Use of an illegal syringe exchange and injection-related risk behaviors among street-recruited injection drug users in Oakland, California, 1992 to 1995

Syringe Coverage Among People Who Inject Drugs in West Virginia, USA

Ensuring people who inject drugs (PWID) have ≥ 100% sterile syringe coverage (i.e., persons have access to a sterile syringe for all injections) is optimal for HIV prevention. Existing syringe coverage literature is informative, yet little work has examined syringe coverage among PWID in rural communities. Using data from a 2018 PWID population estimation study conducted in a rural county in West Virginia, we used logistic regression to identify correlates of adequate sterile syringe coverage (at least 100%). A minority (37%) of PWID reported having adequate syringe coverage. Factors inversely associated with adequate syringe coverage included having recently (past 6 months): engaged in transactional sex work, shared syringes, and injected fentanyl. Having exclusively acquired syringes from a syringe services program was associated with increased odds of adequate syringe coverage. Rural PWID may benefit from tailored interventions designed to increase sterile syringe access.

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.

Comparing Injecting Risk Behaviors of Long-Term Injectors with New Injectors in Tehran, Iran

BACKGROUND

Global estimates suggest there are 15.6 million people who inject drugs (PWID) of whom 17.8% are living with HIV.Few studies have characterized newly-onset injectors with long-term injectors and its association with injecting risk behaviors.

OBJECTIVES

We examined the relationship between length of injection and risk behaviors among people who inject drugs (PWID) in Tehran, Iran.

METHODS

A cross-sectional study was conducted among PWID, from March to August 2016 in Tehran, Iran. PWID were recruited by convenience and snowball sampling from five Drop-in Centers (DIC) located in the south of Tehran. Our primary independent variable was length of injecting career, defined as the number of months since injecting initiation. Those defined as new injectors (were injecting for less than 18 months), and long-term injectors (as injecting drugs for more than 18 months). We reported the adjusted odds ratio (aOR) point estimate and 95% confidence interval (CI95%) as the effect measure. The level of significance used in multiple logistic regression model was 0.05. We used STATA v. 11 for all analyzes.

RESULTS

The analytical sample comprised of 500 participants (100% male). Mean (±SD) age of PWID with a length of injection history was 31.2 ± 7.2 years. Overall, 270 (54%) (CI95%: 49.6%, 58.4%) of participants were long-term injectors. The average age of drug use initiation among long-term injectors group was lower as compared to new injectors group (31.2 vs. 29.4, p < 0.001). The odds of distributive syringe sharing among new injectors were two times higher than long-term injectors (AOR = 2.1, 95% CI 1.4-4.7). The odds of receptive syringe sharing were lower among new injectors group (AOR = 0.7, CI95% 0.2-0.87), compared to long-term injectors. New injectors had higher odds of reusing their own syringes (OR = 2.8, 95% CI: 1.4-5.7; p = 0.01).

CONCLUSIONS

Improvements in harm reduction service provision can occur through taregted risk reduction education for new injectors focusing on reducing distributive syringe sharing among them.

Decreased Odds of Injection Risk Behavior Associated With Direct Versus Indirect Use of Syringe Exchange: Evidence From Two California Cities

BACKGROUND

While there is substantial evidence that syringe exchange programs (SEPs) are effective in preventing HIV among people who inject drugs (PWID), nearly all the evidence comes from PWID who obtain syringes from an SEP directly. Much less is known about the benefits of secondary exchange to PWID who get syringes indirectly from friends or acquaintances who visit an SEP for them.

OBJECTIVES

We evaluated the effectiveness of direct versus indirect syringe exchange in reducing HIV-related high-risk injecting behavior among PWID in two separate studies conducted in Sacramento and San Jose, California, cities with quite different syringe exchange models.

METHODS

In both studies associations between direct and indirect syringe exchange and self-reported risk behavior were examined with multivariable logistic regression models. Study 1 assessed effects of a "satellite" home-delivery syringe exchange in Sacramento, while Study 2 evaluated a conventional fixed-site exchange in San Jose.

RESULTS

Multivariable analyses revealed 95% and 69% reductions, respectively, in high-risk injection associated with direct use of the SEPs in Sacramento and San Jose, and a 46% reduction associated with indirect use of the SEP in Sacramento. Conclusions/Importance: The very large effect of direct SEP use in Sacramento was likely due in part to home delivery of sterile syringes. While more modest effects were associated with indirect use, such use nevertheless is valuable in reducing the risk of HIV transmission of PWID who are unable or unwilling to visit a syringe exchange.

The Health Benefits of Secondary Syringe Exchange

From a process evaluation, participants in San Francisco's syringe exchange program (SEP) are described. Three groups, primary, secondary, and nonexchangers, were interviewed for a total of 244 study participants recruited from eight needle exchange sessions. Fifty percent of all primary exchangers exchanged for one or more injecting drug user(s) (IDUs). Three general routes of syringe distribution were identified between primary and secondary exchangers: between close friends and lovers; for people who lived in close proximity to them; and with customers who bought drugs from them. Focusing on why some go to SEPs and why some rely on others to go for them, findings are summarized primarily as the barriers for not attending SEPs, including exposure, legal status, illness, drug lifestyle, and conflicts with service provision. The secondary exchangers had similar risk reduction profiles to the SEP users that overall were better than the nonexchangers. For example, they shared syringes and cookers significantly fewer times than nonexchangers. The results demonstrate that these client-provided exchanges enable the SEP to overcome injection drug users' obstacles to program attendance, thereby reaching even hard to access members of IDU populations. We found the effects of these client-provided services to be positive for the larger IDU population.

Factors Associated with HIV Seroprevalence among Participants Enrolling at a Needle Exchange Program

The purpose of this study was to identify HIV risk factors associated with participants who were HIV seropositive at Needle Exchange Program (NEP) entry. A sample of injection drug users (IDUs) who enrolled in an NEP between 1994–1997 were recruited into a prospective study and tested for HIV antibodies. Demographic and recent drug use characteristics were collected. Logistic regression models were constructed to identify factors associated with HIV-seropositive status at NEP entry. Of 811 evaluation participants, 87% were African American, 67% were male, and 30% were HIV seropositive. The multivariate model indicated that daily cocaine injection (Adjusted OR (AOR)=1.98), daily speedball injection (AOR=2.36), daily heroin injection (AOR=0.55), cohabitation with someone (AOR=0.7), and employment (AOR=0.4) were all significantly associated with HIV seroprevalence at NEP entry (p<0.05). These findings indicate that HIV-seropositive individuals entering NEP practice particularly risky behaviors and are more likely to need help in order to minimize the harm of drugs and HIV infection than their HIV-seronegative counterparts.

An inconvenient dataset: bias and inappropriate inference with the multilevel model

The multilevel model has become a staple of social research. I textually and formally explicate sample design features that, I contend, are required for unbiased estimation of macro-level multilevel model parameters and the use of tools for statistical inference, such as standard errors. After detailing the limited and conflicting guidance on sample design in the multilevel model didactic literature, illustrative nationally-representative datasets and published examples that violate the posited requirements are identified. Because the didactic literature is either silent on sample design requirements or in disagreement with the constraints posited here, two Monte Carlo simulations are conducted to clarify the issues. The results indicate that bias follows use of samples that fail to satisfy the requirements outlined; notably, the bias is poorly-behaved, such that estimates provide neither upper nor lower bounds for the population parameter. Further, hypothesis tests are unjustified. Thus, published multilevel model analyses using many workhorse datasets, including NELS, AdHealth, NLSY, GSS, PSID, and SIPP, often unwittingly convey substantive results and theoretical conclusions that lack foundation. Future research using the multilevel model should be limited to cases that satisfy the sample requirements described.

Syringe access, syringe sharing, and police encounters among people who inject drugs in New York City: a community-level perspective

BACKGROUND

Injection drug user (IDU) experience and perceptions of police practices may alter syringe exchange program (SEP) use or influence risky behaviour. Previously, no community-level data had been collected to identify the prevalence or correlates of police encounters reported by IDUs in the United States.

METHODS

New York City IDUs recruited through respondent-driven sampling were asked about past-year police encounters and risk behaviours, as part of the National HIV Behavioural Surveillance study. Data were analysed using multiple logistic regression.

RESULTS

A majority (52%) of respondents (n=514) reported being stopped by police officers; 10% reported syringe confiscation. In multivariate modelling, IDUs reporting police stops were less likely to use SEPs consistently (adjusted odds ratio [AOR]=0.59; 95% confidence interval [CI]=0.40-0.89), and IDUs who had syringes confiscated may have been more likely to share syringes (AOR=1.76; 95% CI=0.90-3.44), though the finding did not reach statistical significance.

CONCLUSIONS

Findings suggest that police encounters may influence consistent SEP use. The frequency of IDU-police encounters highlights the importance of including contextual and structural measures in infectious disease risk surveillance, and the need to develop approaches harmonizing structural policing and public health.

Factors associated with uptake, adherence, and efficacy of hepatitis C treatment in people who inject drugs: a literature review

INTRODUCTION AND METHODS

Hepatitis C virus (HCV) infections are highly prevalent amongst people who inject drugs (PWID). Despite well documented evidence of its effectiveness, suggested cost-effectiveness, and potential to reduce HCV prevalence rates, the uptake of antiviral HCV treatment by PWID is low. This nonsystematic literature review describes factors associated with the uptake, adherence, and efficacy of HCV treatment among PWID and discusses strategies to increase their uptake of treatment.

RESULTS

Low HCV treatment uptake among PWID is associated with a number of patient-related and provider-related barriers. Beliefs and fears about low efficacy and adverse effects on the patient's part are common. A substantial number of factors are associated with the chaotic lifestyle and altered social functioning of PWID, which are often associated with decompensation or relapsing into drug addiction. This may lead to perceived low adherence with treatment and low efficacy on the provider's part too, where lack of support, inadequate management of addiction, and other drug-related problems and poor treatment of side effects have been described. Practical issues such as the accessibility of treatment and finances also play a role. Strategies to improve the HCV treatment rate among PWID involve pretreatment management and assessment, a multidisciplinary approach, management of side effects, and enhanced education and counseling.

CONCLUSION

Specific factors are associated with poorer treatment outcomes in PWID on the side of both the patient and the treatment system. However, given that PWID can achieve treatment adherence and sustained virologic response rates comparable with those in nondrug users, drug use per se should not be considered a criterion for exclusion from treatment. Further development of measures leading to higher uptake of treatment and adherence in PWID and appropriate adaptation of HCV treatment guidelines represent important tools in this regard.

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.

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.

Change in HIV-HCV risk-taking behavior and seroprevalence among opiate users seeking treatment over an 11-year period and harm reduction policy

Our purpose was to assess change in HIV and HCV prevalence and risk-taking behaviors among IDUs over a period of time that included changes in French Public Health policy. Risk behavior and biological testing for serostatus were collected from cross-sectional samples of yearly new requests for opiate dependence treatment in Aquitaine, France between 1994 and 2004 (n = 648). Coincident declines in injection equipment sharing and HIV prevalence among injectors were observed, while sexual behavior remained stable. There was a decline in HCV prevalence that was not significant among injectors. After controlling for potential confounding variables, participants enrolled after 1995 were less likely to share injection material and those enrolled after 1999 were less likely to share spoons. Our findings give evidence for behavioral and seroprevalence changes among IDUs over a period of time that included changes in needle access policy.

Overview of HIV among injection drug users in New York City: critical next steps to eliminate racial/ethnic disparities

At the start of the HIV epidemic, 50% of new infections were among injection drug users (IDUs) in New York City. While HIV has declined among IDUs since the mid-1990s, parenteral transmission continues to overburden Blacks/Hispanic IDUs. Individual risk behaviors do not explain the distribution of HIV/AIDS among IDUs. Social and/or structural factors are likely fueling racial disparities creating a high-risk socioenvironmental context. While increased access to structural interventions (i.e., syringe exchange and pharmacy syringe access) is needed, it may not be sufficient to eliminate HIV/AIDS disparities among IDUs. Research on incorporating structural factors into intervention strategies is needed.

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.

The bottom-up approach to integrative validity: a new perspective for program evaluation

The Campbellian validity model and the traditional top-down approach to validity have had a profound influence on research and evaluation. That model includes the concepts of internal and external validity and within that model, the preeminence of internal validity as demonstrated in the top-down approach. Evaluators and researchers have, however, increasingly recognized that in an evaluation, the over-emphasis on internal validity reduces that evaluation's usefulness and contributes to the gulf between academic and practical communities regarding interventions. This article examines the limitations of the Campbellian validity model and the top-down approach and provides a comprehensive, alternative model, known as the integrative validity model for program evaluation. The integrative validity model includes the concept of viable validity, which is predicated on a bottom-up approach to validity. This approach better reflects stakeholders' evaluation views and concerns, makes external validity workable, and becomes therefore a preferable alternative for evaluation of health promotion/social betterment programs. The integrative validity model and the bottom-up approach enable evaluators to meet scientific and practical requirements, facilitate in advancing external validity, and gain a new perspective on methods. The new perspective also furnishes a balanced view of credible evidence, and offers an alternative perspective for funding.

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Molecular epidemiology of HIV-1 subtype B, CRF01_AE, and CRF07_BC infection among injection drug users in Taiwan

OBJECTIVE

An explosive outbreak of HIV-1 circulating recombinant form (CRF) 07_BC among injection drug users (IDUs) in Taiwan was first reported in 2004 and reach the peak in 2005. The objectives of this study were to investigate the molecular epidemiology of different HIV-1 subtypes and their associated risk factors among Taiwanese IDUs in 2004 and 2005.

METHODS

Questionnaires and blood specimens were collected from inmates from 4 detention centers and 2 prisons. HIV-1 subtypes were determined using nested polymerase chain reactions with multiplex primers and phylogenetic analyses. A case-control study was conducted to elucidate risk factors associated with CRF07_BC infection.

RESULTS

A total of 93.8%, 4%, and 2.2% of 451 inmates with IDU history were infected with CRF07_BC, subtype B, and CRF01_AE, respectively. Besides CRF07_BC, a new outbreak of CRF01_AE infection was identified among IDUs from central region. Multivariate analysis showed that sharing dissolved heroine solution [odds ratio (OR) = 17.2], sharing syringes (OR = 34), number of persons sharing syringes (2 vs. 1, OR = 3.1), and lower educational level (OR = 2.3) were risk factors associated with CRF07_BC infection.

CONCLUSIONS

Sharing dissolved heroine solution is a neglected risk factor associated with HIV-1 infection and it should be emphasized in the AIDS education and harm reduction programs immediately.

The syringe gap: an assessment of sterile syringe need and acquisition among syringe exchange program participants in New York City

BACKGROUND

Programmatic data from New York City syringe exchange programs suggest that many clients visit the programs infrequently and take few syringes per transaction, while separate survey data from individuals using these programs indicate that frequent injecting - at least daily - is common. Together, these data suggest a possible "syringe gap" between the number of injections performed by users and the number of syringes they are receiving from programs for those injections.

METHODS

We surveyed a convenience sample of 478 injecting drug users in New York City at syringe exchange programs to determine whether program syringe coverage was adequate to support safer injecting practices in this group.

RESULTS

Respondents reported injecting a median of 60 times per month, visiting the syringe exchange program a median of 4 times per month, and obtaining a median of 10 syringes per transaction; more than one in four reported reusing syringes. Fifty-four percent of participants reported receiving fewer syringes than their number of injections per month. Receiving an inadequate number of syringes was more frequently reported by younger and homeless injectors, and by those who reported public injecting in the past month.

CONCLUSION

To improve syringe coverage and reduce syringe sharing, programs should target younger and homeless drug users, adopt non-restrictive syringe uptake policies, and establish better relationships with law enforcement and homeless services. The potential for safe injecting facilities should be explored, to address the prevalence of public injecting and resolve the 'syringe gap' for injecting drug users.

Perceived risk, peer influences, and injection partner type predict receptive syringe sharing among young adult injection drug users in five U.S. cities

OBJECTIVES

This study examined risk factors for receptive syringe sharing (RSS) during illicit drug injection by persons 15-30 years old in five U.S. cities.

METHODS

Participants were recruited through street outreach and respondent-driven referrals in Baltimore, Chicago, Los Angeles, New York, and Seattle between May 2002 and January 2004. Surveys of drug use, sexual behaviors, and correlates were administered through audio computer-assisted self-interviews at baseline and, for the subset of participants who enrolled in an HIV/HCV prevention intervention trial, at 3-months and 6-months post-baseline. The proportions of injections involving RSS at baseline and at follow-up were used as outcomes in multivariate models that adjusted for intervention effects.

RESULTS

At baseline, 54% of 3128 participants reported RSS in the past 3 months. RSS decreased to 21% at 6-months post-baseline for the combined trial arms. Participants were more likely to report RSS if they perceived that their peers were not against RSS and if they injected with sex partners. Lower levels of perceived risk of infection with HIV (baseline, p<.001) or HCV (follow-up, p<.001) through RSS were also significant predictors of greater RSS.

CONCLUSIONS

Perceived risks, peer influences, and type of injection partner were robust predictors of RSS. Perceived risks and peer influences are particularly amenable to intervention efforts that may prevent RSS in this age group.

Needle Exchange and Injection-Related Risk Behaviors in Chicago

OBJECTIVE

To examine whether needle exchange program (NEP) use by injecting drug users (IDUs) affects injection risk behaviors over time.

METHODS

Between 1997 and 2000, 901 IDUs in Chicago were recruited for a cohort study from a multisite NEP and an area with no NEP. Participants were interviewed and tested for HIV at baseline and 3 annual follow-ups. Non-NEP users received HIV prevention services consistent with the Indigenous Leader Outreach Model. Random-effect logistic models were used to compare 5 injection-related risk behaviors between NEP users and nonusers.

RESULTS

The 30-day prevalence of receptive needle sharing decreased from 27.6% at baseline to 10.0% at visit 4 in NEP users and from 47.1% to 20.0% in nonusers. Similar patterns were observed for lending used needles, and NEP users were less likely to reuse their own needles. In multivariate analyses, NEP use was significantly associated with reduced odds of greater than 60% for receptive needle sharing, 45% for lending used needles, and 30% for sharing other injection paraphernalia as well as approximately a 2-fold increase in the odds of always bleaching used needles.

CONCLUSIONS

NEP use facilitates long-term reductions in injection risk practices, and the reductions are in addition to the effects of a behavioral intervention alone.

Experiences with and attitudes toward death and dying among homeless persons

BACKGROUND

Homeless persons face many barriers to health care, have few resources, and experience high death rates. They live lives of disenfranchisement and neglect. Few studies have explored their experiences and attitudes toward death and dying. Unfortunately, studies done in other populations may not apply to homeless persons. Exploring these experiences and attitudes may provide insight into life, health care, and end-of-life (EOL) concerns of this population.

OBJECTIVE

To explore the experiences and attitudes toward death and dying among homeless persons.

DESIGN

Qualitative study utilizing focus groups.

PARTICIPANTS

Fifty-three homeless persons recruited from homeless service agencies.

MEASUREMENTS

In-depth interviews, which were audiotaped and transcribed.

RESULTS

We present seven themes, some of which are previously unreported. Homeless persons described many significant experiences with death and dying, and many participants suffered losses while very young. These encounters influenced participants' attitudes toward risks and risky behavior: e.g., for some, these experiences provided justification for high-risk behaviors and influenced their behaviors while living on the streets. For others, they may be associated with their homelessness. Finally, these experiences informed their attitudes toward death and dying as well as EOL care; homeless persons believe that care will be poor at the EOL.

CONCLUSIONS

Findings from this study have implications for addressing social services, health promotion, prevention, and EOL care for homeless persons, as well as for others who are poor and disenfranchised.

Public citizens, marginalized communities: the struggle for syringe exchange in Springfield, Massachusetts

Syringe exchange programs, which, in order to prevent HIV infections, provide injection drug users with sterile syringes in exchange for used ones, operate at the intersection of conflicting social and political beliefs about disease, drugs, the common good, and the law. This paper describes community opposition that emerged from diverse quarters in response to a proposed syringe exchange program (SEP) in Springfield, Massachusetts. White suburban residents and inner-city African-Americans both drew on concepts of personal responsibility and self-sufficiency as they described their opposition to SEP. Through archival research and in-depth interviews with key community figures, I show how their similar political positions resulted from highly divergent views on the role of government in caring for citizens and communities. These arguments about addiction, HIV, and community both index and turn on the unique relationships with government experienced by a range of social actors.

Overcoming barriers to prevention, care, and treatment of hepatitis C in illicit drug users

Injection drug use accounts for most of the incident infections with hepatitis C virus (HCV) in the United States and other developed countries. HCV infection is a complex and challenging medical condition in injection drug users (IDUs). Elements of care for hepatitis C in illicit drug users include prevention counseling and education; screening for transmission risk behavior; testing for HCV and human immunodeficiency virus infection; vaccination against hepatitis A and B viruses; evaluation for comorbidities; coordination of substance-abuse treatment services, psychiatric care, and social support; evaluation of liver disease; and interferon-based treatment for HCV infection. Caring for patients who use illicit drugs presents challenges to the health-care team that require patience, experience, and an understanding of the dynamics of substance use and addiction. Nonetheless, programs are successfully integrating hepatitis C care for IDUs into health-care settings, including primary care, methadone treatment and other substance-abuse treatment programs, infectious disease clinics, and clinics in correctional facilities.

Evidence for a substantial role of sharing of injecting paraphernalia other than syringes/needles to the spread of hepatitis C among injecting drug users

In industrialized countries, transmission of hepatitis C occurs primarily through injecting drug use. Transmission of hepatitis C in injecting drug users is mainly associated with the sharing of contaminated syringes/needles, although evidence for risk of hepatitis C infection through sharing of other injecting paraphernalia is increasing. In this paper, the independent effects of sharing paraphernalia other than syringes/needles have been estimated. The prevalence and force of infection were modelled using three serological data sets from drug users in three centres in Belgium as a function of the sharing behaviour. It was found that sharing of materials other than syringes/needles indeed seemed to contribute substantially to the spread of hepatitis C among injecting drug users.

Efficient allocation of resources to prevent HIV infection among injection drug users: the Prevention Point Philadelphia (PPP) needle exchange program

The objective of this study is to determine the allocation of resources within a multi-site needle exchange program (NEP) that achieves the largest possible reduction in new HIV infections at minimum cost. We present a model that relates the number of injection drug user (IDU) clients and the number of syringes exchanged per client to both the costs of the NEP and the expected reduction in HIV infections per unit time. We show that cost-effective allocation within a multi-site NEP requires that sites be located where the density of IDUs is highest, and that the number of syringes exchanged per client be equal across sites. We apply these optimal allocation rules to a specific multi-site needle exchange program, Prevention Point Philadelphia (PPP). This NEP, we find, needs to add 2 or 3 new sites in neighborhoods with the highest density of IDU AIDS cases, and to increase its total IDU client base by about 28%, from approximately 6400 to 8200 IDU clients. The case-study NEP also needs to increase its hours of operation at two existing sites, where the number of needles distributed per client is currently sub-optimal, by 50%. At the optimal allocation, the estimated cost per case of HIV averted would be dollar 2800 (range dollar 2300-dollar 4200). Such a favorable cost-effectiveness ratio derives primarily from PPP's low marginal costs per distributed needle.

Binge drug use independently predicts HIV seroconversion among injection drug users: implications for public health strategies

Several studies have highlighted risk factors that cause HIV vulnerability among injection drug users (IDUs); these studies in turn have prompted public health officials to take action to minimize these risks. We sought to evaluate the potential association between binge drug use and HIV seroconversion and, subsequently, risk factors associated with binge drug use among a cohort of IDUs. To do this, we performed analyses of (1) associations with HIV seroconversion and (2) associations with binge drug use among participants enrolled in the Vancouver Injection Drug Users Study (VIDUS), a prospective cohort of IDU. Because serial measures for each individual were available, we undertook a time-updated Cox regression analysis to detect associations with HIV incidence and variables potentially associated with binge drug use were evaluated by using generalized estimating equations (GEE). Overall, 1548 IDU were enrolled into the VIDUS cohort between May 1996 and May 2003. There were 1013 individuals who were HIV seronegative at enrollment and had at least one follow-up visit; 125 (12%) became HIV positive during the study period for a cumulative incidence rate of 14% at 64 months after enrollment. In the final multivariate model, binge drug use [Adjusted Hazards Ratio: 1.61 (CI: 1.12, 2.31)] was independently associated with HIV seroconversion. In subanalyses, when we evaluated associations with binge drug use in GEE analyses, borrowing [Odds Ratio (OR): 153 (CI: 1.33-1.76)] and lending [OR: 1.73 (CI: 1.50-1.98)] syringes, sex trade work [OR: 1.14 (CI: 1.01-1.29)], frequent cocaine [OR: 2.34 (CI: 2.11-2.60)] and heroin [OR: 1.29 (CI: 1.17-1.43)] injection were independently associated with binge drug use and methadone [OR: 0.80 (CI: 0.71-0.89)] was protective against binge drug use. Our study identified an independent association between binge drug use and HIV incidence and demonstrated several high-risk drug practices associated with bingeing. Given the unaddressed public health risks associated with bingeing, a public health response protocol must be developed to minimize the personal and public health risks associated with the binge use of drugs.

Do needle syringe programs reduce HIV infection among injecting drug users: a comprehensive review of the international evidence

This first international review of the evidence that needle syringe programs reduce HIV infection among injecting drug users found that conservative interpretation of the published data fulfills six of the nine Bradford Hill criteria (strength of association, replication of findings, temporal sequence, biological plausibility, coherence of evidence, and reasoning by analogy) and all six additional criteria (cost-effectiveness, absence of negative consequences, feasibility of implementation, expansion and coverage, unanticipated benefits, and application to special populations). The Bradford Hill criteria are often used to evaluate public health interventions. The principal finding of this review was that there is compelling evidence of effectiveness, safety, and cost-effectiveness, consistent with seven previous reviews conducted by or on behalf of U.S. government agencies. Authorities in countries affected or threatened by HIV infection among injecting drug users should carefully consider this convincing evidence now available for needle syringe programs with a view to establishing or expanding needle syringe programs to scale.

Harm reduction interventions, behaviours and associated health outcomes in France, 1996-2003

AIMS

To track the effect of the French harm reduction programme targeted at intravenous drug users (IDUs) and associated health outcomes.

MATERIAL

Since 1996, we have collected monthly sales of sterile syringes and substitution treatments (buprenorphine high dosage and methadone) sold to IDUs in the 23 000 pharmacies in France and collated these figures in a single data base (SIAMOIS). To this data base we have also added the number of syringes distributed through community associations, as well as methadone treatments prescribed in public drug dependence clinics.

METHODS

For the period 1996-2003 we analysed syringe sales and prescribed substitution treatments as indicators of access to harm reduction services. We compared variations of these figures over time with trends in health outcome indicators [annual number of fatal overdoses, hepatitis C virus (HCV) and human immunodeficiency virus (HIV) prevalence among intravenous drug users], risk behaviour indicators (rate of syringe sharing or rate of syringe re-use) and legal indicators (heroin and cocaine use-related arrests).

FINDINGS

The number of sterile syringes sold or distributed to IDUs increased from 1996 to 1999 (+ 21%) and then decreased dramatically from 1999 to 2003 (-40%). In 2003, we estimated that more than 100,000 drug users used substitution treatments. Between 1996 and 2003, a decrease in syringe sharing and syringe re-use was observed, HIV prevalence among IDUs decreased from 40% to 20% and HCV prevalence remained high (60-70%). From 1996 to 2003, arrests due to heroin use declined (from 17 328 to 4025) and deaths due to overdoses also decreased (from 465 to 89), whereas arrests for cocaine use increased from 1184 to 2511.

CONCLUSION

Our results indicate that, since 1996 in France, IDUs have had greatly improved access to sterile syringes and substitution treatments. The decrease in syringe sharing and re-use practices and of HIV prevalence during the same time period indicates that the harm reduction policy implemented in France has had a positive impact. However, because of the persistent sharing and re-use of syringes and a remaining high HCV prevalence in IDUs, efforts to facilitate access to sterile syringes must continue, and targeting of at-risk groups must be improved. Behavioural surveys associated with HIV and HCV seroprevalence data are needed to further assess prevention of blood-borne infections among IDUs in France.

Requiring Help Injecting Independently Predicts Incident HIV Infection Among Injection Drug Users

BACKGROUND

Requiring help injecting has been associated with syringe sharing among injection drug users (IDUs). No prospective study has fully examined this risk factor and its relation to rates of HIV infection. We investigated whether requiring help injecting illicit drugs was a predictor of HIV infection among a prospective cohort of IDUs.

METHODS

The Vancouver Injection Drug User Study is a prospective study of more than 1500 IDUs who have been recruited from the Downtown Eastside of Vancouver since May 1996. At baseline and semiannually, subjects provided blood samples and completed an interviewer-administered questionnaire. The questionnaire elicits demographic data as well as information about drug use, HIV risk behavior, and drug treatment. HIV incidence rates were calculated using Kaplan-Meier methods, and Cox regression determined independent predictors of seroconversion.

RESULTS

A total of 1013 baseline HIV-negative participants were eligible for this study. Within this population, 418 (41.3%) participants had required help injecting during the last 6 months at baseline. Participants requiring help injecting were more likely to be female (odds ratio = 2.3, 95% confidence interval [CI]: 1.8-3.0; P < 0.001), were slightly younger (33.5 vs. 34.9 years of age; P = 0.014), and had fewer years of experience injecting drugs (7 vs. 11 years; P < or = 0.001). Among participants who required help injecting at baseline, cumulative HIV incidence at 36 months was 16.1% compared with 8.8% among participants who did not require help injecting (log-rank, P < 0.001). In an adjusted model controlling for potential confounding variables, being aboriginal (relative hazard [RH] = 1.68, 95% CI: 1.15-2.48), injecting cocaine daily (RH = 2.71, 95% CI: 1.87-3.95), and requiring help injecting (RH = 1.79, 95% CI: 1.23-2.62) remained independent predictors of HIV seroconversion.

CONCLUSIONS

These data demonstrate the need for interventions to reduce the risk of HIV infection among IDUs who require help injecting.

Injection risk behavior among women syringe exchangers in San Francisco

Women who inject drugs in cities where syringe exchange programs (SEPs) are well established may have different risks for HIV infection. In 1997, we interviewed 149 female syringe exchangers in San Francisco, CA, a city with high rates of injection drug use that is home to one of the largest and oldest SEPs in the United States. In this report, we describe their sociodemographics, health, and risk behavior, and we examine factors associated with recent syringe sharing. Fifty percent of respondents were women of color and the median age was 38 years. Most (86%) injected heroin and nearly half were currently homeless or had recently been incarcerated. One-third of all women reported needle sharing in the prior month. This was higher than the rate of needle sharing reported by a mixed gender sample of San Francisco exchangers in 1993, although it resembled the rate reported by a mixed gender sample in 1992. In a multivariate analysis, syringe sharing was associated with age, housing status, and sexual partnerships. Syringe sharers were more likely to be young, homeless, or have a sexual partner who was also an injection drug user. While wide access to sterile syringes is an important strategy to reduce HIV transmission among injection drug users (IDU), syringe exchange alone cannot eradicate risky injection by female IDU. Additional efforts to reduce risky injection practices should focus on younger and homeless female IDU, as well as address selective risk taking between sexual partners.

Changes in the sharing of drug injection equipment among street-recruited injection drug users in Chicago, Illinois, 1994--1996

This study examines changes in the multi-person use of drug injection paraphernalia during the mid-1990s, a time of increasing awareness of HIV transmission modes and availability of prevention programs. Beginning in 1994, 794 street-recruited injection drug users in Chicago were interviewed and followed at 6 and 12 months postbaseline. Random-effects, pattern-mixture logistic regression models were used to determine correlates of five injection-equipment sharing practices, while accounting for repeated measurement and study attrition. At baseline, 45.7% of participants reported receptive syringe sharing in the previous 6 months. Syringe-mediated sharing was reported by 28.7% of participants and the sharing of cookers (65.1%), cotton filters (55.7%), and rinse water (46.9%) was common. During follow-up, the proportion of all sharing behaviors decreased significantly, especially receptive syringe sharing. Participation in a syringe exchange program was associated with reductions in receptive syringe sharing and syringe-mediated sharing, but not the sharing of cookers.

[Harm reduction policy related to drug use: the needles exchange programs]

In several developed countries, needles exchange programs (NEPs) are a key preventive tool in harm reduction policy related to drug use. Many studies about NEP show it reduces HIV infections related to syringes sharing when part of others preventive actions. NEPs seem to have no impact on HCV transmission. Furthermore, young drug users, who are at high risk for HIV and HCV infections, are not attending NEPs very often. Trying to maintain high accessibility to sterile syringes, efforts must be stressed on hard-to-reach populations such as young injection drug users (IDU), focusing on their social network. Emphasis must also be put on prevention of unsafe sexual intercourse, often related to syringe sharing, which must be more prevented. Finally, design of assessment studies should be improved.

Sexual relationships, secondary syringe exchange, and gender differences in HIV risk among drug injectors

Injection drug use continues to place women at risk for human immunodeficiency virus (HIV) through both risky injecting practices and risky sexual behavior with male injection drug users (IDUs). Although attendance at syringe-exchange programs (SEPs) is protective against HIV, a recent study found that women attending SEPs who exchanged syringes for other people (secondary exchange) were at greater risk for HIV seroconversion, potentially through risky sexual behavior. We examined this question in a sample of 531 IDUs (175 women and 356 men) attending 23 SEPs in California in 2001. Findings indicated that women were more likely than men to engage in secondary exchange and were more likely to have IDU sexual partners. In multivariate analysis among women, secondary exchange was independently associated with distributive syringe sharing, not engaging in receptive sharing, and not exchanging sex for money or drugs. Multivariate analysis among men found that having an IDU sexual partner was associated with secondary exchange. Women's sexual risk behavior was not associated with secondary exchange, and although women's secondary exchange was associated with individual protection for injection-related behaviors, it may increase network risk. More information on network members is needed to understand gender differences in secondary exchange.

Addressing the "risk environment" for injection drug users: the mysterious case of the missing cop

Ecological models of the determinants of health and the consequent importance of structural interventions have been widely accepted, but using these models in research and practice has been challenging. Examining the role of criminal law enforcement in the "risk environment" of injection drug users (IDUs) provides an opportunity to apply structural thinking to the health problems associated with drug use. This article reviews international evidence that laws and law enforcement practices influence IDU risk. It argues that more research is needed at four levels--laws; management of law enforcement agencies; knowledge, attitudes, beliefs, and practices of frontline officers; and attitudes and experiences of IDUs--and that such research can be the basis of interventions within law enforcement to enhance IDU health.

Neighborhood differences in patterns of syringe access, use, and discard among injection drug users: implications for HIV outreach and prevention education

The article presents results from the Syringe Access, Use, and Discard: Context in AIDS Risk research project comparing two neighborhoods by (1) socioeconomic and demographic characteristics; (2) patterns of syringe access, use, and discard; and (3) encounters with a local human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) outreach project targeted to injection drug users (IDUs). The results show that IDUs in more economically advantaged neighborhoods were more likely to acquire syringes from a single source (rather than multiple sources), more likely to inject alone in their own residence (rather than public injection locales), and more likely to dispose of syringes in private garbage cans rather alleys or dumpsters. These results are further associated with the likelihood of encountering street outreach workers, with IDUs in more affluent neighborhoods much less likely to have any such contacts. Based on the different patterns of access, use, and discard evident in each neighborhood, the results indicate that different and more carefully tailored local outreach and prevention strategies are urgently needed.

Towards more effective public health programming for injection drug users: development and evaluation of the injection drug user quality of life scale

The psychometric properties of the Injection Drug User Quality of Life Scale (IDUQOL) were assessed in 61 Montreal IDUs in 2001, 85% of whom were reinterviewed within four weeks. The reliability of the IDUQOL was acceptable (ICC = 0.71) and concordance between the IDUQOL and the Flanagan Quality of Life Scale was moderate (Pearson coefficient = 0.57). Quality of life was negatively associated with injection cocaine and emergency department use with both instruments; these results were more striking for the IDUQOL. The IDUQOL is a culturally relevant quality of life instrument with good psychometric properties. The IDUQOL may be useful in the development and evaluation of interventions for IDUs.

Secondary syringe exchange among injection drug users

Syringe-exchange programs (SEPs) have proven to prevent the spread of bloodborne pathogens, primarily human immunodeficiency virus (HIV), among injection drug users (IDUs). In the United States, only about 7% of IDUs have access to and use SEPs. Some IDUs engage in secondary syringe exchange (SSE), meaning that one IDU (a "provider") obtains syringes at an SEP to distribute to other IDUs ("recipients"). This formative qualitative research was conducted to understand why and how IDUs engage in SSE to aid in the development of a large-scale peer HIV prevention intervention. Interviews with 47 IDUs in Oakland and Richmond, California, indicated that SSE was embedded in existing social networks, which provided natural opportunities for peer education. SSE providers reported a desire to help other IDUs as their primary motivation, while recipients reported convenience as their primary reason for using SSE. Building SSE into SEP structures can facilitate an effective provision of risk reduction supplies and information to IDUs who do not access SEPs directly.

Prevention and treatment of hepatitis C in injection drug users

Injection drug users constitute the largest group of persons infected with the hepatitis C virus (HCV) in the United States, and most new infections occur in drug users. Controlling hepatitis C in the U.S. population, therefore, will require developing, testing, and implementing effective prevention and treatment strategies for persons who inject drugs. Fortunately, a substantial body of research and clinical experience exists on the prevention and management of chronic viral diseases among injection drug users. The need to implement interventions to stop the spread of HCV among drug users is critical. The capacity of substance-use treatment programs need to be expanded to accommodate all who want and need treatment. Physicians and pharmacists should be educated in how to provide access to sterile syringes and to teach safe injection techniques, both of which are lifesaving interventions. The treatment of hepatitis C in drug users requires an interdisciplinary approach that brings together expertise in treating hepatitis and caring for drug users. Treatment decisions should be made individually by patients with their physicians, based on a balanced assessment of risks and benefits and the patient's personal values. Physicians should carefully assess, monitor, and support adherence and mental health in all patients, regardless of whether drug use is known or suspected. Research is needed to better understand how best to prevent and treat hepatitis C in substance users. In the meantime, substantial progress can be made if existing knowledge and resources are brought to bear.

Prevention and treatment of hepatitis C in injection drug users

Injection drug users constitute the largest group of persons infected with the hepatitis C virus (HCV) in the United States, and most new infections occur in drug users. Controlling hepatitis C in the U.S. population, therefore, will require developing, testing, and implementing effective prevention and treatment strategies for persons who inject drugs. Fortunately, a substantial body of research and clinical experience exists on the prevention and management of chronic viral diseases among injection drug users. The need to implement interventions to stop the spread of HCV among drug users is critical. The capacity of substance-use treatment programs need to be expanded to accommodate all who want and need treatment. Physicians and pharmacists should be educated in how to provide access to sterile syringes and to teach safe injection techniques, both of which are lifesaving interventions. The treatment of hepatitis C in drug users requires an interdisciplinary approach that brings together expertise in treating hepatitis and caring for drug users. Treatment decisions should be made individually by patients with their physicians, based on a balanced assessment of risks and benefits and the patient's personal values. Physicians should carefully assess, monitor, and support adherence and mental health in all patients, regardless of whether drug use is known or suspected. Research is needed to better understand how best to prevent and treat hepatitis C in substance users. In the meantime, substantial progress can be made if existing knowledge and resources are brought to bear.

Hepatitis-associated knowledge is low and risks are high among HIV-aware injection drug users in three US cities

AIMS

Injection drug use is a major risk factor for HIV and hepatitis infections. Whereas programs to prevent new infections have focused on HIV, they have generally neglected hepatitis B and C. This study was designed to examine the interrelationships among HIV and hepatitis knowledge, risky drug preparation and injection practices, and participation in syringe exchange programs (SEPs).

DESIGN

Surveys of injection drug users (IDUs) collected data on socio-demographics, medical history, drug use and injection practices, and HIV- and hepatitis-related knowledge.

SETTING

Inner-city US neighborhoods in Chicago, IL, Hartford, CT and Oakland, CA.

PARTICIPANTS

The study population was a convenience sample of 493 IDUs recruited using street outreach and snowball sampling strategies.

MEASUREMENTS

HIV and hepatitis knowledge, injection-related risks for virus transmission, associations between the two, and with SEP use.

FINDINGS

HIV knowledge was significantly higher than hepatitis knowledge among SEP customers and non-customers alike. Elevated hepatitis knowledge was associated with a history of substance abuse treatment, hepatitis infection, hepatitis B vaccination and injection practices that reduced contact with contaminated blood or water but not with SEP use. SEP customers were consistently less likely to engage in risk behaviors, with the notable exception of safely staunching blood postinjection.

CONCLUSION

Increased hepatitis awareness among IDUs is necessary for reducing hepatitis transmissions. Although SEPs continue to effectively disseminate HIV prevention messages-as evidenced by lowered risk behaviors among their customers-they must do more to prevent hepatitis transmissions.

Two- to sixfold decreased odds of HIV risk behavior associated with use of syringe exchange

We report results of a community study of syringe exchange that compared the HIV risk behavior of exchange clients with that of nonclients. A prospective cohort of 259 untreated injecting drug users (IDUs) was followed a mean of 10.7 months after baseline. In assessing whether HIV risk behavior at follow-up was associated with study participants' follow-up use of the exchange, we controlled their baseline risk behavior and exchange use as markers of risk-taking tendency in addition to other potential confounders. We also examined whether there was a differential benefit of exchange use for IDUs with versus those without access to other sources of syringes. Both univariate and multivariate analyses revealed a more than twofold decreased odds of HIV risk behavior associated with use of the exchange. In a second multivariate analysis, which examined the interaction of exchange use with access to other sources of syringes, the odds of HIV risk behavior were decreased more than sixfold for IDUs without other sources. We conclude that use of the exchange had a substantial protective effect against HIV risk behavior and may have been especially critical for IDUs without other sources of syringes.

Factors associated with persistent high-risk syringe sharing in the presence of an established needle exchange programme

Vancouver has experienced an explosive HIV epidemic despite the presence of a needle exchange programme (NEP). We sought possible explanations for high-risk syringe sharing among Vancouver injection drug users over the period January 1999 to October 2000. Overall, 14% of participants reported high-risk sharing. Although acquiring needles exclusively from the NEP was independently associated with less sharing, we identified several risk factors for persistent sharing, including difficulty accessing sterile needles, bingeing, and frequent cocaine injection.