Modelling the prevalence of HCV amongst people who inject drugs: an investigation into the risks associated with injecting paraphernalia sharing

Analysis and mapping of harm reduction research in the context of injectable drug use: identifying research hotspots, gaps and future directions

BACKGROUND

Harm reduction is a crucial approach in addressing the multifaceted challenges of injectable drug use. This paper presents an analysis and mapping of the existing literature on harm reduction research in the context of injectable drug use. By reviewing a comprehensive set of scholarly articles, this study identifies research hotspots, knowledge gaps, and future directions in the field. The findings provide valuable insights for researchers, policymakers, and practitioners to guide future research efforts and inform evidence-based harm reduction interventions.

METHODS

Data for the study was obtained from the Scopus database, using keywords and phrases related to harm reduction and injectable drug use. Validation methods were employed to verify the accuracy and comprehensiveness of the search strategy. Data analysis involved identifying growth patterns, key contributors, mapping frequent terms, identifying research hotspots, and identifying emerging research directions.

RESULTS

A total of 971 articles were found, with a notable increase from 2015 to 2022. The International Journal of Drug Policy (n = 172, 17.7%) and the Harm Reduction Journal (n = 104, 10.7%) were the most prolific journals, and the United States (n = 558, 57.5%) had the highest number of publications. The Johns Hopkins University (n = 80, 8.5%) was the most prolific institution. Mapping of frequent author keywords revealed the main keywords, including harm reduction, HIV, hepatitis C, and opioid overdose. The highly cited articles cover a broad time span and focus on topics like naloxone distribution, HIV and hepatitis C transmission, while recent articles concentrate on emerging issues such as the impact of the COVID-19 pandemic, fentanyl-related concerns, stigma reduction, and needle and syringe programs. Both sets of articles share a common focus on harm reduction strategies, but recent publications highlight current challenges and developments in the field.

CONCLUSIONS

This study provides insights into research landscape on harm reduction in injectable drug use. Research is concentrated in high-income countries, emphasizing the need for more research in low- and middle-income countries. Recent publications focus on emerging challenges like COVID-19 and fentanyl. Research gaps highlight the need for studies in diverse populations, social determinants, program evaluation, and implementation strategies to enhance harm reduction interventions.

Estimated Number of Injection-Involved Overdose Deaths in US States From 2000 to 2020: Secondary Analysis of Surveillance Data

BACKGROUND

In the United States, both drug overdose mortality and injection-involved drug overdose mortality have increased nationally over the past 25 years. Despite documented geographic differences in overdose mortality and substances implicated in overdose mortality trends, injection-involved overdose mortality has not been summarized at a subnational level.

OBJECTIVE

We aimed to estimate the annual number of injection-involved overdose deaths in each US state from 2000 to 2020.

METHODS

We conducted a stratified analysis that used data from drug treatment admissions (Treatment Episodes Data Set-Admissions; TEDS-A) and the National Vital Statistics System (NVSS) to estimate state-specific percentages of reported drug overdose deaths that were injection-involved from 2000 to 2020. TEDS-A collects data on the route of administration and the type of substance used upon treatment admission. We used these data to calculate the percentage of reported injections for each drug type by demographic group (race or ethnicity, sex, and age group), year, and state. Additionally, using NVSS mortality data, the annual number of overdose deaths involving selected drug types was identified by the following specific multiple-cause-of-death codes: heroin or synthetic opioids other than methadone (T40.1, T40.4), natural or semisynthetic opioids and methadone (T40.2, T40.3), cocaine (T40.5), psychostimulants with abuse potential (T43.6), sedatives (T42.3, T42.4), and others (T36-T59.0). We used the probabilities of injection with the annual number of overdose deaths, by year, primary substance, and demographic groups to estimate the number of overdose deaths that were injection-involved.

RESULTS

In 2020, there were 91,071 overdose deaths among adults recorded in the United States, and 93.1% (84,753/91,071) occurred in the 46 jurisdictions that reported data to TEDS-A. Slightly less than half (38,253/84,753, 45.1%; 95% CI 41.1%-49.8%) of those overdose deaths were estimated to be injection-involved, translating to 38,253 (95% CI 34,839-42,181) injection-involved overdose deaths in 2020. There was large variation among states in the estimated injection-involved overdose death rate (median 14.72, range 5.45-31.77 per 100,000 people). The national injection-involved overdose death rate increased by 323% (95% CI 255%-391%) from 2010 (3.78, 95% CI 3.33-4.31) to 2020 (15.97, 95% CI 14.55-17.61). States in which the estimated injection-involved overdose death rate increased faster than the national average were disproportionately concentrated in the Northeast region.

CONCLUSIONS

Although overdose mortality and injection-involved overdose mortality have increased dramatically across the country, these trends have been more pronounced in some regions. A better understanding of state-level trends in injection-involved mortality can inform the prioritization of public health strategies that aim to reduce overdose mortality and prevent downstream consequences of injection drug use.

Characterizing risk behaviour and reinfection rates for successful programs to engage core transmitters in HCV elimination (C-RESPECT)

BACKGROUND: Development of robust treatment programs among core transmitters (CT) of hepatitis C virus (HCV) are needed, including strategies to address reinfection risk. The aim of this study was to describe the effectiveness of direct-acting antiviral (DAA) treatment in CT versus non-CT populations and assess reinfection rates after successful treatment. METHODS: Characterizing Risk Behaviour and Reinfection Rates for Successful Programs to Engage Core Transmitters in HCV Elimination (C-RESPECT) was a prospective, observational study of HCV-infected Canadian adult patients (genotypes 1, 3, and 4) treated with DAAs between 2017 and 2020. RESULTS: The full analysis set included 429 participants (259 CT, 170 non-CT). Key differences were observed in baseline profiles: CT participants were younger (mean 42.3 [SD 11.2] y versus 55.0 [SD 11.1] y, respectively) and reported higher rates of social assistance (35.7% versus 14.8%), smoking (83.7% versus 52.4%), low socioeconomic status (yearly income <$15,000: 69.6% versus 43.9%), illicit drug use (83.7% versus 34.3%), and previous incarcerations (62.7% versus 36.9%). DAA treatment adherence was similar; 93 .5% versus 98.3% of CT versus non-CT participants completed the assigned treatment duration. Cure rates (sustained virologic response) were comparable, ranging from 94.9% to 98.1%. All reinfections were among CT participants, with a rate of 13.8/100 person-years (95% CI 9.2–20.8) with mean time to reinfection of 24.6 (SD 0.6) months; CONCLUSIONS: CT and non-CT participants respond equally well to DAA treatment; however, with some reinfections among CT participants. Innovative multidisciplinary programs must be developed to mitigate this risk in this key population.

Co-infections as Modulators of Disease Outcome: Minor Players or Major Players?

Human host and pathogen interaction is dynamic in nature and often modulated by co-pathogens with a functional role in delineating the physiological outcome of infection. Co-infection may present either as a pre-existing pathogen which is accentuated by the introduction of a new pathogen or may appear in the form of new infection acquired secondarily due to a compromised immune system. Using diverse examples of co-infecting pathogens such as Human Immunodeficiency Virus, Mycobacterium tuberculosis and Hepatitis C Virus, we have highlighted the role of co-infections in modulating disease severity and clinical outcome. This interaction happens at multiple hierarchies, which are inclusive of stress and immunological responses and together modulate the disease severity. Already published literature provides much evidence in favor of the occurrence of co-infections during SARS-CoV-2 infection, which eventually impacts the Coronavirus disease-19 outcome. The availability of biological models like 3D organoids, mice, cell lines and mathematical models provide us with an opportunity to understand the role and mechanism of specific co-infections. Exploration of multi-omics-based interactions across co-infecting pathogens may provide deeper insights into their role in disease modulation.

The Geography of Opioid Use Disorder: A Data Triangulation Approach

Opioid use disorder is complex and not easily quantified among US populations because there are no dedicated reporting systems in place. We review indicators of opioid use disorder available at the state and county (human immunodeficiency virus diagnoses among people who inject drugs, hepatitis C diagnosis in people <50 years, opioid overdose death rates, and opioid prescription rate). The interpretation of the ecological results and the visualization of indicators at the local level will provide actionable insights for clinicians and public health officials seeking to mitigate the consequences of opioid use disorder at the patient and community levels.

New hepatitis C diagnoses in Ontario, Canada are associated with the local prescription patterns of a controlled-release opioid

Increases in acute hepatitis C virus (HCV) incidence may be a result of the rising prevalence of injection drug use and the opioid epidemic. Among persons who inject drugs, sharing of needles/syringes is less common and leads to a smaller proportion of incident cases than does sharing of injection drug preparation equipment. In Canada and Europe, hydromorphone controlled release has been associated with frequent reuse and sharing of IDPE. Drug excipients within HCR have been shown to preserve virus survival within IDPE. We hypothesized that regional differences in HCV incidence would mirror regional differences in HCR prescribing. We reviewed HCV incidence data across Ontario, Canada for 2016. Opioid prescribing patterns in each Health Unit were reviewed. Multivariable Poisson regression analyses were performed to test the strength of hydromorphone controlled release dispensing patterns in explaining HCV incidence compared to all opioids. Less vehicle access, lack of education, lower income, less population density, higher white race/ethnicity and more opioid substitution therapy recipients remained significant positive predictors of hepatitis C incidence in the Ontario model. Higher hydromorphone controlled release dispensing rate was a stronger predictor of HCV incidence than all opioid prescriptions (standardized risk ratio = 1.17, P < .0001 vs sRR = 1.11, P = .02). When hydromorphone controlled release was excluded from the opioid prescription variable, dispensing patterns of all other opioids no longer remained a significant predictor (sRR = 1.042, P = .34). The observed relationship between HCV incidence and hydromorphone controlled release dispensing suggests that the type of opioid prescribed locally may contribute to variations in HCV incidence. These data add support to evidence that hydromorphone controlled release use is contributing to HCV spread in Ontario.

Prescription opioid injection among young people who inject drugs in New York City: a mixed-methods description and associations with hepatitis C virus infection and overdose

Aim

Evidence is emerging that prescription opioid (PO) injection is associated with increased health risks. This mixed-methods study compares the mechanics of PO and heroin injection and examines the demographic and drug-related correlates of lifetime PO injection in a sample of young people who inject drugs (PWID) in New York City (NYC).

Methods

Qualitative analysis of 46 semi-structured interviews with young adult opioid users ages 18–32. Interview segments describing PO injection were analyzed for common themes. Quantitative analysis of structured interviews with 539 young adult opioid users ages 18–29 recruited via respondent-driven sampling (RDS). Analyses are based on the subsample of 353 participants (65%) who reported having ever injected drugs. All variables were assessed via self-report, except hepatitis C virus status, which was established via rapid antibody testing.

Results

Participants described injecting POs and reported that preparing abuse-deterrent pills for injection is especially cumbersome, requiring extended manipulation and large amounts of water. Injecting POs, in contrast to injecting heroin, requires repeated injections per injection episode. Among RDS-recruited participants, the majority of injectors reported injecting POs, sporadically (33%) or regularly (26%), but often infrequently (≤ 7 days/month). In separate multivariable analyses controlling for syringe- and cooker-sharing, ever injecting POs was a significant predictor of testing HCV antibody-positive (AOR = 2.97) and lifetime experience of non-fatal overdose (AOR = 2.51). Ever injecting POs was independently associated with lifetime homelessness (AOR = 2.93) and having grown up in a middle-income ($51,000–100,000/year vs. ≤ $50,000/year; AOR = 1.86) or a high-income household (> $100,000/year vs. ≤ $50,000/year; AOR = 2.54).

Conclusions

Even in an urban environment like NYC with widespread heroin access, most young PWID have injected POs, although less frequently than heroin. PO injection involves practices that are known to increase risk for blood-borne viral infection (e.g., repeated injections) and predicted testing HCV-positive, as well as overdose. PO injection may also serve as a marker for a subgroup of PWID at elevated risk for multiple drug use-related comorbidities. Programs that provide prevention services to PWID need to tailor harm reduction measures and messaging to the specific practices and harms associated with the injection of POs.

Per-Contact Infectivity of Hepatitis C Virus Acquisition in Association With Receptive Needle Sharing Exposures in a Prospective Cohort of Young Adult People who Inject Drugs in San Francisco, California

Background

Sharing needles and ancillary injecting equipment is a primary risk exposure for hepatitis C virus (HCV) infection among people who inject drugs (PWID); however, infectivity of these exposures is not well quantified. We aimed to estimate per-event HCV infectivity associated with receptive needle sharing (RNS) among susceptible PWID.

Methods

Participants in a prospective cohort study of young adult PWID who were anti-HCV and HCV RNA negative at baseline and attended at least 2 follow-up study visits between 2003 and 2014 were eligible. Data were selected from the first HCV-negative through the first HCV-positive visit (or last HCV-negative among those uninfected). Anti-HCV and HCV-RNA tests were used to determine infection status. A probabilistic exposure model linking observed HCV infection outcomes to self-reported exposure events was applied to estimate infectivity.

Results

Among 344 participants, a maximum likelihood estimate considering RNS yielded a pooled population per RNS event HCV probability of 0.25% (95% confidence interval [CI], 0.10%–0.43%), and 1.12% (95% CI, 0.48%–2.35%) among those who acquired any HCV infection (primary or reinfection).

Conclusions

HCV is highly infectious in association with RNS, a primary injection-related risk exposure. Our infectivity estimate among participants who acquired any HCV infection is 1.7 times higher than that estimated for HIV infection in PWID and 2.24 times higher than that estimated among health care workers exposed through needle sticks. The strengths of this study include the assessment of receptive needle sharing events, the prospective design, and relatively short recall and testing periods. These results can inform transmission models and research to prevent HCV infection.

Heating Injection Drug Preparation Equipment Used for Opioid Injection May Reduce HIV Transmission Associated With Sharing Equipment

Supplemental Digital Content is Available in the Text.

Background:

London, Canada, experienced an HIV outbreak among persons who inject drugs despite widespread distribution of harm reduction equipment. Hydromorphone controlled-release (HMC) is the local opioid of choice. Injection drug preparation equipment (IDPE; ie, cookers and filters) is often shared and reused because of the perception that there is residual HMC in the IDPE after use. The purpose of this study was to investigate the mechanisms of HIV transmission in this context.

Methods:

Residual hydromorphone, (controlled-release or immediate-release), remaining in the IDPE, was measured with liquid chromatography–tandem mass spectrometry, in conditions replicating persons who inject drug use. HIV was added to IDPE in the presence HMC, hydromorphone immediate-release, or microcrystalline cellulose (an HMC drug excipient). HIV viral persistence was measured by reverse transcriptase activity and infectivity of indicator Tzm-bl cells.

Results:

Forty-five percent of HMC remained in the IDPE after the first aspiration of solution, with no change after heating. HIV persistence and infectivity were preserved in the presence of HMC, and less so with microcrystalline cellulose. Heating the IDPE rapidly inactivated HIV.

Conclusions:

Sharing of IDPE is a potential means of HIV transmission. HMC encourages IDPE sharing because of the residual drug in the IDPE, and the HMC excipients preserve HIV viability. Heating IDPE before aspiration of the opioid may be a harm reduction strategy.

Sharing of Injection Drug Preparation Equipment Is Associated With HIV Infection: A Cross-sectional Study

Background:

Sharing needles/syringes and sexual transmission are widely appreciated as means of HIV transmission among persons who inject drugs (PWIDs). London, Canada, is experiencing an outbreak of HIV among PWIDs, despite a large needle/syringe distribution program and low rates of needle/syringe sharing.

Objective:

To determine whether sharing of injection drug preparation equipment (IDPE) is associated with HIV infection.

Methods:

Between August 2016 and June 2017, individuals with a history of injection drug use and residence in London were recruited to complete a comprehensive questionnaire and HIV testing.

Results:

A total of 127 participants were recruited; 8 were excluded because of failure to complete HIV testing. The remaining 35 HIV-infected (cases) and 84 HIV-uninfected (controls) participants were assessed. Regression analysis found that sharing IDPE, without sharing needles/syringes, was strongly associated with HIV infection (adjusted odds ratio: 22.1, 95% confidence interval: 4.51 to 108.6, P < 0.001).

Conclusions:

Sharing of IDPE is a risk factor for HIV infection among PWIDs, even in the absence of needle/syringe sharing. Harm reduction interventions to reduce HIV transmission associated with this practice are urgently needed.

Hepatitis C elimination - Macro-elimination

In 2016 the WHO set a goal to obtain an 80% reduction in new chronic HCV cases, requiring a level of diagnosis of 90%, treatment coverage of 80% and resulting in a 65% reduction in HCV-related deaths by 2030. This goal is easier to reach in specific populations such as people who inject drugs (PWID), men who have sex with men (MSM) or blood-transfusion recipients before screening for HCV became mandatory and in high-income regions. It is much more difficult to achieve macro-elimination throughout the population especially in low-income areas with underdeveloped infrastructures, a high prevalence of HCV and limited economic resources. To achieve the WHO goals by 2030, awareness of HCV must increase and the cascade of care must be improved and implemented. Diagnostic procedures and treatment should be affordable and universally available. At the end of 2017 fewer than 15 countries were on track to reach these goals by 2030.

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

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

HIV- and hepatitis C-related risk behaviors among people who inject drugs in Uganda: implications for policy and programming

BACKGROUND

There is a dearth of evidence on injecting drug use and associated HIV and hepatitis C virus (HCV) infections in Uganda. As such, policy and programming for people who inject drugs (PWID) is limited due to scarcity of epidemiological data. We therefore conducted this study to assess the injecting drug and sexual practices among PWID in Kampala Capital City and Mbale Municipality.

METHODS

Using a rapid situation assessment framework, we conducted semi-structured interviews among 125 PWID (102 males and 23 females)-recruited through outreach and snowball sampling. We assessed their injecting drug and sexual practices. We also conducted 12 focus group discussions among PWID and 30 in-depth interviews among key informants.

RESULTS

A total of 125 PWID (81.6% males and 18.4% females) were recruited into the study. Approximately three quarters of PWID started injecting before the age of 25. More females (21.7%) compared to males (13.7%) started injecting by the age of 17. Fifty-seven percent of the PWID in Kampala and 50% in Mbale shared injecting equipment in the last 3 months prior to the study. There was an emerging practice of mixing drugs with blood and sharing it among different PWID as a sign of oneness. Heroin was being injected by 72% of the participants. Less than one half of the PWID had used a condom during the last casual sex, and 42.7% did not use a condom the last time they engaged in sex work. Seventy-six percent of the PWID had undertaken an HIV test in the last 12 months, and 9.2% self-reported to be HIV positive.

CONCLUSIONS

This study highlights the need for introducing harm reduction policies and services including increased access to sterile injecting equipment and education around safer injecting and sexual practices. Programs for PWID should also address the specific needs of female sex workers who inject drugs.

Usage of low dead space syringes and association with hepatitis C prevalence amongst people who inject drugs in the UK

INTRODUCTION

Syringes with attached needles (low dead space syringes [LDSS]) retain far less blood following injection than syringes with detachable needles (high dead space syringes [HDSS]). People who inject drugs (PWID) who share needles/syringes may be less likely to acquire Hepatitis C virus (HCV) infection using LDSS, compared with HDSS, but data are limited.

METHODS

Utilizing drug behavior and HCV antibody testing data from the UK 2014/2015 Unlinked Anonymous Monitoring Survey of PWID, we calculated the percentage of syringes used in the past month that were LDSS. We investigated which injecting characteristics and demographic factors were associated with 100% LDSS (against 0-99%) usage, and whether 100% LDSS use was associated with antibody HCV-status, after adjusting for confounders.

RESULT

Of 2174 participants, 55% always used LDSS, 27% always used HDSS, and 17% used both LDSS and HDSS. PWID that had injected into their groin during the past month were unlikely to use LDSS, adjusted odds ratio (aOR) 0.14 (95% confidence interval 0.11-0.17), compared to those not using the groin. Those injecting crack were less likely to use LDSS than those not, aOR 0.79 (0.63-0.98). Polydrug use was negatively associated with LDSS use, aOR 0.88 (0.79-0.98) per additional drug. LDSS use was associated with lower prevalent HCV among all PWID (aOR 0.77, [0.64-0.93]), which was stronger among recent initiates (aOR 0.53 [0.30-0.94]) than among experienced PWID (aOR 0.81 [0.66-0.99]).

DISCUSSION

People who inject into their groin were less likely to use LDSS. Exclusive LDSS use was associated with lower prevalence of HCV amongst PWID that started injecting recently, suggesting LDSS use is protective against HCV.

Virological and Immunological Outcomes of Coinfections

Coinfections involving viruses are being recognized to influence the disease pattern that occurs relative to that with single infection. Classically, we usually think of a clinical syndrome as the consequence of infection by a single virus that is isolated from clinical specimens. However, this biased laboratory approach omits detection of additional agents that could be contributing to the clinical outcome, including novel agents not usually considered pathogens. The presence of an additional agent may also interfere with the targeted isolation of a known virus. Viral interference, a phenomenon where one virus competitively suppresses replication of other coinfecting viruses, is the most common outcome of viral coinfections. In addition, coinfections can modulate virus virulence and cell death, thereby altering disease severity and epidemiology. Immunity to primary virus infection can also modulate immune responses to subsequent secondary infections. In this review, various virological mechanisms that determine viral persistence/exclusion during coinfections are discussed, and insights into the isolation/detection of multiple viruses are provided. We also discuss features of heterologous infections that impact the pattern of immune responsiveness that develops.

HIV incidence among people who inject drugs in the Middle East and North Africa: mathematical modelling analysis

INTRODUCTION

Emerging HIV epidemics have been documented among people who inject drugs (PWID) in the Middle East and North Africa (MENA). This study estimates the HIV incidence among PWID due to sharing needles/syringes in MENA. It also delineates injecting drug use role as a driver of the epidemic in the population, and estimates impact of interventions.

METHODS

A mathematical model of HIV transmission among PWID was applied in seven MENA countries with sufficient and recent epidemiological data and HIV prevalence ≥1% among PWID. Estimations of incident and/or prevalent infections among PWID, ex-PWID and sexual partners of infected current and ex-PWID were conducted.

RESULTS

The estimated HIV incidence rate for 2017 among PWID ranged between 0.7% per person-year (ppy) in Tunisia and 7.8% ppy in Pakistan, with Libya being an outlier (24.8% ppy). The estimated number of annual new infections was lowest in Tunisia (n = 79) and Morocco (n = 99), and highest in Iran and Pakistan (approximately n = 6700 each). In addition, 20 to 2208 and 5 to 837 new annual infections were estimated across the different countries among sexual partners of PWID and ex-PWID respectively. Since epidemic emergence, the number of total ever acquired incident infections across countries was 706 to 90,015 among PWID, 99 to 18,244 among sexual partners of PWID, and 16 to 4360 among sexual partners of ex-PWID. The estimated number of prevalent infections across countries was 341 to 23,279 among PWID, 119 to 16,540 among ex-PWID, 67 to 10,752 among sexual partners of PWID, and 12 to 2863 among sexual partners of ex-PWID. Increasing antiretroviral therapy (ART) coverage to the global target of 81% - factoring in ART adherence and current coverage - would avert about half of new infections among PWID and their sexual partners. Combining ART with harm reduction could avert over 90% and 70% of new infections among PWID and their sexual partners respectively.

CONCLUSIONS

There is considerable HIV incidence among PWID in MENA. Of all new infections ultimately due to injecting drug use, about 75% are among PWID and the rest among sexual partners. Of all prevalent infections ultimately attributed to injecting drug use as epidemic driver, about half are among PWID, 30% among ex-PWID and 20% among sexual partners of PWID and ex-PWID. These findings call for scale-up of services for PWID, including harm reduction as well as testing and treatment services.

Preventing blood-borne virus infection in people who inject drugs in the UK: systematic review, stakeholder interviews, psychosocial intervention development and feasibility randomised controlled trial

BACKGROUND

Opioid substitution therapy and needle exchanges have reduced blood-borne viruses (BBVs) among people who inject drugs (PWID). Some PWID continue to share injecting equipment.

OBJECTIVES

To develop an evidence-based psychosocial intervention to reduce BBV risk behaviours and increase transmission knowledge among PWID, and conduct a feasibility trial among PWID comparing the intervention with a control.

DESIGN

A pragmatic, two-armed randomised controlled, open feasibility trial. Service users were Steering Group members and co-developed the intervention. Peer educators co-delivered the intervention in London.

SETTING

NHS or third-sector drug treatment or needle exchanges in Glasgow, London, Wrexham and York, recruiting January and February 2016.

PARTICIPANTS

Current PWID, aged ≥ 18 years.

INTERVENTIONS

A remote, web-based computer randomisation system allocated participants to a three-session, manualised, psychosocial, gender-specific group intervention delivered by trained facilitators and BBV transmission information booklet plus treatment as usual (TAU) (intervention), or information booklet plus TAU (control).

MAIN OUTCOME MEASURES

Recruitment, retention and follow-up rates measured feasibility. Feedback questionnaires, focus groups with participants who attended at least one intervention session and facilitators assessed the intervention's acceptability.

RESULTS

A systematic review of what works to reduce BBV risk behaviours among PWID; in-depth interviews with PWID; and stakeholder and expert consultation informed the intervention. Sessions covered improving injecting technique and good vein care; planning for risky situations; and understanding BBV transmission. Fifty-six per cent (99/176) of eligible PWID were randomised: 52 to the intervention group and 47 to the control group. Only 24% (8/34) of male and 11% (2/18) of female participants attended all three intervention sessions. Overall, 50% (17/34) of men and 33% (6/18) of women randomised to the intervention group and 47% (14/30) of men and 53% (9/17) of women randomised to the control group were followed up 1 month post intervention. Variations were reported by location. The intervention was acceptable to both participants and facilitators. At 1 month post intervention, no increase in injecting in 'risky' sites (e.g. groin, neck) was reported by participants who attended at least one session. PWID who attended at least one session showed a trend towards greater reduction in injecting risk behaviours, a greater increase in withdrawal planning and were more confident about finding a vein. A mean cost of £58.17 per participant was calculated for those attending one session, £148.54 for those attending two sessions and £270.67 for those attending all three sessions, compared with £0.86 in the control group. Treatment costs across the centres vary as a result of the different levels of attendance, as total session costs are divided by attendees to obtain a cost per attendee. The economic analysis suggests that a cost-effectiveness study would be feasible given the response rates and completeness of data. However, we have identified aspects where the service use questionnaire could be abbreviated given the low numbers reported in several care domains. No adverse events were reported.

CONCLUSIONS

As only 19% of participants attended all three intervention sessions and 47% were followed up 1 month post intervention, a future definitive randomised controlled trial of the intervention is not feasible. Exposure to information on improving injecting techniques did not encourage riskier injecting practices or injecting frequency, and benefits were reported among attendees. The intervention has the potential to positively influence BBV prevention. Harm reduction services should ensure that the intervention content is routinely delivered to PWID to improve vein care and prevent BBVs.

FUTURE WORK

The intervention did not meet the complex needs of some PWID, more tailoring may be needed to reach PWID who are more frequent injectors, who are homeless and female.

LIMITATIONS

Intervention delivery proved more feasible in London than other locations. Non-attendance at the York trial site substantially influenced the results.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN66453696 and PROSPERO 014:CRD42014012969.

FUNDING

This project was funded by the National Institute for Health Research Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 72. See the NIHR Journals Library website for further project information.

Prevalence of hepatitis C and pre-testing awareness of hepatitis C status in 1500 consecutive PWID participants at the Stockholm needle exchange program

BACKGROUND

People who inject drugs (PWID) are the driving force of the hepatitis C virus (HCV) epidemic. Still, treatment is scarcely offered and the awareness of HCV status in PWID is poor. Prevention includes clean needles, syringes and other paraphernalia. HCV awareness was investigated in 1500 PWID in a needle exchange program (NEP) in Stockholm, Sweden, together with HCV prevalence, and time to HCV infection after start of injection drug use.

METHODS

1500 PWID in the Stockholm NEP were consecutively enrolled. At baseline, awareness of the individual pre-test HCV status was measured followed with tests for anti-HCV and HCV RNA if anti-HCV was positive.

RESULTS

Mean age of participants was 39 years and the mean time of injection drug use 18 (0-51) years. The overall anti-HCV prevalence was 82% whereof 76% were HCV RNA positive. Within 4 years after start of injection drug use 50% of the participants were anti-HCV positive. Self-awareness of HCV status was low. Hence, 32% who believed that they never have encountered HCV were anti-HCV positive, and 24% were HCV RNA positive. For those who reported not being aware of their HCV status 62% were anti-HCV positive, and 47% were HCV RNA positive.

CONCLUSION

The very high prevalence of chronic HCV in PWID in Stockholm indicates that both measures for prevention with increased awareness of HCV, and a higher antiviral treatment utilisation in combination need to be implemented in order to reduce the HCV prevalence and combat the HCV epidemic.

Hepatitis C infection and other drug-related harms among inpatients who injected drugs in Turkey

Hepatitis C virus (HCV) is easily spread among those who share drug injection equipment. Due to the ease of contraction and growing prevalence of HCV in Eastern Europe, the aims of this study focused on describing risky injection practices as well as the prevalence of HCV, HIV and hepatitis B virus (HBV) among people who inject drugs (PWID) who were admitted to public and private drug treatment centres in Turkey from 2012 to 2013. Other aims included identifying correlates of needle sharing and HCV infection. Of the 4694 inpatients who ever injected drugs and the 3914 who injected in the past 30 days, nearly all (98%) reported heroin as their drug of choice, the vast majority reported ever sharing a needle (73.4% and 79.3%), and the mean age at first injection was 23 years. Of current PWID, 51.9% were HCV-positive, 5.9% were HBV-positive and only 0.34% of lifetime PWID were HIV-positive. Predictors of increased needle sharing include younger age, being unemployed, having lesser education and reporting heroin as a drug of choice. Significant predictors of HCV infection included being 40 years or older, receiving treatment in the Mediterranean region of Turkey, reporting heroin as a primary substance, a longer duration of drug use and sharing needles. With this information, it is essential to improve access to clean injection equipment in Turkey, to focus on improving education on clean injection practices and to enhance efforts in testing and treating HCV-positive PWID.

The acceptability and feasibility of a brief psychosocial intervention to reduce blood-borne virus risk behaviours among people who inject drugs: a randomised control feasibility trial of a psychosocial intervention (the PROTECT study) versus treatment as usual

BACKGROUND

While opiate substitution therapy and injecting equipment provision (IEP) have reduced blood-borne viruses (BBV) among people who inject drugs (PWID), some PWID continue to share injecting equipment and acquire BBV. Psychosocial interventions that address risk behaviours could reduce BBV transmission among PWID.

METHODS

A pragmatic, two-armed randomised controlled, open feasibility study of PWID attending drug treatment or IEP in four UK regions. Ninety-nine PWID were randomly allocated to receive a three-session manualised psychosocial group intervention and BBV transmission information booklet plus treatment as usual (TAU) (n = 52) or information booklet plus TAU (n = 47). The intervention was developed from evidence-based literature, qualitative interviews with PWID, key stakeholder consultations, and expert opinion. Recruitment rates, retention in treatment, follow-up completion rates and health economic data completion measured feasibility.

RESULTS

Fifty-six percent (99/176) of eligible PWID were recruited. More participants attended at least one intervention session in London (10/16; 63%) and North Wales (7/13; 54%) than in Glasgow (3/12; 25%) and York (0/11). Participants who attended no sessions (n = 32) compared to those attending at least one (n = 20) session were more likely to be homeless (56 vs 25%, p = 0.044), injected drugs for a greater number of days (median 25 vs 6.5, p = 0.019) and used a greater number of needles from an IEP in the last month (median 31 vs 20, p = 0.056). No adverse events were reported. 45.5% (45/99) were followed up 1 month post-intervention. Feedback forms confirmed that the intervention was acceptable to both intervention facilitators and participants who attended it. Follow-up attendance was associated with fewer days of injecting in the last month (median 14 vs 27, p = 0.030) and fewer injections of cocaine (13 vs 30%, p = 0.063). Analysis of the questionnaires identified several service use questionnaire categories that could be excluded from the assessment battery in a full-randomised controlled trial.

CONCLUSIONS

Findings should be interpreted with caution due to small sample sizes. A future definitive RCT of the psychosocial intervention is not feasible. The complex needs of some PWID may have limited their engagement in the intervention. More flexible delivery methods may have greater reach.

TRIAL REGISTRATION

ISRCTN66453696.

HCV epidemiology in high-risk groups and the risk of reinfection

Injecting risk behaviours among people who inject drugs (PWID) and high-risk sexual practices among men who have sex with men (MSM) are important routes of hepatitis C virus (HCV) transmission. Current direct-acting antiviral treatment offers unique opportunities for reductions in HCV-related liver disease burden and epidemic control in high-risk groups, but these prospects could be counteracted by HCV reinfection due to on-going risk behaviours after successful treatment. Based on existing data from small and heterogeneous studies of interferon-based treatment, the incidence of reinfection after sustained virological response range from 2-6/100 person years among PWID to 10-15/100 person years among human immunodeficiency virus-infected MSM. These differences mainly reflect heterogeneity in study populations with regards to risk behaviours, but also reflect variations in study designs and applied virological methods. Increasing levels of reinfection are to be expected as we enter the interferon-free treatment era. Individual- and population-level efforts to address and prevent reinfection should therefore be undertaken when providing HCV care for people with on-going risk behaviour. Constructive strategies include acknowledgement, education and counselling, harm reduction optimization, scaled-up treatment including treatment of injecting networks, post-treatment screening, and rapid retreatment of reinfections.

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

BACKGROUND

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

AIM

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

METHODS

Expert review of the literature.

RESULTS

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

CONCLUSIONS

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

Potential cost-effectiveness of supervised injection facilities in Toronto and Ottawa, Canada

BACKGROUND AND AIMS

Supervised injection facilities (legally sanctioned spaces for supervised consumption of illicitly obtained drugs) are controversial public health interventions. We determined the optimal number of facilities in two Canadian cities using health economic methods.

DESIGN

Dynamic compartmental model of HIV and hepatitis C transmission through sexual contact and sharing of drug use equipment.

SETTING

Toronto and Ottawa, Canada.

PARTICIPANTS

Simulated population of each city.

INTERVENTIONS

Zero to five supervised injection facilities.

MEASUREMENTS

Direct health-care costs and quality-adjusted life-years (QALYs) over 20 years, discounted at 5% per year; incremental cost-effectiveness ratios.

FINDINGS

In Toronto, one facility cost $4.1 million and resulted in a gain of 385 QALYs over 20 years, for an incremental cost-effectiveness ratio (ICER) of $10,763 per QALY [95% credible interval (95CrI): cost-saving to $278,311]. Establishing one facility in Ottawa had an ICER of $6127 per QALY (95CrI: cost-saving to $179,272). At a $50,000 per QALY threshold, three facilities would be cost-effective in Toronto and two in Ottawa. The probability that establishing three, four, or five facilities in Toronto was cost-effective was 17, 21, and 41%, respectively. Establishing one, two, or three facilities in Ottawa was cost-effective with 13, 35, and 41% probability, respectively. Establishing no facility was unlikely to be the most cost-effective option (14% in Toronto and 10% in Ottawa). In both cities, results were robust if the reduction in needle-sharing among clients of the facilities was at least 50% and fixed operating costs were less than $2.0 million.

CONCLUSIONS

Using a $50,000 per quality-adjusted life-years threshold for cost-effectiveness, it is likely to be cost-effective to establish at least three legally sanctioned spaces for supervised injection of illicitly obtained drugs in Toronto, Canada and two in Ottawa, Canada.

Modelling the prevalence of hepatitis C virus amongst blood donors in Libya: An investigation of providing a preventive strategy

AIM: To determine hepatitis C virus (HCV) seroprevalence among the Libyan population using blood donors and applying the autoregressive integrated moving average (ARIMA) model to predict future trends and formulate plans to minimize the burden of HCV infection.

METHODS: HCV positive cases were collected from 1008214 healthy blood donors over a 6-year period from 2008 to 2013. Data were used to construct the ARIMA model to forecast HCV seroprevalence among blood donors. The validity of the model was assessed using the mean absolute percentage error between the observed and fitted seroprevalence. The fitted ARIMA model was used to forecast the incidence of HCV beyond the observed period for the year 2014 and further to 2055.

RESULTS: The overall prevalence of HCV among blood donors was 1.8%, varying over the study period from 1.7% to 2.5%, though no significant variation was found within each calendar year. The ARIMA model showed a non-significant auto-correlation of the residuals, and the prevalence was steady within the last 3 years as expressed by the goodness-of-fit test. The forecast incidence showed an increase in HCV seropositivity in 2014, ranging from 500 to 700 per 10000 population, with an overall prevalence of 2.3%-2.7%. This may be extended to 2055 with minimal periodical variation within each 6-year period.

CONCLUSION: The applied model was found to be valuable in evaluating the seroprevalence of HCV among blood donors, and highlighted the growing burden of such infection on the Libyan health care system. The model may help in formulating national policies to prevent increases in HCV infection and plan future strategies that target the consequences of the infection.

Dynamic modelling of hepatitis C virus transmission among people who inject drugs: a methodological review

Equipment sharing among people who inject drugs (PWID) is a key risk factor in infection by hepatitis C virus (HCV). Both the effectiveness and cost-effectiveness of interventions aimed at reducing HCV transmission in this population (such as opioid substitution therapy, needle exchange programmes or improved treatment) are difficult to evaluate using field surveys. Ethical issues and complicated access to the PWID population make it difficult to gather epidemiological data. In this context, mathematical modelling of HCV transmission is a useful alternative for comparing the cost and effectiveness of various interventions. Several models have been developed in the past few years. They are often based on strong hypotheses concerning the population structure. This review presents compartmental and individual-based models to underline their strengths and limits in the context of HCV infection among PWID. The final section discusses the main results of the papers.

Emerging Risks Due to New Injecting Patterns in Hungary During Austerity Times

As a consequence of the massive restructuring of drug availability, heroin injection in Hungary was largely replaced by the injecting of new psychoactive substances (NPS) starting in 2010. In the following years in our sero-prevalence studies we documented higher levels of injecting paraphernalia sharing, daily injection-times, syringe reuse, and HCV prevalence among stimulant injectors, especially among NPS injectors. Despite the increasing demand, in 2012 the number of syringes distributed dropped by 35% due to austerity measures. Effects of drug market changes and the economic recession may have future epidemiological consequences. Study limitations are noted and future needed research is suggested.

A coinfection model for HIV and HCV

We study a mathematical model for the human immunodeficiency virus (HIV) and hepatites C virus (HCV) coinfection. The model predicts four distinct equilibria: the disease free, the HIV endemic, the HCV endemic, and the full endemic equilibria. The local and global stability of the disease free equilibrium was calculated for the full model and the HIV and HCV submodels. We present numerical simulations of the full model where the distinct equilibria can be observed. We show simulations of the qualitative changes of the dynamical behavior of the full model for variation of relevant parameters. From the results of the model, we infer possible measures that could be implemented in order to reduce the number of infected individuals.

Per-event probability of hepatitis C infection during sharing of injecting equipment

Background

Shared injecting apparatus during drug use is the premier risk factor for hepatitis C virus (HCV) transmission.

Aims

To estimate the per-event probability of HCV infection during a sharing event, and the transmission probability of HCV from contaminated injecting apparatus.

Methods

Estimates were obtained using a maximum likelihood method with estimated IDU and sharing events obtained from behavioural data.

Settings

Cohort study in multiple correction centres in New South Wales, Australia

Participants

Subjects (N = 500) with a lifetime history of injecting drug use (IDU) who were followed up between 2005 and 2012. During follow-up, interviews for risk behaviours were taken and blood sampling (HCV-antibody and RNA testing) was performed.

Measurements

Self-reported frequencies of injecting drugs and sharing events, as well as other risk behaviours and details on the nature of injecting events.

Findings

The best estimate of the per-event probability of infection was 0.57% (CI: 0.32–1.05%). A sensitivity analysis on the likely effect of under-reporting of sharing of the injecting apparatus indicated that the per event infection probability may be as low as 0.17% (95% CI: 0.11%–0.25%). The transmission probability was similarly shown to range up to 6%, dependent on the presumed prevalence of the virus in injecting equipment.

Conclusions

The transmission probability of HCV during a sharing event is small. Hence, strategies to reduce the frequency and sharing of injecting equipment are required, as well as interventions focused on decreasing the per event risk.