Needle Exchange and Injection-Related Risk Behaviors in Chicago

Syringe reuse among people who inject drugs in rural Appalachian Kentucky

BACKGROUND

Personal syringe reuse (i.e., reuse of one's own syringes) can place people who inject drugs at increased risk for infectious disease but has received relatively little attention in published literature. The purpose of this study is to identify factors associated with syringe reuse among people who inject drugs in rural Kentucky.

METHODS

Participants (n = 238) completed interviewer-administered questionnaires on syringe reuse and demographic, behavioral, and service access characteristics. Unadjusted negative binomial regression with cluster-robust standard errors was used to model the associations with a logged offset for number of injections in the past 30 days.

RESULTS

The average age of the sample was 35 and 59.7 % were male. Most participants (77.7 %) reused syringes at least once in the past 30 days, using each syringe a median of three times. Reuse was higher among those who were older and reported a higher street price for syringes. Syringe reuse was lower among people who were within walking distance to a syringe service program (SSP) and who obtained most of their syringes from SSPs or pharmacies.

CONCLUSION

Syringe reuse among people who inject drugs in rural Kentucky is common. However, these data suggest that increased access to syringes from SSPs and pharmacies, as well as policy-level interventions that reduce street syringe price, might reduce syringe reuse and related harms.

Project CHARIOT: study protocol for a hybrid type 1 effectiveness-implementation study of comprehensive tele-harm reduction for engagement of people who inject drugs in HIV prevention services

BACKGROUND

People who inject drugs (PWID) remain a high priority population under the federal Ending the HIV Epidemic initiative with 11% of new HIV infections attributable to injection drug use. There is a critical need for innovative, efficacious, scalable, and community-driven models of healthcare in non-stigmatizing settings for PWID. We seek to test a Comprehensive-TeleHarm Reduction (C-THR) intervention for HIV prevention services delivered via a syringe services program (SSP).

METHODS

The CHARIOT trial is a hybrid type I effectiveness-implementation study using a parallel two-arm randomized controlled trial design. Participants (i.e., PWID; n = 350) will be recruited from a syringe services program (SSP) in Miami, Florida. Participants will be randomized to receive either C-THR or non-SSP clinic referral and patient navigation. The objectives are: (1) to determine if the C-THR intervention increases engagement in HIV prevention (i.e., HIV pre-exposure prophylaxis; PrEP or medications for opioid use disorder; MOUD) compared to non-SSP clinic referral and patient navigation, (2) to examine the long-term effectiveness and cost-effectiveness of the C-THR intervention, and (3) to assess the barriers and facilitators to implementation and sustainment of the C-THR intervention. The co-primary outcomes are PrEP or MOUD engagement across follow-up at 3, 6, 9 and 12 months. For PrEP, engagement is confirmed by tenofovir on dried blood spot or cabotegravir injection within the previous 8 weeks. For MOUD, engagement is defined as screening positive for norbuprenorphine or methadone on urine drug screen; or naltrexone or buprenorphine injection within the previous 4 weeks. Secondary outcomes include PrEP adherence, engagement in HCV treatment and sustained virologic response, and treatment of sexually transmitted infections. The short and long term cost-effectiveness analyses and mixed-methods implementation evaluation will provide compelling data on the sustainability and possible impact of C-THR on comprehensive HIV prevention delivered via SSPs.

DISCUSSION

The CHARIOT trial will be the first to our knowledge to test the efficacy of an innovative, peer-led telehealth intervention with PWID at risk for HIV delivered via an SSP. This innovative healthcare model seeks to transform the way PWID access care by bypassing the traditional healthcare system, reducing multi-level barriers to care, and meeting PWID where they are.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05897099. Trial registry name: Comprehensive HIV and Harm Prevention Via Telehealth (CHARIOT). Registration date: 06/12/2023.

Spatial inequities in access to medications for treatment of opioid use disorder highlight scarcity of methadone providers under counterfactual scenarios

Access to treatment and medication for opioid use disorder (MOUD) is essential in reducing opioid use and associated behavioral risks, such as syringe sharing among persons who inject drugs (PWID). Syringe sharing among PWID carries high risk of transmission of serious infections such as hepatitis C and HIV. MOUD resources, such as methadone provider clinics, however, are often unavailable to PWID due to barriers like long travel distance to the nearest methadone provider and the required frequency of clinic visits. The goal of this study is to examine the uncertainty in the effects of travel distance in initiating and continuing methadone treatment and how these interact with different spatial distributions of methadone providers to impact co-injection (syringe sharing) risks. A baseline scenario of spatial access was established using the existing locations of methadone providers in a geographical area of metropolitan Chicago, Illinois, USA. Next, different counterfactual scenarios redistributed the locations of methadone providers in this geographic area according to the densities of both the general adult population and according to the PWID population per zip code. We define different reasonable methadone access assumptions as the combinations of short, medium, and long travel distance preferences combined with three urban/suburban travel distance preference. Our modeling results show that when there is a low travel distance preference for accessing methadone providers, distributing providers near areas that have the greatest need (defined by density of PWID) is best at reducing syringe sharing behaviors. However, this strategy also decreases access across suburban locales, posing even greater difficulty in regions with fewer transit options and providers. As such, without an adequate number of providers to give equitable coverage across the region, spatial distribution cannot be optimized to provide equitable access to all PWID. Our study has important implications for increasing interest in methadone as a resurgent treatment for MOUD in the United States and for guiding policy toward improving access to MOUD among PWID.

Modeling hepatitis C micro-elimination among people who inject drugs with direct-acting antivirals in metropolitan Chicago

Hepatitis C virus (HCV) infection is a leading cause of chronic liver disease and mortality worldwide. Direct-acting antiviral (DAA) therapy leads to high cure rates. However, persons who inject drugs (PWID) are at risk for reinfection after cure and may require multiple DAA treatments to reach the World Health Organization's (WHO) goal of HCV elimination by 2030. Using an agent-based model (ABM) that accounts for the complex interplay of demographic factors, risk behaviors, social networks, and geographic location for HCV transmission among PWID, we examined the combination(s) of DAA enrollment (2.5%, 5%, 7.5%, 10%), adherence (60%, 70%, 80%, 90%) and frequency of DAA treatment courses needed to achieve the WHO's goal of reducing incident chronic infections by 90% by 2030 among a large population of PWID from Chicago, IL and surrounding suburbs. We also estimated the economic DAA costs associated with each scenario. Our results indicate that a DAA treatment rate of >7.5% per year with 90% adherence results in 75% of enrolled PWID requiring only a single DAA course; however 19% would require 2 courses, 5%, 3 courses and <2%, 4 courses, with an overall DAA cost of $325 million to achieve the WHO goal in metropolitan Chicago. We estimate a 28% increase in the overall DAA cost under low adherence (70%) compared to high adherence (90%). Our modeling results have important public health implications for HCV elimination among U.S. PWID. Using a range of feasible treatment enrollment and adherence rates, we report robust findings supporting the need to address re-exposure and reinfection among PWID to reduce HCV incidence.

Reduction in injection risk behaviors after implementation of a syringe services program, Miami, Florida

INTRODUCTION

Syringe services programs (SSPs) are evidence-based HIV prevention programs for people who inject drugs. However, not all SSPs operate evidence-based syringe distribution models, such as needs-based distribution. This study aims to provide preliminary evidence from the IDEA SSP on changes in injection risk behaviors over time, and to examine factors, including syringe coverage, associated with injection risk behavior trajectories over time under a one-for-one syringe distribution model.

METHODS

We used a prospective observational study design to generate a cohort of SSP clients who completed three behavioral assessments at SSP service visits between December 2016 and January 2020 (N = 115). The study used generalized estimating equations (GEE) to examine the relationship between covariate measures and the primary outcomes. The primary outcomes were 1) sharing of any injection equipment (e.g. syringes, needles, cookers, cottons) in the previous 30 days (yes/no) and 2) reusing of needles/syringes in the previous 30 days (yes/no).

RESULTS

Men were more likely to report reusing syringes (aRR = 1.15, 95% CI: 1.01-1.37) and those who reported injecting in public were less likely to report reusing syringes (aRR = 0.90, 95% CI: 0.82-0.99). HCV-positive clients had a 62% reduction in sharing injection equipment and those who reported public injection had a 62% increase in sharing injection equipment over time. Most importantly, increasing syringe coverage was associated with a decrease in both sharing injection equipment (aRR = 0.42, 95% CI: 0.25-0.72) and reusing syringes (aRR = 0.79, 95% CI: 0.66-0.95).

CONCLUSION

This study provides preliminary evidence of reductions in injection-related risk behaviors from the IDEA SSP and highlights potential high priority groups, such as people experiencing homelessness, that may need additional intervention. In addition, improving syringe coverage among SSP clients may be an important factor in reducing behaviors that place individuals at risk for contracting HIV and HCV.

Application of Distributed Agent-based Modeling to Investigate Opioid Use Outcomes in Justice Involved Populations

Criminal justice involved (CJI) individuals with a history of opioid use disorder (OUD) are at high risk of overdose and death in the weeks following release from jail. We developed the Justice-Community Circulation Model (JCCM) to investigate OUD/CJI dynamics post-release and the effects of interventions on overdose deaths. The JCCM uses a synthetic agent-based model population of approximately 150,000 unique individuals that is generated using demographic information collected from multiple Chicago-area studies and data sets. We use a high-performance computing (HPC) workflow to implement a sequential approximate Bayesian computation algorithm for calibrating the JCCM. The calibration results in the simulated joint posterior distribution of the JCCM input parameters. The calibrated model is used to investigate the effects of a naloxone intervention for a mass jail release. The simulation results show the degree to which a targeted intervention focusing on recently released jail inmates can help reduce the risk of death from opioid overdose.

Breaching Trust: A Qualitative Study of Healthcare Experiences of People Who Use Drugs in a Rural Setting

Background: Increased drug use has disproportionately impacted rural areas across the U.S. People who use drugs are at risk of overdose and other medical complications, including infectious diseases. Understanding barriers to healthcare access for this often stigmatized population is key to reducing morbidity and mortality, particularly in rural settings where resources may be limited. Methods: We conducted 20 semi-structured interviews with people who use drugs, including 17 who inject drugs, in rural southern Illinois between June 2018 and February 2019. Interviews were analyzed using a modified grounded theory approach where themes are coded and organized as they emerge from the data. Results: Participants reported breaches of trust by healthcare providers, often involving law enforcement and Emergency Medical Services, that dissuaded them from accessing medical care. Participants described experiences of mistreatment in emergency departments, with one account of forced catheterization. They further recounted disclosures of protected health information by healthcare providers, including communicating drug test results to law enforcement and sharing details of counseling sessions with community members without consent. Participants also described a hesitancy common among people who use drugs to call emergency medical services for an overdose due to fear of arrest. Conclusion: Breaches of trust by healthcare providers in rural communities discouraged people who use drugs from accessing medical care until absolutely necessary, if at all. These experiences may worsen healthcare outcomes and further stigmatize this marginalized community. Structural changes including reforming and clarifying law enforcement's role in Emergency Departments as well as instituting diversion policies during arrests may help rebuild trust in these communities. Other possible areas for intervention include stigma training and harm reduction education for emergency medicine providers, as well as developing and implementing referral systems between Emergency Departments and local harm reduction providers and medically assisted drug treatment programs.

HIV Injection Risk Behaviors among HIV-Negative People Who Inject Drugs Experiencing Homelessness, 23 U.S. Cities

Despite recent declines in numbers of people who inject drugs (PWID) diagnosed with HIV, clusters of HIV among PWID are ongoing, especially among PWID experiencing homelessness. Using data from the National HIV Behavioral Surveillance in 2018, we evaluated the association between homelessness and injection risk and prevention behaviors among HIV-negative PWID who were recruited by respondent-driven sampling in 23 U.S. cities. Interviewers assessed sociodemographic characteristics, history of overdose, and behavioral risk and prevention factors for HIV. Adjusted prevalence ratios (aPR) and 95% CI were obtained using Poisson regression models. Of 10,614 HIV-negative PWID participants, 7275 (68.5%) reported experiencing homelessness. Homeless PWID were more likely than those who were not to be younger age, white, unemployed, without health insurance, in poverty, experiencing psychological distress, and incarcerated in the past 12 months. PWID experiencing homelessness were significantly more likely to report injection risk behaviors [share syringes/equipment (aPR = 1.26; 95% CI = 1.20-1.33), non-fatal opioid overdose (aPR = 1.64; 95% CI = 1.49-1.79)] and prevention behaviors [testing for HIV in past 12 months (aPR = 1.18; 95% CI = 1.12-1.24) and using syringe services programs (aPR = 1.09; 95% CI = 1.03-1.16)] than PWID not experiencing homelessness. Homelessness among PWID is associated with injection risk behaviors and non-fatal overdose.

Significant decrease in injection risk behaviours among participants in a needle exchange programme

Background and aims: Sharing of unsterile injection equipment contributes to transmission of hepatitis C virus (HCV), HIV and hepatitis B virus (HBV) among people who inject drugs (PWID) but is largely preventable through needle exchange programmes (NEP). Sweden has been one of the last countries in Europe to scale up access to NEP for PWID, who consequently have high prevalence rates of HCV and HIV. The aim of the study was to investigate demographic and drug-related determinants of injection risk behaviours, sharing of needle/syringe and paraphernalia, and patterns of change over time in subgroups of PWID participating in the Stockholm NEP.Methods: The Stockholm NEP started in 2013 as the first formal NEP in the region. A total of 2860 PWID were included in this prospective open cohort study. The association between demographic and drug-related determinants and injection risk behaviours were analysed at baseline and followed up at 6, 12, 24, 36 and 48 months post-enrolment.Results: The following factors were associated with high levels of injection risk behaviours at inclusion: female gender, homelessness, low education level, younger age, amphetamine use, not in opioid substitution therapy (OST), being HIV negative and being HCV positive. We found an overall significant decrease in injection risk behaviours over time among participants. Not previously investigated in depth, we found that subgroups of participants varied in degrees of injection risk behaviour reduction over time and that women decreased injection risk behaviours faster than men. Enrolment in OST, HIV positive and age <25 years at inclusion were not associated with a decrease in injection risk behaviours over time.Conclusions: In this prospective cohort study over 4 years, we found that NEP participation was associated with a significant decrease in injection risk behaviours.

Distributive Syringe Sharing and Use of Syringe Services Programs (SSPs) Among Persons Who Inject Drugs

Monitoring distributive syringe sharing (DSS) and syringe services program (SSP) use among persons who inject drugs (PWID) is important for HIV prevention. PWID aged ≥ 18 in 20 US cities were recruited for National HIV Behavioral Surveillance in 2015 using respondent-driven sampling, interviewed and offered HIV testing. Bivariate and multivariable analyses via log-linked Poisson regression with generalized estimating equations were conducted to examine associations between demographic and behavioral variables and DSS. Effect of SSP use on DSS by HIV sero-status was assessed by including an interaction between SSP and sero-status. Analyses were adjusted for sampling design. Among 10,402 PWID, 42% reported DSS. DSS was less likely to be reported among HIV-positive compared to HIV-negative PWID (aPR = 0.51, CI 0.45-0.60), and among those who primarily obtained syringes from SSPs versus those who did not (aPR = 0.82, 95% CI 0.77-0.88). After adjustment, those who primarily used SSPs were less likely to report DSS than those who did not among both HIV-negative PWID (aPR = 0.84, 95% CI 0.78-0.90) and HIV-positive PWID (aPR = 0.54, 95% CI 0.39-0.75). Findings support expansion of SSPs, and referrals to SSPs by providers working with PWID.

Modeling indicates efficient vaccine-based interventions for the elimination of hepatitis C virus among persons who inject drugs in metropolitan Chicago

BACKGROUND AND AIMS

Persons who inject drugs (PWID) are at highest risk for acquiring and transmitting hepatitis C (HCV) infection. The recent availability of oral direct-acting antiviral (DAA) therapy with reported cure rates >90% can prevent HCV transmission, making HCV elimination an attainable goal among PWID. The World Health Organization (WHO) recently proposed a 90% reduction in HCV incidence as a key objective. However, given barriers to the use of DAAs in PWID, including cost, restricted access to DAAs, and risk of reinfection, combination strategies including the availability of effective vaccines are needed to eradicate HCV as a public health threat. This study aims to model the cost and efficacy of a dual modality approach using HCV vaccines combined with DAAs to reduce HCV incidence by 90% and prevalence by 50% in PWID populations.

METHODS

We developed a mathematical model that represents the HCV epidemic among PWID and calibrated it to empirical data from metropolitan Chicago, Illinois. Four medical interventions were considered: vaccination of HCV naive PWID, DAA treatment, DAA treatment followed by vaccination, and, a combination of vaccination and DAA treatment.

RESULTS

The combination of vaccination and DAAs is the lowest cost-expensive intervention for achieving the WHO target of 90% incidence reduction. The use of DAAs without a vaccine is much less cost-effective with the additional risk of reinfection after treatment. Vaccination of naïve PWID alone, even when scaled-up to all reachable PWID, cannot achieve 90% reduction of incidence in high-prevalence populations due to infections occurring before vaccination. Similarly, the lowest cost-expensive way to halve prevalence in 15 years is through the combination of vaccination and DAAs.

CONCLUSIONS

The modeling results underscore the importance of developing an effective HCV vaccine and augmenting DAAs with vaccines in HCV intervention strategies in order to achieve efficient reductions in incidence and prevalence.

Feasibility of ecological momentary assessment to study mood and risk behavior among young people who inject drugs

AIMS

To test the acceptability and feasibility of ecological momentary assessment (EMA) of mood and injection risk behavior among young people who inject drugs (PWID), using mobile phones.

METHODS

Participants were 185 PWID age 18-35 recruited from two sites of a large syringe service program in Chicago. After completing a baseline interview, participants used a mobile phone app to respond to momentary surveys on mood, substance use, and injection risk behavior for 15 days. Participants were assigned to receive surveys 4, 5, or 6 times per day.

RESULTS

Participants were 68% male, 61% non-Hispanic white, 24% Hispanic, and 5% non-Hispanic Black. Out of 185 participants, 8% (n = 15) failed to complete any EMA assessments. Among 170 EMA responders, the mean number of days reporting was 10 (SD 4.7), the mean proportion of assessments completed was 0.43 (SD 0.27), and 76% (n = 130) completed the follow-up interview. In analyses adjusted for age and race/ethnicity, women were more responsive than men to the EMA surveys in days reporting (IRR = 1.33, 95% CI 1.13-1.56), and total number of surveys completed (IRR = 1.51, 95% CI 1.18-1.93). Homeless participants responded on fewer days (IRR = 0.76, 95% CI 0.64-0.90) and completed fewer surveys (IRR = 0.70, 95% CI 0.54-0.91), and were less likely to return for follow-up (p = 0.016). EMA responsiveness was not significantly affected by the number of assigned daily assessments.

CONCLUSIONS

This study demonstrated high acceptability and feasibility of EMA among young PWID, with up to 6 survey prompts per day. However, homelessness significantly hampered successful participation.

Strategies for the elimination of hepatitis C virus infection as a public health threat in the United States

Purpose of Review

Direct-acting antiviral regimens for chronic hepatitis C virus (HCV) became available in 2014, and these highly curative therapies have the potential to reduce HCV-associated morbidity and mortality, decrease transmission, and eliminate HCV infection as a public health problem. This review summarizes the recommendations by the National Academies of Sciences, Engineering, and Medicine for a US strategy for HCV elimination.

Recent Findings

To achieve proposed targets of reducing HCV incidence by 90% and decreasing HCV-related mortality by 60% by 2030, there is a critical need to improve HCV diagnosis and linkage to care; reduce HCV-related disease by antiviral treatment scale-up; reduce HCV incidence; and strengthen HCV surveillance to determine achievement of HCV elimination targets over time.

Summary

While HCV elimination is feasible, success of this national effort will require ongoing collaboration and critical resource investment by key stakeholders, including medical and public health communities, legislators, community organizers, and patient advocates.

Cost-effectiveness of alternative strategies for provision of HIV preexposure prophylaxis for people who inject drugs

BACKGROUND

Oral HIV preexposure prophylaxis (PrEP) has been recommended as a means of HIV prevention among people who inject drugs (PWIDs) but, at current prices, is unlikely to be cost-effective for all PWID.

OBJECTIVE

To determine the cost-effectiveness of alternative strategies for enrolling PWID in PrEP.

DESIGN

Dynamic network model that captures HIV transmission and progression among PWID in a representative US urban center.

OUTCOME MEASURES

HIV infections averted, discounted costs and quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios.

INTERVENTION

We assume 25% PrEP coverage and investigate four strategies: first, random PWID are enrolled (Unselected Enrollment); second, individuals are randomly selected and enrolled together with their partners (Enroll Partners); third, individuals with the highest number of sexual and needle-sharing partnerships are enrolled (Most Partners); fourth, individuals with the greatest number of infected partners are enrolled (Most Positive Partners).

RESULTS

PrEP can achieve significant health benefits: compared with the status quo of no PrEP, the strategies gain 1114 QALYs (Unselected Enrollment), 2194 QALYs (Enroll Partners), 2481 QALYs (Most Partners), and 3046 QALYs (Most Positive Partners) over 20 years in a population of approximately 8500 people. The incremental cost-effectiveness ratio of each strategy compared with the status quo (cost per QALY gained) is $272 000 (Unselected Enrollment), $158 000 (Enroll Partners), $124 000 (Most Partners), and $101 000 (Most Positive Partners). All strategies except Unselected Enrollment are cost-effective according to WHO criteria.

CONCLUSION

Selection of high-risk PWID for PrEP can improve the cost-effectiveness of PrEP for PWID.

Declining rates of health problems associated with crack smoking during the expansion of crack pipe distribution in Vancouver, Canada

Background

Crack cocaine smoking is associated with an array of negative health consequences, including cuts and burns from unsafe pipes, and infectious diseases such as HIV. Despite the well-established and researched harm reduction programs for injection drug users, little is known regarding the potential for harm reduction programs targeting crack smoking to reduce health problems from crack smoking. In the wake of recent crack pipe distribution services expansion, we utilized data from long running cohort studies to estimate the impact of crack pipe distribution services on the rates of health problems associated with crack smoking in Vancouver, Canada.

Methods

Data were derived from two prospective cohort studies of community-recruited people who inject drugs in Vancouver between December 2005 and November 2014. We employed multivariable generalized estimating equations to examine the relationship between crack pipe acquisition sources and self-reported health problems associated with crack smoking (e.g., cut fingers/sores, coughing blood) among people reported smoking crack.

Results

Among 1718 eligible participants, proportions of those obtaining crack pipes only through health service points have significantly increased from 7.2% in 2005 to 62.3% in 2014 (p < 0.001), while the rates of reporting health problems associated with crack smoking have significantly declined (p < 0.001). In multivariable analysis, compared to those obtaining pipes only through other sources (e.g., on the street, self-made), those acquiring pipes through health service points only were significantly less likely to report health problems from smoking crack (adjusted odds ratio: 0.82; 95% confidence interval: 0.73–0.93).

Conclusions

These findings suggest that the expansion of crack pipe distribution services has likely served to reduce health problems from smoking crack in this setting. They provide evidence supporting crack pipe distribution programs as a harm reduction service for crack smokers.

Reducing HIV infection in people who inject drugs is impossible without targeting recently-infected subjects

OBJECTIVE

Although our understanding of viral transmission among people who inject drugs (PWID) has improved, we still know little about when and how many times each injector transmits HIV throughout the duration of infection. We describe HIV dynamics in PWID to evaluate which preventive strategies can be efficient.

DESIGN

Due to the notably scarce interventions, HIV-1 spread explosively in Russia and Ukraine in 1990s. By studying this epidemic between 1995 and 2005, we characterized naturally occurring transmission dynamics of HIV among PWID.

METHOD

We combined publicly available HIV pol and env sequences with prevalence estimates from Russia and Ukraine under an evolutionary epidemiology framework to characterize HIV transmissibility between PWID. We then constructed compartmental models to simulate HIV spread among PWID.

RESULTS

In the absence of interventions, each injector transmits on average to 10 others. Half of the transmissions take place within 1 month after primary infection, suggesting that the epidemic will expand even after blocking all the post-first month transmissions. Primary prevention can realistically target the first month of infection, and we show that it is very efficient to control the spread of HIV-1 in PWID. Treating acutely infected on top of primary prevention is notably effective.

CONCLUSION

As a large proportion of transmissions among PWID occur within 1 month after infection, reducing and delaying transmissions through scale-up of harm reduction programmes should always form the backbone of HIV control strategies in PWID. Growing PWID populations in the developing world, where primary prevention is scarce, constitutes a public health time bomb.

Association of opioid agonist therapy with the initiation of antiretroviral therapy - a systematic review

OBJECTIVES

People who inject drugs are at high risk of HIV infection but often face barriers in accessing medical care including access to antiretroviral therapy (ART). Evidence is available about the effectiveness of opioid agonist therapy on drug dependency and risk behaviors. However, it remains scattered regarding access to ART among HIV-positive people who inject drugs. We conducted a systematic review to examine the association of opioid agonist therapy with ART initiation among HIV-positive people who inject drugs.

METHODS

We searched the literature for evidence from seven databases. We conducted a narrative synthesis and meta-analysis to examine the association of opioid agonist therapy with ART initiation.

RESULTS

Five out of 2,901 identified studies met the inclusion criteria. Three out of five studies reported that, HIV-positive people receiving opioid agonist therapy initiated ART more than those not receiving opioid agonist therapy. In meta-analysis, opioid agonist therapy was associated with ART initiation among HIV positive people who inject drugs (pooled odds ratio: 1.68; 95% confidence interval: 1.03-2.73).

CONCLUSIONS

Opioid agonist therapy is positively associated with ART initiation among HIV-positive people who inject drugs. It is important to scale up opioid agonist therapy among people who inject drugs to improve their ART initiation.

Modeling a dynamic bi-layer contact network of injection drug users and the spread of blood-borne infections

Injection drug users (IDUs) are at high risk of acquiring and spreading various blood-borne infections including human immunodeficiency virus (HIV), hepatitis C virus (HCV), hepatitis B virus (HBV) and a number of sexually transmitted infections. These infections can spread among IDUs via risky sexual and needle-sharing contacts. To accurately model the spread of such contagions among IDUs, we build a bi-layer network that captures both types of risky contacts. We present methodology for inferring important model parameters, such as those governing network structure and dynamics, from readily available data sources (e.g., epidemiological surveys). Such a model can be used to evaluate the efficacy of various programs that aim to combat drug addiction and contain blood-borne diseases among IDUs. The model is especially useful for evaluating interventions that exploit the structure of the contact network. To illustrate, we instantiate a network model with data collected by a needle and syringe program in Chicago. We model sexual and needle-sharing contacts and the consequent spread of HIV and HCV. We use the model to evaluate the potential effects of a peer education (PE) program under different targeting strategies. We show that a targeted PE program would avert significantly more HIV and HCV infections than an untargeted program, highlighting the importance of reaching individuals who are centrally located in contact networks when instituting prevention programs.

Agent-Based Model Forecasts Aging of the Population of People Who Inject Drugs in Metropolitan Chicago and Changing Prevalence of Hepatitis C Infections

People who inject drugs (PWID) are at high risk for blood-borne pathogens transmitted during the sharing of contaminated injection equipment, particularly hepatitis C virus (HCV). HCV prevalence is influenced by a complex interplay of drug-use behaviors, social networks, and geography, as well as the availability of interventions, such as needle exchange programs. To adequately address this complexity in HCV epidemic forecasting, we have developed a computational model, the Agent-based Pathogen Kinetics model (APK). APK simulates the PWID population in metropolitan Chicago, including the social interactions that result in HCV infection. We used multiple empirical data sources on Chicago PWID to build a spatial distribution of an in silico PWID population and modeled networks among the PWID by considering the geography of the city and its suburbs. APK was validated against 2012 empirical data (the latest available) and shown to agree with network and epidemiological surveys to within 1%. For the period 2010–2020, APK forecasts a decline in HCV prevalence of 0.8% per year from 44(±2)% to 36(±5)%, although some sub-populations would continue to have relatively high prevalence, including Non-Hispanic Blacks, 48(±5)%. The rate of decline will be lowest in Non-Hispanic Whites and we find, in a reversal of historical trends, that incidence among non-Hispanic Whites would exceed incidence among Non-Hispanic Blacks (0.66 per 100 per years vs 0.17 per 100 person years). APK also forecasts an increase in PWID mean age from 35(±1) to 40(±2) with a corresponding increase from 59(±2)% to 80(±6)% in the proportion of the population >30 years old. Our studies highlight the importance of analyzing subpopulations in disease predictions, the utility of computer simulation for analyzing demographic and health trends among PWID and serve as a tool for guiding intervention and prevention strategies in Chicago, and other major cities.

Barriers to practicing risk reduction strategies among people who inject drugs

INTRODUCTION AND AIMS

People who inject drugs (PWID) engage in practices that put them at risk for various infections and overdose. The primary aim of this study was to examine common barriers to engaging in two risk reduction practices - cleaning one's skin at the injection site and always using new needles to inject - among heroin injectors in Denver, CO.

METHOD

In 2010, 48 PWIDs were recruited through street outreach and completed a structured interview that included questions on the frequency of specific risk reduction practices (skin cleaning and using new needles) and barriers associated with these practices.

RESULTS

Though many of the reported barriers were similar across the two practices, the most common barriers associated with skin cleaning included being in withdrawal and not being prepared with materials prior to injection. Fear of being arrested and being in withdrawal were most frequently reported for using new needles. Multivariate and t-test analyses demonstrated that individuals who skin cleaned and used new needles more frequently reported less barriers to these practices.

CONCLUSIONS

Participants reported a number of barriers to risk reduction, including those that are within the personal control of the injector, barriers that are consequences of addiction or psychological problems, and those that are structural or a function of the risk environment. Statistical analysis found that PWIDs who were more likely to skin clean and use new needles reported less barriers. Addressing barriers when intervening with PWID appears important to increase the success of risk reduction interventions.

Prevalence and correlates of neck injection among people who inject drugs in Tijuana, Mexico

INTRODUCTION AND AIMS

Injecting drugs in the neck has been related to adverse health conditions such as jugular vein thrombosis, deep neck infections, aneurysm, haematomas, airway obstruction, vocal cord paralysis and wound botulism, among others. We identified prevalence and correlates of neck injection among people who inject drugs (PWID) in Tijuana, Mexico.

DESIGN AND METHODS

Beginning in 2011, PWID aged ≥18 years who injected drugs within the last month were recruited into a prospective cohort. At baseline and semi-annually, PWID completed interviewer-administered surveys soliciting data on drug-injecting practices. Logistic regression was used to identify predictors of injecting in the neck as the most frequent injection site at a single visit.

RESULTS

Of 380 PWID, 35.3% injected in the neck at least once in the past 6 months, among whom 71.6% reported it as their most common injection site, the most common injecting site after the arms (47%). Controlling for age, years injecting and injecting frequency, injecting heroin and methamphetamine two or more times per day and having sought injection assistance were associated with injecting in the neck [adjusted odds ratios (AOR): 2.12; 95% confidence intervals (CI): 1.27-3.53 and AOR: 2.65; 95% CI: 1.52-4.53 respectively].

DISCUSSION AND CONCLUSIONS

Injecting in the neck was very common among PWID in Tijuana and was associated with polydrug use and seeking injection assistance. Tailoring harm reduction education interventions for individuals who provide injection assistance ('hit doctors') may allow for the dissemination of safe injecting knowledge to reduce injection-related morbidity and mortality.

The Flawed Reliance on Randomized Controlled Trials in Studies of HIV Behavioral Prevention Interventions for People Who Inject Drugs and Other Populations

This article discusses ways in which randomized controlled trials do not accurately measure the impact of HIV behavioral interventions. This is because: 1. Such trials measure the wrong outcomes. Behavior change may have little to do with changes in HIV incidence since behavior change in events between HIV-concordant people have no impact on incidence. Even more important, the comparison of HIV incidence rates between study arms of individual-level RCTs does not measure the true outcome of interest-whether or not the intervention reduces HIV transmission at the community level. This is because this comparison cannot measure the extent to which the intervention stops transmission by HIV-infected people in the study to those outside it. (And this is made even worse if HIV-infected are excluded from the evaluation of the intervention.) 2. There are potential harms implicit in most cognitively oriented behavioral interventions that are not measured in current practice and may not be measurable using RCTs. Intervention trials often reinforce norms and values of individual self-protection. They rarely if ever measure whether doing this reduces community trust, solidarity, cohesion, organization, or activism in ways that might facilitate HIV transmission. 3. Many interventions are not best conceived of as interventions with individuals but rather with networks, cultures of risks, or communities. As such, randomizing individuals leads to effective interventions that diffuse protection through a community; but these are evaluated as ineffective because the changes diffuse to the control arm, which leads to systematic and erroneous reductions in the evaluated effectiveness as RCTs measure it. The paper ends by discussing research designs that are superior to individual-level RCTs at measuring whether an intervention reduces or increases new HIV transmission.

Syringe exchange in the United States: a national level economic evaluation of hypothetical increases in investment

To examine whether increasing investment in needle/syringe exchange programs (NSPs) in the US would be cost-effective for HIV prevention, we modeled HIV incidence in hypothetical cases with higher NSP syringe supply than current levels, and estimated number of infections averted, cost per infection averted, treatment costs saved, and financial return on investment. We modified Pinkerton's model, which was an adaptation of Kaplan's simplified needle circulation theory model, to compare different syringe supply levels, account for syringes from non-NSP sources, and reflect reduction in syringe sharing and contamination. With an annual $10 to $50 million funding increase, 194-816 HIV infections would be averted (cost per infection averted $51,601-$61,302). Contrasted with HIV treatment cost savings alone, the rate of financial return on investment would be 7.58-6.38. Main and sensitivity analyses strongly suggest that it would be cost-saving for the US to invest in syringe exchange expansion.

Prevalence of HIV infection and risk behaviors among younger and older injecting drug users in the United States, 2009

This study compared HIV sero-prevalence and risk behaviors between younger and older injecting drug users (IDUs). IDUs aged ≥18 years were interviewed for the 2009 National HIV Behavioral Surveillance System. Using GEE regression, we assessed characteristics of younger (18-29 years) and older (≥30 years) IDUs, and factors associated with past 12-month receptive syringe sharing and unprotected sex (vaginal/anal). Of 10,090 participants, 10 % were younger. HIV sero-prevalence was lower among younger than older IDUs (4 vs. 10 %, p = 0.001). Younger IDUs were more likely (p ≤ 0.002) to be non-black race/ethnicity, report higher household income, homelessness, being arrested and to engage in receptive syringe sharing and unprotected sex. In multivariable models, age remained associated (p < 0.001) with receptive syringe sharing (aPR = 1.14, 95 % CI1.07-1.22) and unprotected sex (aPR = 1.10, 95 % CI1.06-1.14). Although younger IDUs had lower HIV prevalence, their behaviors place them at increased risk of HIV infection and could lead to a rapid spread in this susceptible population.

Dual HIV risk: receptive syringe sharing and unprotected sex among HIV-negative injection drug users in New York City

HIV-negative injection drug users (IDUs) who engage in both receptive syringe sharing and unprotected sex ("dual HIV risk") are at high risk of HIV infection. In a cross-sectional study conducted in New York City in 2009, active IDUs aged ≥18 years were recruited using respondent-driven sampling, interviewed, and tested for HIV. Participants who tested HIV-negative and did not self-report as positive were analyzed (N = 439). Adjusted odds ratios (aOR) and 95 % confidence intervals (95 % CI) were estimated using multinomial logistic regression. The sample was: 77.7 % male; 54.4 % Hispanic, 36.9 % white, and 8.7 % African-American/black. Dual risk was engaged in by 26.2 %, receptive syringe sharing only by 3.2 %, unprotected sex only by 49.4 %, and neither by 21.2 %. Variables independently associated with engaging in dual risk versus neither included Hispanic ethnicity (vs. white) (aOR = 2.0, 95 % CI = 1.0-4.0), married or cohabiting (aOR = 6.3, 95 % CI = 2.5-15.9), homelessness (aOR = 3.4, 95 % CI = 1.6-7.1), ≥2 sex partners (aOR = 8.7, 95 % CI = 4.4-17.3), ≥2 injecting partners (aOR = 2.9, 95 % CI = 1.5-5.8), and using only sterile syringe sources (protective) (aOR = 0.5, 95 % CI = 0.2-0.9). A majority of IDUs engaged in HIV risk behaviors, and a quarter in dual risk. Interventions among IDUs should simultaneously promote the consistent use of sterile syringes and of condoms.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Reducing the health consequences of opioid addiction in primary care

Addiction to prescription opioids is prevalent in primary care settings. Increasing prescription opioid use is largely responsible for a parallel increase in overdose nationally. Many patients most at risk for addiction and overdose come into regular contact with primary care providers. Lack of routine addiction screening results in missed treatment opportunities in this setting. We reviewed the literature on screening and brief interventions for addictive disorders in primary care settings, focusing on opioid addiction. Screening and brief interventions can improve health outcomes for chronic illnesses including diabetes, hypertension, and asthma. Similarly, through the use of screening and brief interventions, patients with addiction can achieve improved health outcome. A spectrum of low-threshold care options can reduce the negative health consequences among individuals with opioid addiction. Screening in primary care coupled with short interventions, including motivational interviewing, syringe distribution, naloxone prescription for overdose prevention, and buprenorphine treatment are effective ways to manage addiction and its associated risks and improve health outcomes for individuals with opioid addiction.

HCV infection prevalence lower than expected among 18-40-year-old injection drug users in San Diego, CA

San Diego, California shares the world's busiest land border crossing with Tijuana, Mexico-a city where 95 % of injection drug users (IDUs) test hepatitis C virus (HCV) antibody-positive. Yet, little is known about the prevalence and risk behaviors for HCV among IDUs in San Diego. In 2009-2010, 18-40-year-old IDUs in San Diego County completed a risk assessment interview and serologic testing for HCV and HIV infection. Recruitment involved respondent-driven sampling, venue-based sampling at a syringe exchange program, and convenience sampling. Correlates of HCV infection were identified by multivariable logistic regression. Among 510 current IDUs, 26.9 % (95 % CI 23.0-30.7 %) and 4.2 % (95 % CI 2.4-5.9 %) had been infected with HCV and HIV, respectively. Overall, median age was 28 years; 74 % were male; 60 % white and 29 % Hispanic; and 96 % were born in the U.S. Median years of injecting was 6; 41 % injected daily; 60 % injected heroin most often; 49 % receptively shared syringes and 68 % shared other injection paraphernalia; and only 22 % reported always using new syringes in the past 3 months. Two thirds had ever traveled to Mexico and 19 % injected in Mexico. HCV infection was independently associated with sharing injection paraphernalia (adjusted odds ratio [AOR] = 1.69) and SEP use (AOR = 2.17) in the previous 3 months, lifetime history of drug overdose (AOR = 2.66), and increased years of injecting (AOR = 2.82, all P values <0.05). Controlling for recruitment method did not alter results. HCV infection prevalence among IDUs in San Diego was modest compared to other US cities and much lower than Tijuana. Given that known individual-level HCV risk factors were common in San Diego, the city's lower HCV prevalence might be due to differences in social and structural factors between the cities.

Development of a risk reduction intervention to reduce bacterial and viral infections for injection drug users

Bacterial infections are widespread problems among drug injectors, requiring novel preventive intervention. As part of a NIDA-funded study, we developed an intervention based on the Information-Motivation-Behavioral Skills model, past research, injection hygiene protocols, and data collected from focus groups with 32 injectors in Denver in 2009. Qualitative responses from focus groups indicated that most participants had experienced skin abscesses and believed that bacterial infections were commonly a result of drug cut, injecting intramuscularly, and reusing needles. Access to injection supplies and experiencing withdrawal were the most frequently reported barriers to utilizing risk reduction. Implications for intervention development are discussed.

Uptake of paraphernalia from injecting equipment provision services and its association with sharing of paraphernalia among injecting drug users in Scotland

BACKGROUND

There has been a significant increase in the provision of injecting paraphernalia from Scottish injecting equipment provision (IEP) services. However, there is currently a lack of evidence on whether uptake of paraphernalia has any impact on paraphernalia sharing among injecting drug users (IDU). The aim of this study was to examine the factors associated with paraphernalia sharing; in particular, whether uptake of filters, spoons and sterile water from IEPs is associated with a reduction in the sharing of these items.

METHODS

A cross-sectional voluntary anonymous survey of 2037 IDUs was administered during 2008-2009. Participants were asked whether they had shared filters, spoons or water (paraphernalia) in the previous 6 months, and their uptake of these items from an IEP during an average week in the previous 6 months.

RESULTS

Self-reported uptake of paraphernalia in an average week during the previous 6 months was associated with reduced odds of sharing paraphernalia: (i) uptake of >30 filters was associated with a reduced odds of sharing filters (adjusted odds ratio (AOR) 0.50, 95% confidence interval 0.32-0.79); (ii) uptake of >30 spoons was associated with a reduced odds of sharing spoons (AOR 0.46, 95% confidence interval 0.28-0.74); and (iii) uptake of sterile water was associated with a reduced odds of sharing water (AOR 0.36, 95% confidence interval 0.22-0.61) compared to no uptake of each of these items.

CONCLUSIONS

Uptake of paraphernalia appears to be associated with safer injecting practice. Further research is needed to establish the impact of paraphernalia provision on HCV transmission.

Skin and needle hygiene intervention for injection drug users: results from a randomized, controlled Stage I pilot trial

A new skin and needle hygiene intervention, designed to reduce high-risk injection practices associated with bacterial and viral infections, was tested in a pilot, randomized controlled trial. Participants included 48 active heroin injectors recruited through street outreach and randomized to either a 2-session intervention or an assessment-only condition (AO) and followed up for 6 months. The primary outcome was skin- and needle-cleaning behavioral skills measured by videotaped demonstration. Secondary outcomes were high-risk injection practices, intramuscular injection, and bacterial infections. Intervention participants had greater improvements on the skin (d = 1.00) and needle-cleaning demonstrations (d = .52) and larger reductions in high-risk injection practices (d = .32) and intramuscular injection (d = .29), with a lower incidence rate of bacterial infections (hazard ratio = .80), at 6 months compared with AO. The new intervention appears feasible and promising as a brief intervention to reduce bacterial and viral risks associated with drug injection.

Problem recognition, intention to stop use, and treatment use among regular heroin injectors

This study investigated frequency of recent use as an explanatory variable in problem recognition and intention to stop use among regular injection heroin users. Data from the NEURO-HIV Epidemiologic Study, an investigation of neuropsychological and social-behavioral risk factors for HIV and hepatitis A, B, and C among injection and noninjection drug users, were used in the analyses. Participants (N = 337) consisted of those who reported injecting heroin daily or nearly daily for a period of 3 months. Multiple linear regression analysis revealed that frequency of recent injection drug use predicted problem recognition (β = .17), but not intention to stop use; although marginal, being female (β = .15), and homeless (β = .14) contributed to intention to stop use. Past 6-month treatment participation was 48%, and current treatment enrollment was 26% among study participants. This study highlights the importance of capitalizing on injection drug users' recent use as a mechanism for treatment interventions.

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

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

A treatment reengagement intervention for syringe exchangers

Poor sustained treatment engagement limits the effectiveness of all modalities of substance abuse treatment. This study evaluated the efficacy of a novel treatment reengagement intervention for a subset of syringe-exchange program (SEP) participants (N = 113) that had enrolled in treatment as part of a 4-month clinical trial (M. Kidorf et al., 2009). Three reengagement conditions for participants leaving treatment were compared. Motivational referral condition (MRC) participants (n = 31) could attend group sessions that focused on renewing treatment interest. MRC plus incentive (MRC + I) participants (n = 49) could receive modest monetary incentives for attending these sessions and reenrolling in treatment. Standard referral condition participants (n = 33) could not attend groups or receive incentives. Across a 1-year observation window, almost all study participants (86%) were discharged from treatment. MRC + I participants attended more group sessions than MRC participants and were considerably more likely to reenroll in treatment than participants in the other study conditions. Reengagement strategies can further enhance the public health benefits of SEPs by increasing rates of treatment participation over time.

Correlates of risky injection practices among past-year injection drug users among the US general population

BACKGROUND

With an estimated 1 million active injection drug users (IDUs), injection drug use continues to be a public health concern in the United States. Risky injection practices have been associated with the transmission of HIV, Hepatitis B and C, as well as other skin and soft tissue infections.

METHODS

We used data from 463 respondents, aged 18 and older, who were past-year IDUs in the 2005-2008 National Survey of Drug Use and Health (NSDUH). We investigated correlates of risky injection behavior among these recent IDUs.

RESULTS

Older age (≥ 35 versus 18-25) was associated with reusing one's own needle at last injection (aOR=1.80 [1.02-3.17], as were past year heroin (aOR=2.59 [1.18-5.66]) and cocaine injection (aOR=2.17 [1.13-4.15]). Past year crack cocaine use was positively associated with not cleaning needles with bleach (aOR=2.18 [1.10-4.33]). Past year cocaine injection was associated with obtaining needles in a risky manner (aOR=2.29 [1.23-4.25]). Methamphetamine injection was associated with obtaining needles in less risky ways (aOR=0.41 [0.20-0.84]).

CONCLUSION

Our findings indicate that some IDUs are continuing to engage in high risk injection behaviors. The identification of potential at-risk populations of IDUs may have implications for harm reduction interventions and HIV prevention programs.

Benefits of concurrent syringe exchange and substance abuse treatment participation

Participation in syringe exchange programs (SEPs) is associated with many individual and public health benefits but may have little impact on reducing drug use without concurrent treatment engagement. This study evaluated rates of drug use, other risk behaviors, and illegal activities in newly registered SEP participants (N = 240) enrolled versus not enrolled in substance abuse treatment over a 4-month observation window and examined the effect of days in treatment on these outcomes. After controlling for baseline differences, SEP registrants enrolled in treatment (n = 113) reported less days of opioid and cocaine use, injection drug use, illegal activities, and incarceration than those not enrolled in treatment (n = 127). For those enrolled in treatment, days of treatment was strongly correlated with each of these outcomes. These findings provide good evidence for a dose-response effect of treatment in syringe exchangers and suggest that substance abuse treatment significantly expands the harm reduction benefits of SEP participation.

Continuing HIV risk in New York City injection drug users: the association of syringe source and syringe sharing

Sterile syringe access is an important means to reduce HIV risk, but many injection drug users (IDU) who obtain syringes from sterile sources continue to share syringes. We examined the factors associated with continuing syringe sharing in New York City. We recruited 500 active IDU in 2005 through respondent-driven sampling. In multiple logistic regression, not obtaining all syringes in the past year exclusively from sterile sources was associated with increased syringe sharing. Ensuring adequate syringe availability as well as engaging and retaining nonusers and inconsistent users in sterile syringe services may increase sterile syringe access and decrease syringe sharing.

The provision of non-needle/syringe drug injecting paraphernalia in the primary prevention of HCV among IDU: a systematic review

BACKGROUND

Sharing drug injecting paraphernalia other than needles and syringes (N/S) has been implicated in the transmission of Hepatitis C virus (HCV) among injecting drug users (IDU). We aimed to determine whether the provision of sterile non-N/S injecting paraphernalia reduces injecting risk behaviours or HCV transmission among IDU.

METHODS

A systematic search of seven databases and the grey literature for articles published January 1989-February 2010 was undertaken. Thirteen studies (twelve observational and one non-randomized uncontrolled pilot intervention) were identified and appraised for study design and quality by two investigators.

RESULTS

No studies examined the association between the provision of non-N/S injecting paraphernalia and incident HCV infection. One cross-sectional study found that individuals who frequently, compared to those who infrequently, used sterile cookers and water, were less likely to report prevalent HCV infection. Another found no association between the uptake of sterile non-N/S injecting paraphernalia and self-reported sharing of this paraphernalia. The remaining observational studies used attendance at needle and syringe exchange programmes (NSP) or safer injection facilities (SIF) that provided non-N/S injecting paraphernalia as a proxy measure. Eight studies presented adjusted odds ratios, ranging from 0.3 to 0.9, suggesting a reduced likelihood of self-reported sharing of non-N/S injecting paraphernalia associated with use of NSP or SIF. There was substantial uncertainty associated with these estimates however. Three unadjusted studies reported a reduction in the prevalence of sharing of non-N/S injecting paraphernalia over time among NSP users. Only one study reported an adjusted temporal trend in the prevalence of sharing non-N/S injecting paraphernalia, finding higher rates among non-NSP users than NSP users at each time point, and a greater reduction in sharing among non-NSP than NSP users over time. Study limitations included the use of convenience samples, self-reported exposure and outcome measures, flawed classification of the exposed and unexposed groups, and inadequate adjustment for potential confounding variables.

CONCLUSIONS

The evidence to demonstrate that the provision of sterile non-N/S injecting paraphernalia reduces HCV transmission or modifies injecting risk behaviours is currently limited by an insufficient volume and quality of studies. Further research is required to inform practice and policy in this area.

Lessons learned from a peri-urban needle exchange

Background

Injection drug users continue to be at high risk of HIV and HCV. Research has shown that needle exchange programs (NEP) decrease injection frequency, reduce syringe reuse, and reduce needle sharing, though some results have been mixed.

Methods

This evaluation of a small, peri-urban, legal NEP near Ypsilanti, Michigan describes the operation of the NEP and its clients. It uses interviews conducted with NEP participants between 2003 and 2006, describing the population served by the program, and draws on limited comparisons between matched baseline and follow-up measures as well as aggregate baseline and follow-up comparisons.

Results

The HIV/AIDS Resource Center (HARC) Harm Reduction NEP serves a diverse population from a wide geographical area. NEP participants at follow-up reused their syringes significantly fewer times before getting new ones, were significantly less likely to report giving another IDU a previously used syringe, and were more likely to clean their skin with alcohol either before or after injecting than the baseline comparison group.

Conclusions

The limited data presented here suggest that a NEP can be an effective method of harm reduction even in low-volume, non-urban settings and are an important venue for intervention in peri-urban areas.

Race and distance effects on regular syringe exchange program use and injection risks: a geobehavioral analysis

OBJECTIVES

We conducted "geobehavioral" analyses by race to understand how distances among injection drug users' (IDUs') residences, drug purchase and use locations, and syringe exchange programs (SEPs) are associated with injection behaviors.

METHODS

Data were from the HIV Prevention Trial Network 037 (2002-2006) site in Philadelphia, Pennsylvania, a randomized study evaluating the efficacy of a network-oriented HIV prevention intervention for IDUs. At prescreening, participants were asked the nearest intersections to their residence, where they buy and use drugs, and about their injection behaviors.

RESULTS

Geographic distances had independent and interactive effects on injection risk behaviors and SEP use. Blacks, regardless of distance, were less likely than Whites to inject in public places (odds ratio [OR] = 0.62; 95% confidence interval [CI] = 0.43, 0.90), to use syringes after someone else (OR = 0.27; 95% CI = 0.19, 0.38), and to access syringes from SEPs (OR = 2.08; 95% CI = 1.48, 2.92). Latinos' injection behaviors were more distance-dependent than Blacks' or Whites'.

CONCLUSIONS

Distances among IDUs' homes, drug purchase and injecting sites, and prevention resources affected safe injection practices differentially by race. Understanding individuals' geographic relation to the risks and resources that surround them is an important aspect of understanding effects of the environment on health and behavior and the development of targeted interventions.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Utilization patterns and correlates of retention among clients of the needle exchange program in Baltimore, Maryland

NEP effectiveness at a population level depends on several factors, including the number of injection drug users (IDUs) retained, or consistently accessing services. Patterns of retention in the Baltimore Needle Exchange Program (BNEP) from 1994 to 2006 were calculated using enrollment surveys and client records. We used Andersen's Behavioral Model of Health Services Use to frame our examination of factors associated with retention. Client retention was measured in two ways: whether a client returned to the exchange within 12 months of enrollment and how many times a client returned within these 12 months. BNEP clients (N=12,388) were predominantly male (69%), African-American (73%), and >or=age 30 (86%). Nearly two-thirds (64%) of clients returned within 12 months of their first BNEP visit. The median number of return visits per client within 12 months was one (IQR: 0-5). Young age (<30), being married, having an injection drug use history of less than 20 years, and living farther from the BNEP site were characteristics independently associated with both measures of low retention in multivariate analysis. Among younger injectors, geographical proximity was a particularly important predictor of retention. Further insight into the influence of these factors may help in developing programmatic changes that will be effective in increasing retention.

Greater drug injecting risk for HIV, HBV, and HCV infection in a city where syringe exchange and pharmacy syringe distribution are illegal

Comparing drug-injecting risk between cities that differ in the legality of sterile syringe distribution for injection drug use provides a natural experiment to assess the efficacy of legalizing sterile syringe distribution as a structural intervention to prevent human immunodeficiency virus (HIV) and other parenterally transmitted infections among injection drug users (IDUs). This study compares the parenteral risk for HIV and hepatitis B (HBV) and C (HCV) infection among IDUs in Newark, NJ, USA, where syringe distribution programs were illegal during the period when data were collected, and New York City (NYC) where they were legal. IDUs were nontreatment recruited, 2004-2006, serotested, and interviewed about syringe sources and injecting risk behaviors (prior 30 days). In multivariate logistic regression, adjusted odds ratios (AOR) and 95% confidence intervals (95% CI) for city differences are estimated controlling for potential city confounders. IDUs in Newark (n = 214) vs. NYC (n = 312) were more likely to test seropositive for HIV (26% vs. 5%; AOR = 3.2; 95% CI = 1.6, 6.1), antibody to the HBV core antigen (70% vs. 27%; AOR = 4.4; 95% CI = 2.8, 6.9), and antibody to HCV (82% vs. 53%; AOR = 3.0; 95% CI = 1.8, 4.9), were less likely to obtain syringes from syringe exchange programs or pharmacies (AOR = 0.004; 95% CI = 0.001, 0.01), and were more likely to obtain syringes from street sellers (AOR = 74.0; 95% CI = 29.9, 183.2), to inject with another IDU's used syringe (AOR = 2.3; 95% CI = 1.1, 5.0), to reuse syringes (AOR = 2.99; 95% CI = 1.63, 5.50), and to not always inject once only with a new, sterile syringe that had been sealed in a wrapper (AOR = 5.4; 95% CI = 2.9, 10.3). In localities where sterile syringe distribution is illegal, IDUs are more likely to obtain syringes from unsafe sources and to engage in injecting risk behaviors. Legalizing and rapidly implementing sterile syringe distribution programs are critical for reducing parenterally transmitted HIV, HBV, and HCV among IDUs.