained unchanged, by the 3-month follow-up 13 (10%) clients out of those 129 who had initially enrolled had taken advantage of the DCF counseling opportunities. Some 37% of clients were referred on to start a methadone treatment following their DCF experience.

DISCUSSION

DCF attendance was not associated with reduction in at-risk behavior over time, but a need was here identified for additional intervention to be available in the DCF to address clients' psychosocial issues. Limitations of the present study include both issues related to the representativeness of the sample of clients here recruited and the lack of a control/comparison group.

The influence of needle exchange programs on injection risk behaviors and infection with hepatitis C virus among young injection drug users in select cities in the United States, 1994-2004

OBJECTIVE

Our purpose was to assess whether participation in needle exchange programs (NEPs) influenced incident hepatitis C virus (HCV) infection through effects on injection risk behaviors among young injection drug users (IDUs) in the United States.

METHODS

Data were drawn from three multi-site studies carried out in four major cities that enrolled IDUs over the period 1994-2004. Bivariate and multivariate analyses were conducted to assess relationships among sociodemographic characteristics, NEP use, injection risk behaviors, and prevalent or incident HCV infection.

RESULTS

Of the total participants (n=4663), HCV seroprevalence was 37%; among those who initially tested negative and completed follow-up at three, six, or 12 months (n=1288), 12% seroconverted. Nearly half of participants reported NEP (46%) use at baseline. Multivariate results showed no significant relationship between NEP use and HCV seroconversion. Controlling for sociodemographic characteristics, IDUs reporting NEP use were significantly less likely to share needles (aOR=0.77, 95% CI=0.67-0.88). Additionally, controlling for sociodemographic characteristics and program use, sharing needles, sharing other injection paraphernalia, longer injection duration, and injecting daily were all positively related to prevalent infection.

CONCLUSIONS

Our results suggest an indirect protective effect of NEP use on HCV infection by reducing risk behavior.

A national cross-sectional study among drug-users in France: epidemiology of HCV and highlight on practical and statistical aspects of the design

Background

Epidemiology of HCV infection among drug users (DUs) has been widely studied. Prevalence and sociobehavioural data among DUs are therefore available in most countries but no study has taken into account in the sampling weights one important aspect of the way of life of DUs, namely that they can use one or more specialized services during the study period. In 2004–2005, we conducted a national seroepidemiologic survey of DUs, based on a random sampling design using the Generalised Weight Share Method (GWSM) and on blood testing.

Methods

A cross-sectional multicenter survey was done among DUs having injected or snorted drugs at least once in their life. We conducted a two stage random survey of DUs selected to represent the diversity of drug use. The fact that DUs can use more than one structure during the study period has an impact on their inclusion probabilities. To calculate a correct sampling weight, we used the GWSM. A sociobehavioral questionnaire was administered by interviewers. Selected DUs were asked to self-collect a fingerprick blood sample on blotting paper.

Results

Of all DUs selected, 1462 (75%) accepted to participate. HCV seroprevalence was 59.8% [95% CI: 50.7–68.3]. Of DUs under 30 years, 28% were HCV seropositive. Of HCV-infected DUs, 27% were unaware of their status. In the month prior to interview, 13% of DUs shared a syringe, 38% other injection parapharnelia and 81% shared a crack pipe. In multivariate analysis, factors independently associated with HCV seropositivity were age over 30, HIV seropositivity, having ever injected drugs, opiate substitution treatment (OST), crack use, and precarious housing.

Conclusion

This is the first time that blood testing combined to GWSM is applied to a DUs population, which improve the estimate of HCV prevalence. HCV seroprevalence is high, indeed by the youngest DUs. And a large proportion of DUs are not aware of their status. Our multivariate analysis identifies risk factors such as crack consumption and unstable housing.

Incidence of hepatitis C in drug injectors: the role of homelessness, opiate substitution treatment, equipment sharing, and community size

A prospective cohort study estimated the incidence of hepatitis C virus (HCV) in drug injectors in South Wales (UK). In total, 286/481 eligible seronegative individuals were followed up after approximately 12 months. Dried blood spot samples were collected and tested for anti-HCV antibody and behavioural data were collected at baseline and follow-up. HCV incidence was 5.9/100 person-years [95% confidence interval (CI) 3.4-9.5]. HCV incidence was predicted by community size [incident rate ratio (IRR) 6.6, 95% CI 2.11-20.51, P = 0.001], homelessness (IRR 2.9, 95% CI 1.02-8.28, P = 0.047) and sharing injecting equipment (IRR 12.7, 95% CI 1.62-99.6, P = 0.015). HCV incidence was reduced in individuals in opiate substitution treatment (IRR 0.34, 95% CI 0.12-0.99, P = 0.047). In order to reduce follow-up bias we used multiple imputation of missing data using switching regression; after imputation estimated HCV incidence was 8.5/100 person-years (95% CI 5.4-12.7). HCV incidence varies with community size, equipment sharing and homelessness are associated with increased HCV incidence and opiate substitution treatment may be protective against HCV.

Epidemiological and genetic analyses of Hepatitis C virus transmission among young/short- and long-term injecting drug users from Rio de Janeiro, Brazil

BACKGROUND

Injecting drug users (IDU) have a key role in Hepatitis C Virus (HCV) epidemiology. Young/short-term IDUs constitute a target group for preventive/harm reduction interventions.

OBJECTIVES

To investigate HCV transmission among young/short-term (ST) and long-term (LT) IDUs, from the perspective of epidemiology and molecular biology.

STUDY DESIGN

Cross-sectional study assessing the prevalence of HCV infection/genotypes, as well as risk behaviours/practices among IDUs from Rio de Janeiro. Phylogenetic analyses were performed and the extent of segregation between sequences was quantified by the Association Index.

RESULTS

ST were more likely to engage into needle-sharing (p=.021) and LT to attend Needle Exchange Programs (p=.006). HCV prevalence was 10.1% vs. 23.4% among initiates and LT, respectively (p<.001). Older age vs. imprisonment and longer duration of IDU career were independent predictors for HCV infection among ST and LT, respectively. Among the latter, NEP attendance was inversely associated with viral infection. HCV3a infections were the most prevalent. A moderate extent of phylogenetic segregation between sequences was found, suggestive of transmission between IDU subgroups.

CONCLUSIONS

The lower HCV prevalence among young/short-term IDUs cannot be viewed with complacency, due to their frequent engagement into direct/indirect sharing practices and the ongoing transmission between IDU subsets. To avert new infections, preventive/harm reduction policies must be tailored to empirical findings.

[Prevention of hepatitis C virus infection in drug users]

The high prevalence and incidence rates of the hepatitis C virus (HCV) infections in drug users demonstrate the urgent necessity for a coordinated national prevention strategy. In the shadow of HIV/AIDS the necessary attention to the rapid spreading of the hepatitis C in drug users was started late, without being able to reach the public attention level of HIV/AIDS. The present efforts in the primary and secondary prevention of the hepatitis C in drug users are obviously not sufficient to reduce the prevalence with long-lasting results. Substitution treatment is of central relevance in the prevention of hepatitis C in opiate-dependent subjects, but requires, as current data of the HCV incidence of substituted opiate dependents illustrate, a stronger HCV-specific accentuation. Further settings, which are relevant for the group of intravenous drug users, have to be accessed and sensitized. Furthermore structural and political efforts are necessary, in order to develop a systematic and evidence-based answer to the challenge of the HCV spreading in drug users, in particular due to the fact that a German HCV strategy is still lacking.

The effectiveness of behavioural interventions in the primary prevention of hepatitis C amongst injecting drug users: a randomised controlled trial and lessons learned

AIM

To develop and evaluate the comparative effectiveness of behavioural interventions of enhanced prevention counselling (EPC) and simple educational counselling (SEC) in reducing hepatitis C viral (HCV) infection in sero-negative injecting drug users (IDU).

DESIGN

Randomised controlled trial (RCT) of EPC intervention in comparison with simple educational counselling (SEC). SETTING SPECIALISED: Drug services in London and Surrey, United Kingdom.

PARTICIPANTS AND MEASUREMENTS

Ninety five IDUs were recruited and randomised to receive EPC (n = 43) or SEC (n = 52). Subjects were assessed at baseline using the Addiction Severity Index (ASI), the Injecting Risk Questionnaire (IRQ), and Drug Injecting Confidence Questionnaire (DICQ). The primary outcome was measured by the rate of sero-conversion at 6 months and 12 months from baseline and by the ASI, IRQ and DICQ at 6 months from baseline. Hepatitis C testing was undertaken by the innovative test of the dried blood spot (DBS) test which increased the rate of testing by 4 fold compared to routine blood testing. FINDINGS SEVENTY: Eighty two subjects (82%) out of the 95 recruited were followed up at 6 months and 62 (65%) were followed up at 12 months. On the primary outcome measure of the rate of seroconversion, 8 out of 62 patients followed-up at twelve months seroconverted, three in the EPC group and five in the SEC group, indicating incidence rates of 9.1 per 100 person years for the EPC group, 17.2 per 100 person years for the SEC group, and 12.9 per 100 person years for the cohort as a whole. Analysis of the secondary outcome measures on alcohol use, risk behaviour, psychological measures, quality of life, showed no significant differences between the EPC and the SEC groups. However, there were significant changes on a number of measures from baseline values indicating positive change for both groups.

CONCLUSION

We were not able to prove the efficacy of EPC in comparison with SEC in the prevention of hepatitis C in IDUs. This was related to low recruitment and retention rates of the participants. Moreover there was a low adherence rate to EPC. The study provided the benefits of developing and introducing behavioural interventions of the EPC and SEC and the DBS screening for Hepatitis C. Moreover the main lessons learnt were that piloting of a new intervention is a crucial first step before conducting pragmatic RCTs of psychological interventions in the field of addiction; that an infrastructure and culture for psychosocial interventions is needed to enable applied research in the service environment, and research funding is needed for enabling the recruitment of dedicated trained therapists for the delivery of these interventions.

Hepatitis C and human immunodeficiency virus risk behaviors in polydrug users on methadone maintenance

We examined the impact of methadone maintenance treatment (MMT) on risk behaviors for transmission of blood-borne diseases in polydrug users who had tested positive or negative for hepatitis C virus (HCV). At intake, HCV-positive participants (n=362) engaged in more human immunodeficiency virus (HIV) risk behaviors (as measured by the HIV Risk-Taking Behavior Scale) than HCV-negative participants (n=297; p< .001). This difference was specific to injection-related behaviors and decreased significantly within the first few weeks of MMT (p< .0001). Where needles continued to be used, HCV-positive participants became more likely over time to engage in safer injecting practices. Furthermore, HCV-positive participants became more likely to use condoms than HCV-negative participants. These findings demonstrate that both drug- and sex-related risk behaviors decrease during MMT and emphasize the benefits of methadone programs for public health and HIV/HCV prevention.

Controversies in and challenges to our understanding of hepatitis C

Discovered in 1989, the hepatitis C virus (HCV) continues to cause significant morbidity and mortality world-wide despite a huge research commitment to defining and understanding the virus and the disease it causes. This paper discusses a number of areas where progress in the management of the HCV have not kept pace with the scientific understanding of the HCV. It is suggested that in the fields of HCV prevention and providing access to treatment, practice falls short of what could be achieved. The role of alcohol in the pathogenesis of HCV liver injury is discussed. Discrimination against those with HCV infection and particularly those in prison settings fails to match good clinical practice. The complicated processes of sharing information between specialty groups is also discussed in an attempt to optimise knowledge dissemination in this field.