Opioid substitution therapy protects against hepatitis C virus acquisition in people who inject drugs: the HITS-c study

Importance and Contribution of Community, Social, and Healthcare Risk Factors for Hepatitis C Infection in Pakistan

Pakistan has a high prevalence of hepatitis C virus (HCV) infection, estimated at 4.9% (2,290/46,843) in the 2007 national HCV seroprevalence survey. We used data from this survey to assess the importance of risk factor associations with HCV prevalence in Pakistan. Exposures were grouped as community (going to the barbers, sharing smoking equipment, having an ear/nose piercing, tattoo, or acupuncture), healthcare (ever having hemodialysis, blood transfusion, or ≥ 5 injections in the last year), demographic (marital status and age), and socio-economic (illiterate or laborer). We used mutually adjusted multivariable regression analysis, stratified by sex, to determine associations with HCV infection, their population attributable fraction, and how risk of infection accumulates with multiple exposures. Strength of associations was assessed using adjusted odds ratios (aOR). Community [aOR females 1.5 (95% confidence interval [CI]: 1.2, 1.8); males 1.2 (1.1, 1.4)] and healthcare [females 1.4 (1.2, 1.6); males 1.2 (1.1, 1.4)] exposures, low socio-economic status [females 1.6 (1.3, 1.80); males 1.3 (1.2, 1.5)], and marriage [females 1.5 (1.2, 1.9); males 1.4 (1.1, 1.8)] were associated with increased HCV infection. Among married women, the number of children was associated with an increase in HCV infection; linear trend aOR per child 1.06 (1.01, 1.11). Fewer infections could be attributed to healthcare exposures (females 13%; males 6%) than to community exposures (females 25%; males 9%). Prevalence increased from 3% to 10% when cumulative exposures increased from 1 to ≥ 4 [aOR per additional exposure for females 1.5 (1.4, 1.6); males 1.2 (1.2, 1.3)]. A combination of community, healthcare, and other factors appear to drive the Pakistan HCV epidemic, highlighting the need for a comprehensive array of prevention strategies.

Needle syringe programmes and opioid substitution therapy for preventing hepatitis C transmission in people who inject drugs

BACKGROUND

Needle syringe programmes and opioid substitution therapy for preventing hepatitis C transmission in people who inject drugsNeedle syringe programmes (NSP) and opioid substitution therapy (OST) are the primary interventions to reduce hepatitis C (HCV) transmission in people who inject drugs. There is good evidence for the effectiveness of NSP and OST in reducing injecting risk behaviour and increasing evidence for the effectiveness of OST and NSP in reducing HIV acquisition risk, but the evidence on the effectiveness of NSP and OST for preventing HCV acquisition is weak.

OBJECTIVES

To assess the effects of needle syringe programmes and opioid substitution therapy, alone or in combination, for preventing acquisition of HCV in people who inject drugs.

SEARCH METHODS

We searched the Cochrane Drug and Alcohol Register, CENTRAL, the Cochrane Database of Systematic Reviews (CDSR), the Database of Abstracts of Reviews of Effects (DARE), the Health Technology Assessment Database (HTA), the NHS Economic Evaluation Database (NHSEED), MEDLINE, Embase, PsycINFO, Global Health, CINAHL, and the Web of Science up to 16 November 2015. We updated this search in March 2017, but we have not incorporated these results into the review yet. Where observational studies did not report any outcome measure, we asked authors to provide unpublished data. We searched publications of key international agencies and conference abstracts. We reviewed reference lists of all included articles and topic-related systematic reviews for eligible papers.

SELECTION CRITERIA

We included prospective and retrospective cohort studies, cross-sectional surveys, case-control studies and randomised controlled trials that measured exposure to NSP and/or OST against no intervention or a reduced exposure and reported HCV incidence as an outcome in people who inject drugs. We defined interventions as current OST (within previous 6 months), lifetime use of OST and high NSP coverage (regular attendance at an NSP or all injections covered by a new needle/syringe) or low NSP coverage (irregular attendance at an NSP or less than 100% of injections covered by a new needle/syringe) compared with no intervention or reduced exposure.

DATA COLLECTION AND ANALYSIS

We followed the standard Cochrane methodological procedures incorporating new methods for classifying risk of bias for observational studies. We described study methods against the following 'Risk of bias' domains: confounding, selection bias, measurement of interventions, departures from intervention, missing data, measurement of outcomes, selection of reported results; and we assigned a judgment (low, moderate, serious, critical, unclear) for each criterion.

MAIN RESULTS

We identified 28 studies (21 published, 7 unpublished): 13 from North America, 5 from the UK, 4 from continental Europe, 5 from Australia and 1 from China, comprising 1817 incident HCV infections and 8806.95 person-years of follow-up. HCV incidence ranged from 0.09 cases to 42 cases per 100 person-years across the studies. We judged only two studies to be at moderate overall risk of bias, while 17 were at serious risk and 7 were at critical risk; for two unpublished datasets there was insufficient information to assess bias. As none of the intervention effects were generated from RCT evidence, we typically categorised quality as low. We found evidence that current OST reduces the risk of HCV acquisition by 50% (risk ratio (RR) 0.50, 95% confidence interval (CI) 0.40 to 0.63, I2 = 0%, 12 studies across all regions, N = 6361), but the quality of the evidence was low. The intervention effect remained significant in sensitivity analyses that excluded unpublished datasets and papers judged to be at critical risk of bias. We found evidence of differential impact by proportion of female participants in the sample, but not geographical region of study, the main drug used, or history of homelessness or imprisonment among study samples.Overall, we found very low-quality evidence that high NSP coverage did not reduce risk of HCV acquisition (RR 0.79, 95% CI 0.39 to 1.61) with high heterogeneity (I2 = 77%) based on five studies from North America and Europe involving 3530 participants. After stratification by region, high NSP coverage in Europe was associated with a 76% reduction in HCV acquisition risk (RR 0.24, 95% CI 0.09 to 0.62) with less heterogeneity (I2 =0%). We found low-quality evidence of the impact of combined high coverage of NSP and OST, from three studies involving 3241 participants, resulting in a 74% reduction in the risk of HCV acquisition (RR 0.26 95% CI 0.07 to 0.89).

AUTHORS' CONCLUSIONS

OST is associated with a reduction in the risk of HCV acquisition, which is strengthened in studies that assess the combination of OST and NSP. There was greater heterogeneity between studies and weaker evidence for the impact of NSP on HCV acquisition. High NSP coverage was associated with a reduction in the risk of HCV acquisition in studies in Europe.

Utilization of buprenorphine and methadone among opioid users who inject drugs

BACKGROUND

There has been a rise in opioid abuse and related injection drug use in the United States, and treatment for opioid use disorders may be underutilized. The study aim was to describe utilization of opioid agonist therapy (OAT), and assess factors associated with utilization of OAT, among persons who inject drugs (PWID) in the Seattle metropolitan area.

METHODS

Data were obtained from the 2015 National HIV Behavioral Surveillance (NHBS) system among PWID in the Seattle area. Persons aged ≥18 years who injected drugs in the past year were recruited using respondent-driven sampling. Local supplemental questions assessed whether participants had received methadone or buprenorphine treatment in the past year. The analysis was restricted to participants who reported use of any opioids in the past year. Analyses compared the demographic, health insurance status, duration of injection drug use, prior history of overdose, prior receipt of hepatitis C virus/human immunodeficiency virus (HCV/HIV) testing (self-report), and screening positive for HCV/HIV via study testing between methadone- or buprenorphine-treated and untreated PWID. Multivariate logistic models were performed to assess adjusted associations with receipt of any OAT.

RESULTS

The sample included 487 PWID who used opioids in the past year, of whom 27.1% (95% confidence interval [CI]: 23.1-31.1) reported past-year treatment with methadone and 4.7% (95% CI: 2.8-6.6) reported treatment with buprenorphine. There were no significant differences in demographics among participants who did and did not report past-year OAT; however, participants who were treated with methadone were more likely to be insured and have hepatitis C. After adjustment for other covariates, having health insurance was strongly associated with receipt of OAT (adjusted odds ratio [aOR] = 18.6; 95% CI: 2.5-138.7).

CONCLUSIONS

OAT, in particular buprenorphine, has been underutilized by opioid-using PWID in the Seattle area. Health insurance is a critical factor for enabling PWID to utilize OAT treatment for opioid use disorders.

Ongoing incident hepatitis C virus infection among people with a history of injecting drug use in an Australian prison setting, 2005-2014: The HITS-p study

Hepatitis C virus (HCV) transmission is high in prisons. This study investigated trends in HCV incidence and associated factors among a cohort of prisoners with a history of injecting drug use in New South Wales, Australia. Data were available from the Hepatitis C Incidence and Transmission Study-prisons (HITS-p) from 2005 to 2014. Temporal trends in HCV incidence were evaluated. Factors associated with time to HCV seroconversion among people with ongoing injecting was assessed using Cox proportional hazards. Among 320 antibody-negative participants with a history of injecting drug use (mean age 26; 72% male), 62% (n=197) reported injecting drug use during follow-up. Overall, 93 infections were observed. HCV incidence was 11.4/100 person-years in the overall population and 6.3/100 person-years among the continually imprisoned population. A stable trend in HCV incidence was observed. Among the overall population with ongoing injecting during follow-up, ≥weekly injecting drug use frequency was independently associated with time to HCV seroconversion. Among continuously imprisoned injectors with ongoing injecting during follow-up, needle/syringe sharing was independently associated with time to HCV seroconversion. This study demonstrates that prison is a high-risk environment for acquisition of HCV infection. Needle and syringe sharing was associated with HCV infection among continually imprisoned participants, irrespective of frequency of injecting or the type of drug injected. These findings highlight the need for the evaluation of improved HCV prevention strategies in prison, including needle/syringe programmes and HCV treatment.

Assessing the impact and cost-effectiveness of needle and syringe provision and opioid substitution therapy on hepatitis C transmission among people who inject drugs in the UK: an analysis of pooled data sets and economic modelling

Background

There is limited evidence of the impact of needle and syringe programmes (NSPs) and opioid substitution therapy (OST) on hepatitis C virus (HCV) incidence among people who inject drugs (PWID), nor have there been any economic evaluations.

Objective(s)

To measure (1) the impact of NSP and OST, (2) changes in the extent of provision of both interventions, and (3) costs and cost-effectiveness of NSPs on HCV infection transmission.

Design

We conducted (1) a systematic review; (2) an analysis of existing data sets, including collating costs of NSPs; and (3) a dynamic deterministic model to estimate the impact of differing OST/NSP intervention coverage levels for reducing HCV infection prevalence, incidence and disease burden, and incremental cost-effectiveness ratios to measure the cost-effectiveness of current NSP provision versus no provision.

Setting

Cost-effectiveness analysis and impact modelling in three UK sites. The pooled analysis drew on data from the UK and Australia. The review was international.

Participants

PWID.

Interventions

NSP coverage (proportion of injections covered by clean needles) and OST.

Outcome

New cases of HCV infection.

Results

The review suggested that OST reduced the risk of HCV infection acquisition by 50% [rate ratio (RR) 0.50, 95% confidence interval (CI) 0.40 to 0.63]. Weaker evidence was found in areas of high (≥ 100%) NSP coverage (RR 0.77, 95% CI 0.38 to 1.54) internationally. There was moderate evidence for combined high coverage of NSPs and OST (RR 0.29, 95% CI 0.13 to 0.65). The pooled analysis showed that combined high coverage of NSPs and OST reduced the risk of HCV infection acquisition by 29–71% compared with those on minimal harm reduction (no OST, ≤ 100% NSP coverage). NSPs are likely to be cost-effective and are cost-saving in some settings. The impact modelling suggest that removing OST (current coverage 81%) and NSPs (coverage 54%) in one site would increase HCV infection incidence by 329% [95% credible interval (CrI) 110% to 953%] in 2031 and at least double (132% increase; 95% CrI 51% to 306%) the number of new infections over 15 years. Increasing NSP coverage to 80% has the largest impact in the site with the lowest current NSP coverage (35%), resulting in a 27% (95% CrI 7% to 43%) decrease in new infections and 41% (95% CrI 11% to 72%) decrease in incidence by 2031 compared with 2016. Addressing homelessness and reducing the harm associated with the injection of crack cocaine could avert approximately 60% of HCV infections over the next 15 years.

Limitations

Findings are limited by the misclassification of NSP coverage and the simplified intervention definition that fails to capture the integrated services that address other social and health needs as part of this.

Conclusions

There is moderate evidence of the effectiveness of OST and NSPs, especially in combination, on HCV infection acquisition risk. Policies to ensure that NSPs can be accessed alongside OST are needed. NSPs are cost-saving in some sites and cost-effective in others. NSPs and OST are likely to prevent considerable rates of HCV infection in the UK. Increasing NSP coverage will have most impact in settings with low coverage. Scaling up other interventions such as HCV infection treatment are needed to decrease epidemics to low levels in higher prevalence settings.

Future work

To understand the mechanisms through which NSPs and OST achieve their effect and the optimum contexts to support implementation.

Funding

The National Institute for Health Research Public Health Research programme.

Injecting drug use in low and middle-income countries: Opportunities to improve care and prevent harm

Inadequate response to injecting drug use (IDU) is a significant problem the world over. Low levels of funding, political inaction, poor levels of health service coverage, high prevalence and incidence of IDU-related blood-borne viruses (BBVs) and ongoing stigmatization/marginalization affect people who inject drugs (PWID) regardless of the income status of the country they reside in. These barriers and system failings are, however, exacerbated in low and middle-income countries (LMICs), meaning that the potential consequences of inaction are more pressing. In this narrative review, we describe the levels of IDU and IDU-specific BBV prevalence in LMICs; levels of harm reduction implementation; the consequences of late or insufficient response, the shortcomings of data collection and dissemination; and the barriers to effective LMIC harm reduction implementation. We also exemplify cases where IDU-related harms and BBV epidemics have been successfully curtailed in LMICs, showing that effective response, despite the barriers, is possible. In conclusion, we suggest four key priorities on the basis of the review: confirming the presence or absence of IDU in LMICs, improving the collection and dissemination of national IDU-specific data, increasing the level of harm reduction programme implementation in LMICs, and increasing both national and international advocacy for PWID and attendant public health interventions.

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

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

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

INTRODUCTION

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

DISCUSSION

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

CONCLUSIONS

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

High hepatitis C incidence in relation to prescription opioid injection and poly-drug use: Assessing barriers to hepatitis C prevention

BACKGROUND

Prescription opioid (PO) injection and poly-drug use have been associated with hepatitis C virus (HCV) infection among people who inject drugs (PWID). Poly-drug use is often a barrier to key HCV preventive programmes including opioid agonist treatment. The contribution of specific drug combinations to high HCV incidence in poly-drug users has not been assessed previously. Addressing this knowledge gap could enhance HCV treatment and prevention efforts. We examined the association between specific drugs and number of drugs used in addition to injected POs, and HCV seroconversion.

METHODS

PWID participating in a cohort study in Montréal (HEPCO), HCV-seronegative at baseline and followed between 2004 and 2013, were included. Data were collected by interview-administered questionnaires. Blood samples were tested for HCV new infections at each 3-6 month follow-up visit. Time-varying Cox regression models were utilized.

RESULTS

Of 356 participants (81.5% males; mean age: 34.7 years), 123 (34.6%) reported injected POs in the past month at baseline. In univariate analyses, recent use of the following drugs was associated with HCV seroconversion: injected POs, injected cocaine, injected heroin, non-injected tranquilisers, and smoked crack/cocaine. The relative excess risk of HCV seroconversion due to interaction (RER1_HR) was the highest for co-use of injected POs with the following substances: injected cocaine (RER1_HR=3.44), smoked crack/cocaine (RER1_HR=1.27), and non-injected tranquilisers (RER1_HR=0.8). In addition, a significant linear trend (p<0.001) towards higher risk was observed with increasing the number of these three drugs used in combination with injected POs.

CONCLUSION

Specific drugs and number of drugs used in addition to injected POs play a modulating role in the risk of HCV primary infection. Poly-drug use among people who inject POs has to be addressed in order to improve harm reduction programmes and reduce HCV transmission in this high-risk population.

A molecular transmission network of recent hepatitis C infection in people with and without HIV: Implications for targeted treatment strategies

Combining phylogenetic and network methodologies has the potential to better inform targeted interventions to prevent and treat infectious diseases. This study reconstructed a molecular transmission network for people with recent hepatitis C virus (HCV) infection and modelled the impact of targeting directly acting antiviral (DAA) treatment for HCV in the network. Participants were selected from three Australian studies of recent HCV from 2004 to 2014. HCV sequence data (Core-E2) from participants at the time of recent HCV detection were analysed to infer a network by connecting pairs of sequences whose divergence was ≤.03 substitutions/site. Logistic regression was used to identify factors associated with connectivity. Impact of targeting HCV DAAs at both HIV co-infected and random nodes was simulated (1 million replicates). Among 236 participants, 21% (n=49) were connected in the network. HCV/HIV co-infected participants (47%) were more likely to be connected compared to HCV mono-infected participants (16%) (OR 4.56; 95% CI; 2.13-9.74). Simulations targeting DAA HCV treatment to HCV/HIV co-infected individuals prevented 2.5 times more onward infections than providing DAAs to randomly selected individuals. Results demonstrate that genetic distance-based network analyses can be used to identify characteristics associated with HCV transmission, informing targeted prevention and treatment strategies.

HCV reinfection incidence among individuals treated for recent infection

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

Geographic Differences in Temporal Incidence Trends of Hepatitis C Virus Infection Among People Who Inject Drugs: The InC3 Collaboration

BACKGROUND

We determined temporal trends (1985-2011) in hepatitis C virus (HCV) incidence and associated behavioral exposures for people who inject drugs (PWID) from the United States (Boston, Baltimore, and San Francisco), Canada (Montreal), the Netherlands (Amsterdam), and Australia (Sydney and Melbourne).

METHODS

Using population-based cohort data from HCV-negative PWID, we calculated overall and within-city HCV incidence trends, HCV rates by study enrollment period (1985-2011), and temporal trends in exposure behaviors. Poisson regression models estimated trends in HCV incidence over calendar-time. Survival models identified risk factors for HCV incidence across cities and estimated independent effects of city and calendar period on HCV infection risk.

RESULTS

Among 1391 initially HCV-negative participants followed prospectively (1644.5 person-years of observation [PYO]), 371 HCV incident infections resulted in an overall incidence of 22.6 per 100 PYO (95% confidence interval [CI], 20.4-25.0). Incidence was highest and remained elevated in Baltimore (32.6/100 PYO), San Francisco (24.7/100 PYO), and Montreal (23.5/100 PYO), lowest in Melbourne and Amsterdam (7.5/100 PYO and 13.1/100 PYO, respectively), and moderate (21.4/100 PYO) in Sydney. Higher rates of syringe and equipment sharing and lower prevalence of opioid agonist therapy were associated with HCV incidence in cities with the highest incidence. Risk for infection dropped by 18% for every 3-year increase in calendar-time (adjusted hazard ratio, 0.8 [95% CI, .8-.9]) in the multivariable model.

CONCLUSIONS

Differences in prevention strategies and injecting contexts may explain the ongoing high HCV incidence in these North American cities and emphasize the need for scale-up of opioid agonist therapy and increased coverage of needle and syringe programs in North America.

Pharmaceutical opioid use among oral and intravenous users in Australia: A qualitative comparative study

BACKGROUND

Between 1992 and 2012 dispensing episodes for pharmaceutical opioids (PO) in Australia increased from 500000 to 7500000. In the US, increases in the prescription of PO have been linked to increases in opioid-related morbidity and mortality and transitions to heroin injection. However, Australian data indicate that morbidity and mortality related to PO are relatively low, particularly when compared to heroin and other drugs. This paper explores the characteristics and patterns of non-medical pharmaceutical opioid (NMPO) use among a sample of young people in Sydney, Australia.

METHODS

During 2015, we conducted in-depth qualitative interviews with 34 young people who use PO non-medically by oral (n=22) and intravenous (n=12) routes of administration.

RESULTS

Oral NMPO users were a more affluent group who clustered around the Northern, Inner and Eastern suburbs of Sydney, while the intravenous users came from a range of locations including rural/regional areas of NSW and socioeconomically disadvantaged suburbs of South Western Sydney. Oral users were characterised by intermittent and largely self-limiting NMPO use and reported few health and social consequences. Intravenous users reported heavy and frequent drug, including NMPO, use and a range of adverse health and social consequences including overdose, injecting risk behaviour, hepatitis C virus (HCV) infection and residential instability.

CONCLUSION

Results highlight the significance of social and structural factors in trajectories of opioid use and related harms. Factors such as stable housing and family relationships, disposable income and close social networks observed in young oral NMPO users may help to explain differences in patterns of NMPO use and related outcomes between the two groups.

The effects of needle-sharing and opioid substitution therapy on incidence of hepatitis C virus infection and reinfection in people who inject drugs

Although high hepatitis C virus (HCV) prevalence has been observed in people who inject drugs (PWID) for decades, research suggests incidence is falling. We examined whether PWIDs' use of opioid substitution therapy (OST) and their needle-and-syringe sharing behaviour explained HCV incidence. We assessed HCV incidence in 235 PWID in Melbourne, Australia, and performed discrete-time survival with needle-sharing and OST status as independent variables. HCV infection, reinfection and combined infection/reinfection incidences were 7·6 [95% confidence interval (CI) 4·8-11·9], 12·4 (95% CI 9·1-17·0) and 9·7 (95% CI 7·4-12·6) per 100 person-years, respectively. Needle-sharing was significantly associated with higher incidence of naive HCV infection [hazard ratio (HR) 4·9, 95% CI 1·3-17·7] but not reinfection (HR 1·85, 95% CI 0·79-4·32); however, a cross-model test suggested this difference was sample specific. Past month use of OST had non-significant protective effects against naive HCV infection and reinfection. Our data confirm previous evidence of greatly reduced HCV incidence in PWID, but not the significant protective effect of OST on HCV incidence detected in recent studies. Our findings reinforce the need for greater access to HCV testing and prevention services to accelerate the decline in incidence, and HCV treatment, management and support to limit reinfection.

Hepatitis C-specific effector and regulatory CD4 T-cell responses are associated with the outcomes of primary infection

Clearance of primary hepatitis C virus (HCV) infection has been associated with strong and broadly targeted cellular immune responses. This study aimed to characterize HCV-specific CD4+ effector and regulatory T-cell numbers and cytokine production during primary infection. Antigen-specific CD4+ T-cell responses were investigated in a longitudinal cohort of subjects from pre-infection to postoutcome, including subjects who cleared [n=12] or became chronically infected [n=17]. A cross-sectional cohort with previously cleared, or chronic infection [n=15 for each], was also studied. Peripheral blood mononuclear cells were incubated with HCV antigens and surface stained for T-effector (CD4+CD25^high CD134+CD39-) and T-regulatory (CD4+CD25^high CD134+CD39+) markers, and culture supernatants assayed for cytokine production. Contrary to expectations, the breadth and magnitude of the HCV-specific CD4+ T-cell responses were higher in subjects who became chronically infected. Subjects who cleared the virus had HCV-specific CD4+ T-cell responses dominated by effector T cells and produced higher levels of IFN-γ, in contrast to HCV-specific CD4+ T-cell responses dominated by regulatory T cells and more IL-10 production in those who became chronically infected. Better understanding of the role of antigen-specific CD4+ T-cell responses in primary HCV will further define pathogenesis and help guide development of a preventative vaccine.

Individual-level needle and syringe coverage in Melbourne, Australia: a longitudinal, descriptive analysis

Background

Coverage is used as one indicator of needle and syringe program (NSP) effectiveness. At the individual level, coverage is typically defined as an estimate of the proportion of a person who injects drugs’ (PWID) injecting episodes that utilise a sterile syringe. In this paper, we explore levels of individual syringe coverage and its changes over time.

Methods

Data were extracted from 1889 interviews involving 502 participants drawn from the Melbourne drug user cohort study (MIX).

We asked questions relating to participants syringe acquisition, distribution and injecting frequency within the two weeks before interview. We created a dichotomous coverage variable that classified participants as sufficiently (≥100 %) covered if all their injecting episodes utilised at least one sterile syringe, and insufficiently (<100 %) covered if not. We categorised participants as “consistently covered” if they were sufficiently covered across interviews; as “consistently uncovered” if they were insufficiently covered across interviews; and “inconsistently covered” if they oscillated between coverage states.

Chi-square statistics tested proportions of insufficient coverage across sub-groups using broad demographic, drug use and service utilisation domains. Logistic regression tested predictors of insufficient coverage and inconsistently covered categorisation.

Results

Across the sample, levels of insufficient coverage were substantial (between 22–36 % at each interview wave). The majority (50 %) were consistently covered across interviews, though many (45 %) were inconsistently covered.

We found strong statistical associations between insufficient coverage and current hepatitis C virus (HCV) infection (RNA+). Current prescription of opioid substitution therapy (OST) and using NSPs as the main source of syringe acquisition were protective against insufficient coverage.

Conclusion

Insufficient coverage across the sample was substantial and mainly driven by those who oscillated between states of coverage, suggesting the presence of temporal factors. We recommend a general expansion of NSP services and OST prescription to encourage increases in syringe coverage.

Electronic supplementary material

The online version of this article (doi:10.1186/s12913-016-1668-z) contains supplementary material, which is available to authorized users.

Harm Reduction: Front Line Public Health

Drug use is a public health problem associated with high mortality and morbidity, and is often accompanied by suboptimal engagement in health care. Harm reduction is a pragmatic public health approach encompassing all goals of public health: improving health, social well-being, and quality of life. Harm reduction prioritizes improving the lives of people who use drugs in partnership with those served without a narrow focus on abstinence from drugs. Evidence has shown that harm reduction oriented practice can reduce transmission of blood-borne illnesses, and other injection related infections, as well as preventing fatal overdose.

Impact of Medication-Assisted Treatment for Opioid Addiction on Medicaid Expenditures and Health Services Utilization Rates in Vermont

In the face of increasing rates of overdose deaths, escalating health care costs, and the tremendous social costs of opioid addiction, policy makers are asked to address the questions of whether and how to expand access to treatment services. In response to an upward trend in opioid abuse and adverse outcomes, Vermont is investing in statewide expansion of a medication-assisted therapy program delivered in a network of community practices and specialized treatment centers (Hub & Spoke Program). This study was conducted to test the rationale for these investments and to establish a pre-Hub & Spoke baseline for evaluating the additive impact of the program. Using a serial cross-sectional design from 2008 to 2013 to evaluate medical claims for Vermont Medicaid beneficiaries with opioid dependence or addiction (6158 in the intervention group, 2494 in the control group), this study assesses the treatment and medical service expenditures for those receiving medication-assisted treatment compared to those receiving substance abuse treatment without medication. Results suggest that medication-assisted therapy is associated with reduced general health care expenditures and utilization, such as inpatient hospital admissions and outpatient emergency department visits, for Medicaid beneficiaries with opioid addiction. For state Medicaid leaders facing similar decisions on approaches to opioid addiction, these results provide early support for expanding medication-assisted treatment services rather than relying only on psychosocial, abstinence, or detoxification interventions.

'Crisis' and 'everyday' initiators: A qualitative study of coercion and agency in the context of methadone maintenance treatment initiation

INTRODUCTION AND AIMS

Patient attrition is common among people enrolled in methadone maintenance treatment (MMT) programs and most pronounced during the first year of treatment. However, the experiences of patients initiating MMT have been overlooked in the literature. This study explores experiences of MMT initiation among MMT patients, focusing on contextual influences on MMT initiation and perceptions of MMT and their subsequent influence on treatment retention.

DESIGN AND METHODS

Semi-structured qualitative interviews were conducted with 39 MMT patients in Vancouver, Canada. Individuals reporting enrolment in MMT were recruited from within two ongoing cohort studies comprised of people who use drugs. Interview transcripts were analysed using an inductive and iterative approach.

RESULTS

Two groups of MMT initiators were identified: (i) 'crisis initiators' prescribed methadone following critical transition events, such as incarceration or pregnancy; and (ii) 'everyday initiators' enrolled in MMT as part of routine healthcare utilisation. While most 'crisis initiators' and some 'everyday initiators' described experiencing coercion during MMT initiation, 'crisis initiators' were further subjected to the coercive leveraging of their vulnerability to motivate 'consent' for MMT. 'Crisis initiators' developed negative views towards MMT and were more likely to discontinue treatment. Long-standing patient-provider relationships and open dialogue were associated with more positive views regarding MMT, regardless of the circumstances of initiation.

DISCUSSION AND CONCLUSION

Findings underscore the need for clear and effective communication regarding treatment regimens and expectations during MMT initiation. Furthermore, training in trauma-informed care may help reduce perceptions of coercion and rates of early treatment termination. [Damon W, Small W, Anderson S, Maher L, Wood E, Kerr T, McNeil R. Crisis' and 'everyday' initiators: A qualitative study of coercion and agency in the context of methadone maintenance treatment initiation. Drug Alcohol Rev 2017;36:253-260].

Public health and international drug policy

In September 2015, the member states of the United Nations endorsed sustainable development goals (SDG) for 2030 that aspire to human rights-centered approaches to ensuring the health and well-being of all people. The SDGs embody both the UN Charter values of rights and justice for all and the responsibility of states to rely on the best scientific evidence as they seek to better humankind. In April 2016, these same states will consider control of illicit drugs, an area of social policy that has been fraught with controversy, seen as inconsistent with human rights norms, and for which scientific evidence and public health approaches have arguably played too limited a role.

The previous UN General Assembly Special Session (UNGASS) on drugs in 1998 – convened under the theme “a drug-free world, we can do it!” – endorsed drug control policies based on the goal of prohibiting all use, possession, production, and trafficking of illicit drugs. This goal is enshrined in national law in many countries. In pronouncing drugs a “grave threat to the health and well-being of all mankind,” the 1998 UNGASS echoed the foundational 1961 convention of the international drug control regime, which justified eliminating the “evil” of drugs in the name of “the health and welfare of mankind.” But neither of these international agreements refers to the ways in which pursuing drug prohibition itself might affect public health. The “war on drugs” and “zero-tolerance” policies that grew out of the prohibitionist consensus are now being challenged on multiple fronts, including their health, human rights, and development impact.

The Johns Hopkins – Lancet Commission on Drug Policy and Health has sought to examine the emerging scientific evidence on public health issues arising from drug control policy and to inform and encourage a central focus on public health evidence and outcomes in drug policy debates, such as the important deliberations of the 2016 UNGASS on drugs.

The Johns Hopkins-Lancet Commission is concerned that drug policies are often colored by ideas about drug use and drug dependence that are not scientifically grounded. The 1998 UNGASS declaration, for example, like the UN drug conventions and many national drug laws, does not distinguish between drug use and drug abuse. A 2015 report by the UN High Commissioner for Human Rights, by contrast, found it important to emphasize that “[d]rug use is neither a medical condition nor does it necessarily lead to drug dependence.” The idea that all drug use is dangerous and evil has led to enforcement-heavy policies and has made it difficult to see potentially dangerous drugs in the same light as potentially dangerous foods, tobacco, alcohol for which the goal of social policy is to reduce potential harms.

Benzodiazepine Use and Hepatitis C Seroconversion in a Cohort of Persons Who Inject Drugs

OBJECTIVES

To examine the relationship between benzodiazepine (BZD) use and HCV seroconversion in 2 linked prospective cohorts of persons who inject drugs (PWID).

METHODS

We examined prospective cohorts of 440 PWID (baseline BZD users: n = 102; 23.2%) from the AIDS Care Cohort to Evaluate Access to Survival Services (ACCESS) and the Vancouver Injection Drug Users Study (VIDUS) cohorts, followed-up from 1996 to 2013 in Vancouver, Canada.

RESULTS

At baseline, the prevalence of HCV was higher among those who used BZD (80.5% vs 61.5%; P < .001). After adjustment, BZD use remained independently associated with increased rates of HCV seroconversion (adjusted rate ratio = 1.67; 95% confidence interval = 1.05, 2.66).

CONCLUSIONS

BZD use is independently associated with HCV seroconversion in a population of PWID.

Transmission of Hepatitis C Virus among Prisoners, Australia, 2005-2012

Ongoing transmission is associated with drug injection.

Hepatitis C virus (HCV) is predominantly transmitted between persons who inject drugs. For this population, global prevalence of HCV infection is high and incarceration is common and an independent risk factor for HCV acquisition. To explore HCV transmission dynamics in incarcerated populations, we integrated virus sequences with risk behavior and spatiotemporal data and analyzed transmission clusters among prisoners in Australia. We detected 3 clusters of recent HCV transmission consisting of 4 likely in-custody transmission events involving source/recipient pairs located in the same prison at the same time. Of these 4 events, 3 were associated with drug injecting and equipment sharing. Despite a large population of prisoners with chronic HCV, recent transmission events were identified in the prison setting. This ongoing HCV transmission among high-risk prisoners argues for expansion of prevention programs to reduce HCV transmission in prisons.

HIV infection and hepatitis C virus genotype 1a are associated with phylogenetic clustering among people with recently acquired hepatitis C virus infection

The aim of this study was to identify factors associated with phylogenetic clustering among people with recently acquired hepatitis C virus (HCV) infection. Participants with available sample at time of HCV detection were selected from three studies; the Australian Trial in Acute Hepatitis C, the Hepatitis C Incidence and Transmission Study - Prison and Community. HCV RNA was extracted and Core to E2 region of HCV sequenced. Clusters were identified from maximum likelihood trees with 1000 bootstrap replicates using 90% bootstrap and 5% genetic distance threshold. Among 225 participants with available Core-E2 sequence (ATAHC, n=113; HITS-p, n=90; and HITS-c, n=22), HCV genotype prevalence was: G1a: 38% (n=86), G1b: 5% (n=12), G2a: 1% (n=2), G2b: 5% (n=11), G3a: 48% (n=109), G6a: 1% (n=2) and G6l 1% (n=3). Of participants included in phylogenetic trees, 22% of participants were in a pair/cluster (G1a-35%, 30/85, mean maximum genetic distance=0.031; G3a-11%, 12/106, mean maximum genetic distance=0.021; other genotypes-21%, 6/28, mean maximum genetic distance=0.023). Among HCV/HIV co-infected participants, 50% (18/36) were in a pair/cluster, compared to 16% (30/183) with HCV mono-infection (P=<0.001). Factors independently associated with phylogenetic clustering were HIV co-infection [vs. HCV mono-infection; adjusted odds ratio (AOR) 4.24; 95%CI 1.91, 9.39], and HCV G1a infection (vs. other HCV genotypes; AOR 3.33, 95%CI 0.14, 0.61).HCV treatment and prevention strategies, including enhanced antiviral therapy, should be optimised. The impact of targeting of HCV treatment as prevention to populations with higher phylogenetic clustering, such as those with HIV co-infection, could be explored through mathematical modelling.

More than just someone to inject drugs with: Injecting within primary injection partnerships

BACKGROUND

Studies have shown intimate injection partners engage in higher rates of syringe and injecting equipment sharing. We examined the drug use context and development of injection drug use behaviors within intimate injection partnerships.

METHODS

In-depth interviews (n=18) were conducted with both members of nine injecting partnerships in Sydney, Australia. Content analysis identified key domains related to the reasons for injecting with a primary injection partner and development of drug injection patterns.

MAIN FINDINGS

Most partnerships (n=5) were also sexual; three were blood-relatives and one a friend dyad. The main drug injected was heroin (66%) with high rates of recent sharing behaviors (88%) reported within dyads. Injecting within a primary injection partnership provided perceived protection against overdose events, helped reduce stress, increased control over when, where, and how drugs were used, and promoted the development of an injecting pattern where responsibilities could be shared. Unique to injecting within primary injection partnerships was the social connection and companionship resulted in a feeling of fulfillment while also blinding one from recognizing risky behavior.

CONCLUSIONS

Findings illuminated the tension between protection and risks within primary injection partnerships. Primary injection partnerships provide a potential platform to expand risk reduction strategies.

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

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

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.

Enhancing the detection and management of acute hepatitis C virus infection

Acute HCV infection refers to the 6-month period following infection acquisition, although this definition is somewhat arbitrary. While spontaneous clearance occurs in approximately 25%, the majority will develop chronic HCV infection with the potential for development of cirrhosis, end stage liver disease and hepatocellular carcinoma. Detection of acute HCV infection has been hampered by its asymptomatic or non-specific presentation, lack of specific diagnostic tests and the inherent difficulties in identifying and following individuals at highest risk of transmitting and acquiring HCV infection, such as people who inject drugs (PWID). However, recognition of those with acute infection may have individual and population level benefits and could represent an ideal opportunity for intervention. Despite demonstration that HCV treatment is feasible and successful in PWID, treatment uptake remains low with multiple barriers to care at an individual and systems level. Given the burden of HCV-related disease among PWID, strategies to enhance HCV assessment, treatment and prevention in this group are urgently needed. As the therapeutic landscape of chronic HCV management is revolutionised by the advent of simple, highly effective directly-acting antiviral (DAA) therapy, similar opportunities may exist in acute infection. This review will discuss issues surrounding improving the detection and management of acute HCV infection, particularly in PWID.

Incidence and prevalence of hepatitis c virus infection among persons who inject drugs in New York City: 2006-2013

BACKGROUND

Hepatitis C virus infection is a source of significant preventable morbidity and mortality among persons who inject drugs (PWID). We sought to assess trends in hepatitis C virus (HCV) infection among PWID from 2006 to 2013 in New York City (NYC).

METHODS

Annual cross-sectional surveys of PWID entering a large drug abuse treatment program were performed. Risk behavior questionnaires were administered, and HIV and HCV testing were conducted. Comparisons were made with prior prevalence and incidence estimates in 1990-1991 and 2000-2001 reflecting different periods of combined prevention and treatment efforts.

RESULTS

HCV prevalence among PWID (N: 1535) was 67% (95% CI: 66-70%) during the study period, and was not significantly different from that observed in 2000-2001. The estimated HCV incidence among new injectors (persons injecting for ≤6 years) during 2006-2013 was 19.5/100 PYO (95% CI: 17-23) and did not differ from that observed in 2000-2001 (18/100 PYO, 95% CI: 14-23/100).

CONCLUSIONS

Despite the expansion of combined prevention programming between 2000-2001 and 2006-2013, HCV prevalence remained high. Estimated HCV incidence among new injectors also remained high, and not significantly lower than in 2000-2001, indicating that expanded combined prevention efforts are needed to control the HCV epidemic among PWID in NYC.

Methamphetamine injecting is associated with phylogenetic clustering of hepatitis C virus infection among street-involved youth in Vancouver, Canada

BACKGROUND

Among prospective cohorts of people who inject drugs (PWID), phylogenetic clustering of HCV infection has been observed. However, the majority of studies have included older PWID, representing distant transmission events. The aim of this study was to investigate phylogenetic clustering of HCV infection among a cohort of street-involved youth.

METHODS

Data were derived from a prospective cohort of street-involved youth aged 14-26 recruited between 2005 and 2012 in Vancouver, Canada (At Risk Youth Study, ARYS). HCV RNA testing and sequencing (Core-E2) were performed on HCV positive participants. Phylogenetic trees were inferred using maximum likelihood methods and clusters were identified using ClusterPicker (Core-E2 without HVR1, 90% bootstrap threshold, 0.05 genetic distance threshold).

RESULTS

Among 945 individuals enrolled in ARYS, 16% (n=149, 100% recent injectors) were HCV antibody positive at baseline interview (n=86) or seroconverted during follow-up (n=63). Among HCV antibody positive participants with available samples (n=131), 75% (n=98) had detectable HCV RNA and 66% (n=65, mean age 23, 58% with recent methamphetamine injection, 31% female, 3% HIV+) had available Core-E2 sequences. Of those with Core-E2 sequence, 14% (n=9) were in a cluster (one cluster of three) or pair (two pairs), with all reporting recent methamphetamine injection. Recent methamphetamine injection was associated with membership in a cluster or pair (P=0.009).

CONCLUSION

In this study of street-involved youth with HCV infection and recent injecting, 14% demonstrated phylogenetic clustering. Phylogenetic clustering was associated with recent methamphetamine injection, suggesting that methamphetamine drug injection may play an important role in networks of HCV transmission.

The impact of blood-borne viruses on cause-specific mortality among opioid dependent people: An Australian population-based cohort study

BACKGROUND

Blood-borne viruses (BBV) are prevalent among people with opioid dependence but their association with cause-specific mortality has not been examined at the population-level.

METHODS

We formed a population-based cohort of 29,571 opioid substitution therapy (OST) registrants in New South Wales, Australia, 1993-2007. We ascertained notifications of infection and death by record linkage between the Pharmaceutical Drugs of Addiction System (OST data), registers of hepatitis C (HCV), hepatitis B (HBV) and human immunodeficiency virus (HIV) diagnoses, and the National Death Index. We used competing risks regression to quantify associations between notification for BBV infection and causes of death. BBV status, age, year, OST status, and OST episodes were modelled as time-dependent covariates; sex was a fixed covariate.

RESULTS

OST registrants notified with HCV infection were more likely to die from accidental overdose (subdistribution hazard ratio, 95% Confidence Interval: 1.7, 1.5-2.0), cancer (2.0, 1.3-3.2) and unintentional injury (1.4, 1.0-2.0). HBV notification was associated with a higher hazard of mortality due to unintentional injury (2.1, 1.1-3.9), cancer (2.8, 1.5-5.5), and liver disease (2.1, 1.0-4.3). Liver-related mortality was higher among those notified with HIV only (11, 2.5-50), HCV only (5.9, 3.2-11) and both HIV and HCV (15, 3.2-66). Registrants with an HIV notification had a higher hazard of cardiovascular-related mortality (4.0, 1.6-9.9).

CONCLUSIONS

Among OST registrants, BBVs are a direct cause of death and also a marker of behaviours that can result in unintended death. Ongoing and enhanced BBV prevention strategies and treatment, together with targeted education strategies to reduce risk, are justified.

Biomedical HIV Prevention Including Pre-exposure Prophylaxis and Opiate Agonist Therapy for Women Who Inject Drugs: State of Research and Future Directions

Women who inject drugs (WWID) are at higher risk of HIV compared with their male counterparts as a result of multiple factors, including biological, behavioral, and sociostructural factors, yet comparatively little effort has been invested in testing and delivering prevention methods that directly target this group. In this article, we discuss the need for expanded prevention interventions for WWID, focusing on 2 safe, effective, and approved, yet underutilized biomedical prevention methods: opiate agonist therapy (OAT) and oral pre-exposure prophylaxis (PrEP). Although both interventions are well researched, they have not been well examined in the context of gender. We discuss the drivers of women injectors' higher HIV risk, review the effectiveness of OAT and PrEP interventions among women, and explain why these new HIV prevention tools should be prioritized for WWID. There is substantial potential for impact of OAT and PrEP programs for WWID in the context of broader gender-responsive HIV prevention initiatives. Although awaiting efficacy data on other biomedical approaches in the HIV prevention research "pipeline," we propose that the scale-up and implementation of these proven, safe, and effective interventions are needed now.

Negotiating structural vulnerability following regulatory changes to a provincial methadone program in Vancouver, Canada: A qualitative study

While regulatory frameworks governing methadone maintenance therapy (MMT) require highly regimented treatment programs that shape treatment outcomes, little research has examined the effects of regulatory changes to these programs on those receiving treatment, and located their experiences within the wider context of social-structural inequities. In British Columbia (BC), Canada, provincial regulations governing MMT have recently been modified, including: replacing the existing methadone formulation with Methadose(®) (pre-mixed and 10 times more concentrated); prohibiting pharmacy delivery of methadone; and, prohibiting pharmacies incentives for methadone dispensation. We undertook this study to examine the impacts of these changes on a structurally vulnerable population enrolled in MMT in Vancouver, BC. Qualitative interviews were conducted with 34 people enrolled in MMT and recruited from two ongoing observational prospective cohort studies comprised of drug-using individuals in the six-month period in 2014 following these regulatory changes. Interview transcripts were analysed thematically, and by drawing on the concept of 'structural vulnerability'. Findings underscore how these regulatory changes disrupted treatment engagement, producing considerable health and social harms. The introduction of Methadose(®) precipitated increased withdrawal symptoms. The discontinuation of pharmacy delivery services led to interruptions in MMT and co-dispensed HIV medications due to constraints stemming from their structural vulnerability (e.g., poverty, homelessness). Meanwhile, the loss of pharmacy incentives limited access to material supports utilized by participants to overcome barriers to MMT, while diminishing their capacity to assert some degree of agency in negotiating dispensation arrangements with pharmacies. Collectively, these changes functioned to compromise MMT engagement and increased structural vulnerability to harm, including re-initiation of injection drug use and participation in high-risk income-generating strategies. Greater attention to the impacts of social-structural inequities on MMT engagement is needed when modifying MMT programs, especially as other jurisdictions are adopting similar changes. Comprehensive environmental supports should be provided to minimize adverse outcomes during transitional periods.

Opioid substitution therapy is associated with increased detection of hepatitis C virus infection: a 15-year observational cohort study

BACKGROUND

Strategies are needed to enhance screening of hepatitis C virus (HCV) infection among people who inject drugs to improve engagement in HCV treatment, and stem the growing burden of HCV-related morbidity and mortality.

METHODS

We linked routinely collected data on enrolment in opioid substitution therapy (OST) and HCV notifications. We calculated rates of incident HCV notifications, and compared rates in and out of OST.

RESULTS

Following adjustment for sex, age and calendar period, rates of incident HCV notification were significantly higher during periods of OST, compared to periods out of OST (adjusted incident rate ratio: 1.91; 95% confidence interval: 1.86, 1.97). This effect was seen across multiple treatment periods.

CONCLUSIONS

HCV screening in OST settings increases detection of HCV infection among people who inject drugs.

A prospective study of hepatitis C incidence in Australian prisoners

AIMS

To document the relationships between injecting drug use, imprisonment and hepatitis C virus (HCV) infection.

DESIGN

Prospective cohort study.

SETTING

Multiple prisons in New South Wales, Australia.

PARTICIPANTS

HCV seronegative prisoners with a life-time history of injecting drug use (IDU) were enrolled and followed prospectively (n = 210) by interview and HCV antibody and RNA testing 6-12-monthly for up to 4 years when in prison.

MEASUREMENTS

HCV incidence was calculated using the person-years method. Cox regression was used to identify predictors of incident infection using time-dependent covariates.

RESULTS

Almost half the cohort reported IDU during follow-up (103 subjects; 49.1%) and 65 (31%) also reported sharing of the injecting apparatus. There were 38 HCV incident cases in 269.94 person-years (py) of follow-up with an estimated incidence of 14.08 per 100 py [confidence interval (CI) = 9.96-19.32]. Incident infection was associated independently with Indigenous background, injecting daily or more and injecting heroin. Three subjects were RNA-positive and antibody-negative at the incident time-point, indicating early infection, which provided a second incidence estimate of 9.4%. Analysis of continuously incarcerated subjects (n = 114) followed over 126.73 py, identified 13 new HCV infections (10.26 per 100 py, CI = 5.46-17.54), one of which was an early infection case. Bleach-cleansing of injecting equipment and opioid substitution treatment were not associated with a significant reduction in incidence.

CONCLUSIONS

In New South Wales, Australia, imprisonment is associated with high rates of hepatitis C virus transmission. More effective harm reduction interventions are needed to control HCV in prison settings.

Assessing the feasibility of hepatitis C virus vaccine trials: results from the Hepatitis C Incidence and Transmission Study-community (HITS-c) vaccine preparedness study

Efficacy trials of preventive hepatitis C virus (HCV) vaccine candidates raise challenging scientific and ethical issues. Based on data from the first 3 years of a community-based prospective observational study - the Hepatitis C Incidence and Transmission Study-community (HITS-c) - this paper examines the feasibility of conducting trials of candidate HCV vaccines with people who inject drugs (PWID) in Sydney, Australia. Of the 166 PWID confirmed HCV antibody negative and eligible for enrolment, 156 (94%) completed baseline procedures. Retention was high, with 89% of participants retained at 48 weeks and 76% of participants completing at least 75% of study visits within 2 weeks of schedule. The rate of primary HCV infection was 7.9/100 py (95% CI 4.9, 12.7). Of the 17 incident cases, 16 completed at least one follow-up assessment and 12 (75%) had evidence of chronic viraemia with progression to chronic HCV infection estimated to be 6/100 py. Power calculations suggest a chronic HCV infection rate of at least 12/100 py (primary HCV infection rate 16/100 py) will be required for stand-alone trials of highly efficacious candidates designed to prevent chronic infection. However, elevated primary HCV infection was observed among participants not receiving opioid substitution therapy who reported heroin as the main drug injected (26.9/100 py, 95% CI 14.5, 50.0) and those who reported unstable housing (23.5/100 py, 95% CI 7.6, 72.8), daily or more frequent injecting (22.7/100 py, 95% CI 12.2, 42.2) and receptive syringe sharing (23.6/100 py, 95% CI 9.8, 56.7) in the 6 months prior to baseline. These data suggest that it is possible to recruit and retain at-risk PWID who adhere to study protocols and that modification of eligibility criteria may identify populations with sufficiently high HCV incidence. Results support the feasibility of large multi-centre HCV vaccine trials, including in the Australian setting.