High-risk Injection Drug Users Research Articles

MODELING AND DYNAMICS OF HIV TRANSMISSION AMONG HIGH-RISK GROUPS IN GUANGZHOU CITY, CHINA

In this paper, a multicompartmental model is formulated to study how HIV is transmitted among different HIV high-risk groups, including MSM (men who have sex with men), FRs (foreigner residents), FSWs (female sex workers), and IDUs (injection drug users). The explicit expression for the basic reproduction number is obtained via the next generation matrix approach. We show that the disease free equilibrium is locally as well as globally asymptotically stable (the disease goes to extinction) when the basic reproduction number is less than unity, and the disease is always present when the basic reproduction number is larger than unity. As an illustration of our theoretical results, we conduct numerical simulations. We also conduct a case study where model parameters are estimated from the demographic and epidemiological data from Guangzhou. Using the parameter estimates, we predict the HIV/AIDS trend for each high-risk group. Furthermore, our study suggests that reducing the transmission routes of the disease and increasing condom use will be useful for control of HIV transmission.

Impact of Mobility on Methicillin-Resistant Staphylococcus aureus among Injection Drug Users

In this study, we develop and present a deterministic model for the transmission dynamics of methicillin-resistant staphylococcus aureus (MRSA) among injection drug users. The model consists of non-injection drug users as well as low-and high-risk injection drug users (IDUs). The model further incorporates the movement of these individuals between large metro, suburban and rural areas. The model parameters were estimated by fitting the model to the 2008–2013 disease prevalence data for non-IDUs obtained from the Agency for Healthcare and Research and Quality (AHRQ), as well as the 2009–2013 Census Bureau data for the number of individuals migrating between three different counties in Kansas. Sensitivity analysis was implemented to determine the parameters with the most significant impact on the total number of infected individuals; the transmission probability, recovery rates, and positive behavioral change parameter for the subgroup have the most significant effect on the number of infected individuals. Furthermore, the sensitivity of the parameters in the different areas was the same when the areas are disconnected. When the areas are connected, the parameters in large-metro areas were the most sensitive, and the rural areas were least sensitive. The result shows that to effectively control the disease across the large metro, suburban and rural areas, it is best to focus on controlling both behavior and disease in the large metro area as this has a trickle-down effect to the other places. However, controlling behavior and disease at the same time in all the areas will lead to the elimination of the disease.

The Impact of Methadone Maintenance Treatment on HIV Risk Behaviors among High-Risk Injection Drug Users: A Systematic Review

Injection drug users (IDUs) are at high risk of acquiring HIV infection through preventable drug- and sex-related HIV risk behaviors. In recent decade, there has been a growing evidence that methadone maintenance treatment (MMT) is associated with a significant decrease in both drug- and sex-related risk behaviors among this high-risk population. The better understanding of the relationship between MMT and HIV-related risk behaviors will help to better inform future HIV prevention strategies, which may have policy implications as well. In this systematic review, we therefore aimed to explore the relevant literature to more clearly examine the possible impact of MMT on HIV risks behaviors among high-risk IDUs. The findings thus far suggest that MMT is associated with a significant decrease in injecting drug use and sharing of injecting equipment. Evidence on sex-related risk behavior is limited, but suggest that MMT is associated with a lower incidence of multiple sex partners and unprotected sex. The literature also suggests that the most significant factor in reducing HIV risks was treatment adherence. As such, more attention needs to be given in future studies to ensure the higher rates of access to MMT as well as to improve the adherence to MMT.

Transmission dynamics for Methicilin-resistant Staphalococous areus with injection drug user

BackgroundMethicillin-resistant Staphylococcus aureus (MRSA) is a bacterial pathogen resistance to antibiotics including methicillin. The resistance first emerged in 1960 in a healthcare setting only after two years of using methicillin as a viable treatment for methicillin-susceptible Staphylococcus aureus. MRSA leads to infections in different parts of the body including the skin, bloodstream, lungs, or the urinary tract.MethodsA deterministic model for methicillin-resistant Staphylococcus aureus (MRSA) with injection drug users is designed. The model incorporates transmission of MRSA among non-injection drug users and injection drug users (IDUs) who are both low-and high-risk users. A reduced MRSA transmission model with only non-IDUs is fitted to a 2008-2013 MRSA data from the Agency for Healthcare and Research and Quality (AHRQ). The parameter estimates obtained are projected onto the parameters for the low-and high-risk IDUs subgroups using risk factors obtained by constructing a risk assessment ethogram. Sensitivity analysis is carried out to determine parameters with the greatest impact on the reproduction number using the reduced non-IDUs model. Change in risk associated behaviors was studied using the full MRSA transmission model via the increase in risky behaviors and enrollment into rehabilitation programs or clean needle exchange programs. Three control effectiveness levels determined from the sensitivity analysis were used to study control of disease translation within the subgroups.ResultsThe sensitivity analysis indicates that the transmission probability and recovery rates within the subgroup have the highest impact on the reproduction number of the reduced non-IDU model. Change in risk associated behaviors from non-IDUs to low-and high-risk IDUs lead to more MRSA cases among the subgroups. However, when more IDUs enroll into rehabilitation programs or clean needle exchange programs, there was a reduction in the number of MRSA cases in the community. Furthermore, MRSA burden within the subgroups can effectively be curtailed in the community by implementing moderate- and high-effectiveness control strategies.ConclusionsMRSA burden can be curtailed among and within non-injection drug users and both low-and high-risk injection drug users by encouraging positive change in behaviors and by moderate- and high-effectiveness control strategies that effectively targets the transmission probability and recovery rates within the subgroups in the community.

The Significance of Harm Reduction as a Social and Health Care Intervention for Injecting Drug Users: An Exploratory Study of a Needle Exchange Program in Fresno, California

Infectious disease remains a significant social and health concern in the United States. Preventing more people from contracting HIV/AIDS or Hepatitis C (HCV), requires a complex understanding of the interconnection between the biomedical and social dimensions of infectious disease. Opiate addiction in the US has skyrocketed in recent years. Preventing more cases of HIV/AIDS and HCV will require dealing with the social determinants of health. Needle exchange programs (NEPs) are based on a harm reduction approach that seeks to minimize the risk of infection and damage to the user and community. This article presents an exploratory small-scale quantitative study of the injection drug using habits of a group of injection drug users (IDUs) at a needle exchange program in Fresno, California. Respondents reported significant decreases in high risk IDU behaviors, including sharing of needles and to a lesser extent re-using of needles. They also reported frequent use of clean paraphernalia. Greater collaboration between social and health outreach professionals at NEPs could provide important frontline assistance to people excluded from mainstream office-based services and enhance efforts to reduce HIV/AIDS or HCV infection.

HIV providers’ likelihood to prescribe pre-exposure prophylaxis (PrEP) for HIV prevention differs by patient type: a short report

ABSTRACTPre-exposure prophylaxis (PrEP), the antiretroviral treatment regimen for HIV-negative people at high risk of acquiring HIV, has demonstrated efficacy across clinical trials in several patient populations. The Centers for Disease Control (CDC) have released detailed guidelines to aid providers in prescribing PrEP for their high-risk patients, including men who have sex with men (MSM), high-risk heterosexuals, and injection drug users (IDUs). Given that much attention in PrEP has focused on MSM patients, the present study used an online survey to assess factors involved in HIV care providers’ (n = 363) decisions about prescribing PrEP, along with their willingness to prescribe PrEP to patients from various risk populations (e.g., MSM, heterosexuals, IDUs). The efficacy of PrEP was an important factor in providers' decisions about prescribing PrEP, as were considerations about patients’ adherence to the regimen, regular follow-up for care, and medication costs. This survey's findings also suggest that providers’ willingness to prescribe PrEP varies by patient group, with providers most willing to initiate the regimen with MSM who have an HIV-positive partner, and least willing to prescribe to high-risk heterosexuals or IDUs. In the context of the current CDC recommendations for PrEP that include MSM, heterosexuals, and IDUs, examining providers’ rationales for and barriers against supporting this HIV prevention strategy across patient groups merits further attention.

PTH-100 A comparative gene expression study between individuals with apparent resistance, spontaneous clearance, or chronic infection from hcv

<h3>Introduction</h3> We have identified a group of high risk injection drug users who share needles, syringes and other injecting paraphernalia over a long period of time yet who remain uninfected by hepatitis C virus (HCV). These individuals appear to be resistant to HCV infection and we have termed them exposed uninfected (EU). Defining factors that may prevent HCV infection in these cohorts could give valuable insight into the mechanisms of natural resistance to HCV. <h3>Method</h3> Individuals at high risk of recurrent exposure to HCV infection from long term IDU were recruited in Plymouth and if HCV antibody and HCV RNA negative were termed exposed uninfected (EU). We have compared the transcriptional profiles of intravenous drug users (IDU) with 3 different outcomes following HCV exposure – chronic hepatitis C infection (CHCV; n = 6), spontaneously resolution of HCV (SR; HCV Ab positive but HCV RNA negative, n = 6) and exposed but uninfected (EU; n = 6). Agilent single channel microarray was performed on RNA isolated from peripheral blood mononuclear cells and the results were analysed on Ingenuity Pathway Analysis software (Qiagen). The identified targets were subsequently validated at a protein level. <h3>Results</h3> 1465 genes between the EU and CHCV group, 4377 between the CHCV and SR group and 4510 between the SR and EU group were significantly up or down regulated. Of the differentially regulated genes, the association with resistance to HCV was strongest for IL27 and CXCL7 which were significantly upregulated in EU (IL27 log fold change EU vs SR: 1.943, p = 1.72E-04 and CXCL7 log fold change EU vs CHCV 2.359, p = 6.04E-03) relative to the other 2 groups. At a protein level, the median IL27 serum level in the EU group (n = 13), detected by sandwich ELISA, was significantly higher (p = 0.008) compared to CHCV (n = 14), healthy control (HC; n = 8) and SR (n = 14) groups. The CD28 mediated T-helper cell signalling pathway was significantly upregulated in SR (ratio 0.348, p = 2.77E-05) relative to the 2 other groups. <h3>Conclusion</h3> Significant differences in gene expression were found in injection drug users with different outcomes from exposure to HCV infection. EU and SR exhibit differences related to innate and adaptive immunity compared to CHCV that likely contribute to natural resistance and spontaneous clearance of HCV. <h3>Disclosure of interest</h3> None Declared.

The efficiency of targeted intervention in limiting the spread of HIV and Hepatitis C Virus among injecting drug users

Background. Interventions aimed at minimizing the spread of blood borne infections among Injecting Drug Users (IDU) are impeded by limitations in resources. To enhance their efficiency, it may be beneficial to target specific behavioural subpopulations, distinguished by syringe sharing tendencies.Methods. We used mathematical modelling to explore the effects of two types of intervention: removal of individuals from the injecting population and risk decrease at group-level (e.g. distribution of syringes). We computed the direct effects of intervention on the probability of obtaining and spreading infection as a function of baseline risk behaviour. Population level effects of (targeted) intervention were explored using a differential equations model, which incorporated two levels of risk.Results. Within most scenarios of risk distribution considered, HIV could be substantially reduced or eliminated by targeting high risk IDU only. Conversely, higher incidence reductions for HCV were reached in many scenarios when targeting low risk IDU. The potential for preventing infections by removal of uninfected IDU increases with baseline risk, but so does the probability that an IDU is already infected before being reached by intervention. Decreasing risk is likely to only delay rather than prevent infection for IDU borrowing many syringes, especially for a very infectious disease such as HCV.Conclusions. The efficiency of intervention on injecting drug users may be much enhanced by targeting specific risk subgroups. However, the optimal targeting policy depends strongly on the infection under consideration.

Decline in incidence of HIV and hepatitis C virus infection among injecting drug users in Amsterdam; evidence for harm reduction?

In Amsterdam, HIV prevalence has nearly halved among injecting drug users (IDU) since 1990. Hepatitis C virus (HCV) prevalence also declined; HIV and HCV incidence dropped to nearly zero. We examined possible explanations for these time trends, among which the implementation of harm reduction measures aimed at reducing the risk behaviour of IDU. We used individual-based modelling of the spread of HIV and HCV. Information about demographic parameters was obtained from the Amsterdam Cohort Study (ACS) among drug users. The model included changes in inflow of new IDU and death rates over time, the latter dependent on age and time since HIV seroconversion. We considered different scenarios of risk behaviour. IDU in Amsterdam. Simulated HIV and HCV incidence and prevalence were compared with ACS data. Assuming that harm reduction measures had led to a strong decrease in risk behaviour over time improved the model fit (squared residuals decreased by 30%). However, substantial incidence and HIV prevalence decline were already reproduced by incorporating demographic changes into the model. In particular, lowered disease spread might be a result of depletion of high-risk IDU among those at risk for disease, and a decrease in the number of high-risk individuals in the population due to HIV-related mortality. Marked decreases in HIV and HCV in Amsterdam since 1990 could be due partly to harm reduction measures; however, they may also be attributable largely to changes in the IDU population. Future research aimed at quantifying the benefits of interventions should not neglect the impact of natural epidemic progression and demographic changes.

Differences in HIV risk behavior of injection drug users in New York City by health care setting

The purpose of this study is to examine the HIV risk behaviors and demographic characteristics of injection drug users (IDUs) by type of health care setting, which can inform development of tailored structural interventions to increase access to HIV prevention and medical treatment services. IDU syringe customers were recruited from pharmacies as part of the “Pharmacist As Resources Making Links to Community Services” (PHARM-Link) study, a randomized community-based intervention in New York City (NYC) aimed at connecting IDUs to HIV prevention, medical, and social services. An ACASI survey ascertained demographics, risk behavior, health-care utilization, and location where health care services were received in the past year. Data were analyzed using logistic regression. Of 602 participants, 34% reported receiving health care at a community clinic, 46% a private medical office, 15% a mobile medical unit, and 59% an emergency room (ER). After adjustment, participants who attended a community clinic were significantly more likely to have health insurance, report syringe sharing, and be HIV positive. Whites, nondaily injectors, insured, and higher income IDUs were more likely to attend a private medical office. Participants who recently used a case manager and had multiple sexual partners were more likely to use a mobile medical unit. ER attendees were more likely to be homeless and report recent drug treatment use. These findings show that IDU demographics and risk behaviors differ by health care setting, suggesting that risk reduction interventions should be tailored to health care settings. Specifically, these data suggest that community clinics and mobile medical units serve high-risk IDUs, highlighting the need for more research to develop and test innovative prevention and care programs within these settings.

Characteristics and health service utilization in two samples of young injection drug users recruited using direct and referral methods in San Francisco, California.

Background: Targeted sampling (TS) and respondent-driven sampling (RDS) methods are methods used to recruit ‘hard-to-reach’ populations. We examine similarities and differences in population characteristics and health service utilization, in two independent samples of young adult injection drug users (IDU). Methods: Data from two samples of young adult (18-29 years) IDU sampled using RDS (N=31) and TS (N=97) in San Francisco, California were compared: (1) a cross-sectional study of IDU using RDS as part of the National HIV Behavioral Survey (NHBS) IDU-2 Study conducted by the San Francisco Department of Public Health, from May 2009 to December 2009; and (2) the UFO Study, an ongoing prospective study of young IDU that used TS methods to sample young IDU (<30 years) from May 2010 to December 2010. Results: Compared to the TS sample, the RDS sample was more heterogeneous demographically: a higher proportion of women, and racial/ethnic diversity; a significantly larger proportion of the RDS sample (vs. TS) previously received an HIV test (98.6% vs. 88.5%) whereas the TS sample had a significantly higher prevalence of HCV (58.7% vs. 15.1%). Conclusion: TS and RDS reached a similar cross section of the young adult IDU population in San Francisco; however, some notable differences were observed, especially in HCV infection prevalence. The findings highlight the need for continued efforts to improve sampling strategies aimed high risk IDU, so as to inform both public health surveillance, research and prevention interventions.

Peer-Education Intervention to Reduce Injection Risk Behaviors Benefits High-Risk Young Injection Drug Users: A Latent Transition Analysis of the CIDUS 3/DUIT Study

We analyzed data from a large randomized HIV/HCV prevention intervention trial with young injection drug users (IDUs) conducted in five U.S. cities. The trial compared a peer education intervention (PEI) with a time-matched, attention control group. Applying categorical latent variable analysis (mixture modeling) to baseline injection risk behavior data, we identified four distinct classes of injection-related HIV/HCV risk: low risk, non-syringe equipment-sharing, moderate-risk syringe-sharing, and high-risk syringe-sharing. The trial participation rate did not vary across classes. We conducted a latent transition analysis using trial baseline and 6-month follow-up data, to test the effect of the intervention on transitions to the low-risk class at follow-up. Adjusting for gender, age, and race/ethnicity, a significant intervention effect was found only for the high-risk class. Young IDU who exhibited high-risk behavior at baseline were 90 % more likely to be in the low-risk class at follow-up after the PEI intervention, compared to the control group.

Cytokine profiles in high risk injection drug users suggests innate as opposed to adaptive immunity in apparent resistance to hepatitis C virus infection

A cohort of injection drug users (IDU) have been identified who despite a long history of IDU and sharing of injecting equipment remain seronegative and aviraemic for hepatitis C virus (HCV). They have been termed HCV exposed uninfected (EU). The study of potential innate or adaptive immune mechanisms of resistance to HCV infection in this group is of interest. The aim of this study was to determine the levels of a broad range of cytokines in serum of exposed, uninfected individuals to ascertain whether there is a specific cytokine profile associated with apparent resistance to HCV. Sera from 22 EU individuals were analysed for a range of cytokines and chemokines, and compared to 16 treatment-naive chronic HCV cases (HCV Ab+ RNA+), 16 individuals with spontaneous resolution of HCV (HCV-Ab+ and HCV-RNA-) and 10 healthy unexposed controls. EU subjects had strikingly higher levels of both IL-6 (on average more than 100-fold, P = 0.001) and IL-8 (on average more than 10-fold, P < 0.001) than the comparison groups. Additionally higher levels of tumour necrosis factor-alpha (TNF-α; on average up to threefold, P = 0.02) were seen in EU individuals. The levels of interferon-alpha (IFN-α) were upregulated in all HCV exposed groups in comparison to healthy controls (P = 0.013). Adaptive immune cytokine levels were no different between the groups. Cytokine profiling demonstrated raised levels of pro-inflammatory innate immune cytokines and chemokines in EU IDU, in particular interleukin-6 and interleukin-8. These findings suggest innate immune activation may be the key to prevention of infection in this cohort.

Understanding the association between injecting and sexual risk behaviors of injecting drug users in Manipur and Nagaland, India

BackgroundIn India, as in rest of the world, HIV prevention programs have focused on HIV transmission through unsafe injecting practices with less attention on sexual risk behaviors among injecting drug users (IDUs). This study examines the sexual risk taking behaviors of IDUs associated with their pattern of drug use in India.MethodsData were obtained from the behavioral tracking survey conducted in 2009 among 1712 IDUs in two districts each of Manipur and Nagaland states in Northeastern part of India. Sexual risk behaviors among IDUs were assessed in terms of multiple sex partners, sex with a paid female partner in the last 12 months and inconsistent condom use with any female partner.ResultsMore than one-fourth (27%) in Manipur and almost one in two (47%) IDUs reported having had sex with two or more female partners in the past 12 months. In Manipur where heroin is commonly used, the odds of having multiple sex partners were higher among non-heroin users than heroin users (42% vs. 23%, Adjusted Odds Ratio (AOR): 1.7, 95% Confidence Interval (CI): 1.1-2.6) and who shared needles/syringes in the last one month than who did not share (46% vs. 26%, AOR: 2.2, CI: 1.2-4.0). In Nagaland, where Spasmoproxyvon (SP, a synthetic opioid analgesic that contains dextropropoxyphene, dicyclomine hydrochloride and paracetamol) is most common, regular injectors as compared to occasional injectors were more likely to report multiple sex partners (67% vs. 42%, AOR: 2.7, CI: 1.8-4.1) and sex with paid partners (13% vs. 3%, AOR: 6.0, CI: 3.0-12.1). Sharing of needles/syringes was positively associated with multiple sex partners (51% vs. 44%, AOR: 1.6, CI: 1.2-2.2), and inconsistent condom use (93% vs. 80%, AOR: 3.0, CI: 1.8-5.1).ConclusionsIDUs with unsafe injecting practices also engage in risky sexual practices magnifying the risk of HIV infection. There is a need to focus on prevention of sexual transmission among high-risk IDUs, particularly in areas where Spasmoproxyvon is commonly used.

The cost-effectiveness and population outcomes of expanded HIV screening and antiretroviral treatment in the United States.

Although recent guidelines call for expanded routine screening for HIV, resources for antiretroviral therapy (ART) are limited, and all eligible persons are not currently receiving treatment. To evaluate the effects on the U.S. HIV epidemic of expanded ART, HIV screening, or interventions to reduce risk behavior. Dynamic mathematical model of HIV transmission and disease progression and cost-effectiveness analysis. Published literature. High-risk (injection drug users and men who have sex with men) and low-risk persons aged 15 to 64 years in the United States. Twenty years and lifetime (costs and quality-adjusted life-years [QALYs]). Societal. Expanded HIV screening and counseling, treatment with ART, or both. New HIV infections, discounted costs and QALYs, and incremental cost-effectiveness ratios. One-time HIV screening of low-risk persons coupled with annual screening of high-risk persons could prevent 6.7% of a projected 1.23 million new infections and cost $22,382 per QALY gained, assuming a 20% reduction in sexual activity after screening. Expanding ART utilization to 75% of eligible persons prevents 10.3% of infections and costs $20,300 per QALY gained. A combination strategy prevents 17.3% of infections and costs $21,580 per QALY gained. With no reduction in sexual activity, expanded screening prevents 3.7% of infections. Earlier ART initiation when a CD4 count is greater than 0.350 × 10(9) cells/L prevents 20% to 28% of infections. Additional efforts to halve high-risk behavior could reduce infections by 65%. The model of disease progression and treatment was simplified, and acute HIV screening was excluded. Expanding HIV screening and treatment simultaneously offers the greatest health benefit and is cost-effective. However, even substantial expansion of HIV screening and treatment programs is not sufficient to markedly reduce the U.S. HIV epidemic without substantial reductions in risk behavior. National Institute on Drug Abuse, National Institutes of Health, and Department of Veterans Affairs.

Characteristics of High-Risk HIV-Positive IDUs in Vietnam: Implications for Future Interventions

The HIV epidemic in Vietnam is concentrated primarily among injecting drug users (IDUs). To prevent HIV-1 superinfection and to develop effective HIV prevention programs, data are needed to understand the characteristics of high-risk HIV-positive IDUs. In , we conducted a community-based cross-sectional study among predominately male, out-of-treatment IDUs, aged 18–45, in the Bac Ninh Province, Vietnam. Among 299 male participants, 42.8% were HIV-positive, and among those, 96.9% did not know their status prior to the study. Furthermore, 32% were HIV-positive and had high HIV behavioral risk (having unprotected sex or having shared injecting equipment in the past 6 months). Injecting for ≥3 years, younger age, and pooling money to buy drugs were independently associated with being at high risk for transmitting HIV. IDUs who purchased more than one syringe at a time were less likely to have high HIV behavioral risk. Structural interventions that increase syringe accessibility may be effective in reducing HIV risk behavior among HIV-positive IDUs. Study limitations are noted in the article.

Genetic and Epidemiologic Characterization of HIV-1 Infection In Liaoning Province, China

Although many studies of HIV-1 in China have focused on high-risk injecting drug users and former blood donors in high prevalence regions, little is known about HIV-1 in relatively low prevalence provinces. Here, we compare the epidemiologic and genetic profile of HIV-1 in Liaoning-a low prevalence province-with those identified in China's most severely affected provinces. Two hundred eight HIV-1-positive subjects from all major cities in Liaoning province were recruited between 2000 and 2008. 2.6 kilobase gag-pol sequences were amplified from plasma viral RNA and sequenced directly. The HIV-1 sequences obtained were analyzed using phylogenetic and recombinant approaches. We have shown that in recent years, although HIV-1 prevalence in Liaoning has remained low, the rate of new infection has increased rapidly, particularly among men who have sex with men and heterosexual risk individuals (together comprising >54% of infected individuals in 2007). Furthermore, phylogenetic analysis has identified all major subtypes/circulating recombinant forms of HIV-1 in Liaoning previously identified in high prevalence provinces. Our study also shows close relationships between HIV-1 subtype/circulating recombinant form and certain risk behaviors. Notably, men who have sex with men and heterosexual risk individuals harbor most divergent strains of HIV-1 from multiple high-risk groups. Our study suggested that HIV-1 continues to spread to the general population through sexual contact; Liaoning, therefore, serves as the critical base for the introduction and spread of HIV-1 in northeast China. We believe the transmission patterns suggested herein will help guide public health workers in reducing further spread of HIV-1 within China.

Increased risk for hepatitis C associated with solvent use among Canadian Aboriginal injection drug users

BackgroundSolvent abuse is a particularly serious issue affecting Aboriginal people. Here we examine the association between solvent use and socio-demographic variables, drug-related risk factors, and pathogen prevalence in Aboriginal injection drug users (IDU) in Manitoba, Canada.MethodsData originated from a cross-sectional survey of IDU from December 2003 to September 2004. Associations between solvent use and variables of interest were assessed by multiple logistic regression.ResultsA total of 266 Aboriginal IDU were included in the analysis of which 44 self-reported recent solvent use. Hepatitis C infection was 81% in solvent-users, compared to 55% in those reporting no solvent use. In multivariable models, solvent-users were younger and more likely to be infected with hepatitis C (AOR: 3.5; 95%CI: 1.3,14.7), to have shared needles in the last six months (AOR: 2.6; 95%CI:1.0,6.8), and to have injected talwin & Ritalin (AOR: 10.0; 95%CI: 3.8,26.3).InterpretationHigh hepatitis C prevalence, even after controlling for risky injection practices, suggests that solvent users may form closed networks of higher risk even amongst an already high-risk IDU population. Understanding the social-epidemiological context of initiation and maintenance of solvent use is necessary to address the inherent inequalities encountered by this subpopulation of substance users, and may inform prevention strategies for other marginalized populations.

Access to health and social services for IDU: The impact of a medically supervised injection facility

Injection drug users (IDU) often experience barriers to conventional health-care services, and consequently might rely on acute and emergency services. This study sought to investigate IDU perspectives regarding the impact of supervised injection facility (SIF) use on access to health-care services. Semi-structured qualitative interviews were conducted with 50 Vancouver-based IDU participating in the Scientific Evaluation of Supervised Injecting cohort. Audio-recorded interviews elicited IDU perspectives regarding the impact of SIF use on access to health and social services. Interviews were transcribed verbatim and a thematic analysis was conducted. Fifty IDU, including 21 women, participated in this study. IDU narratives indicate that the SIF serves to facilitate access to health care by providing much-needed care on-site and connects IDU to external services through referrals. Participants' perspectives suggest that the SIF has facilitated increased uptake of health and social services among IDU. Although challenges related to access to care remain in many settings, SIF have potential to promote health by facilitating enhanced access to health-care and social services through a model of care that is accessible to high-risk IDU.

Modelling the transmission of HIV and HCV among injecting drug users in Rawalpindi, a low HCV prevalence setting in Pakistan

Background:In 2007, a survey in Rawalpindi found the prevalence of hepatitis C virus (HCV) in injecting drug users (IDUs) to be low (17%), despite widespread needle/syringe sharing. This analysis uses...