People and places: behavioral settings and personal network characteristics as correlates of needle sharing

Network ethnic homophily and injection equipment sharing among Latinx and White non-Latinx people who inject drugs

Latinx people who inject drugs (PWID) are less likely to engage in injection equipment sharing, but are more vulnerable to injection drug use (IDU)-related morbidity and mortality than Whites. Identifying subgroups of Latinx PWID who do engage in equipment sharing and likely bear the brunt of this health burden is a priority. Ethnic disparities may reflect contextual drivers, including injection networks. Latinx PWID with low ethnic homophily (the proportion of individuals with the same ethnic background) may be more likely to share equipment due to forced distancing from health-protective ethnocultural resources and power imbalances within injection networks. The current study offers a framework and examines how associations between network ethnic homophily and injection equipment sharing differ among 74 Latinx and 170 non-Latinx White PWID in the Chicagoland area (N = 244). Latinx had less homophilous than non-Latinx Whites (p <.001). Ethnic homophily was protective for equipment sharing among Latinx (OR = 0.17, 95%CI [0.77, 0.04], p = .02), but not non-Latinx Whites (OR = 1.66, 95%CI [0.40, 6.93], p = .49). Our findings implicate the need for targeted cultured interventions that focus on Latinx PWID who are more vulnerable to morbidity and mortality, potentially due to less access to ethnic peers.

Spatiotemporal dynamics of epidemiology diseases: mobility based risk and short-term prediction modeling of COVID-19

Nowadays, epidemiological modeling is applied to a wide range of diseases, communicable and non-communicable, namely AIDS, Ebola, influenza, Dengue, Malaria, Zika. More recently, in the context of the last pandemic declared by the World Health Organization (WHO), several studies applied these models to SARS-CoV-2. Despite the increasing number of researches using spatial analysis, some constraints persist that prevent more complex modeling such as capturing local epidemiological dynamics or capturing the real patterns and dynamics. For example, the unavailability of: (i) epidemiological information such as the frequency with which it is made available; (ii) sociodemographic and environmental factors (e.g., population density and population mobility) at a finer scale which influence the evolution patterns of infectious diseases; or (iii) the number of cases information that is also very dependent on the degree of testing performed, often with severe territorial disparities and influenced by context factors. Moreover, the delay in case reporting and the lack of quality control in epidemiological information is responsible for biases in the data that lead to many results obtained being subject to the ecological fallacy, making it difficult to identify causal relationships. Other important methodological limitations are the control of spatiotemporal dependence, management of non-linearity, ergodicy, among others, which can impute inconsistencies to the results. In addition to these issues, social contact, is still difficult to quantify in order to be incorporated into modeling processes. This study aims to explore a modeling framework that can overcome some of these modeling methodological limitations to allow more accurate modeling of epidemiological diseases. Based on Geographic Information Systems (GIS) and spatial analysis, our model is developed to identify group of municipalities where population density (vulnerability) has a stronger relationship with incidence (hazard) and commuting movements (exposure). Specifically, our framework shows how to operate a model over data with no clear trend or seasonal pattern which is suitable for a short-term predicting (i.e., forecasting) of cases based on few determinants. Our tested models provide a good alternative for when explanatory data is few and the time component is not available, once they have shown a good fit and good short-term forecast ability.

Characteristics of Individuals Seen as Sources of Social Support in Populations at Increased Risk for HIV

Access to social support from one's social network can serve as a protective factor against HIV infection; however, research exploring the availability of support in diverse populations that include high proportions of people at increased risk for HIV and the characteristics of network members associated with access to such support is limited. Multi-level dyadic analyses of social network data collected from women at risk for HIV and their network members reveal which individual and relationship characteristics of network members are associated with providing emotional, material, and/or health informational support. Results indicate that access to all three types of support was associated with a network member being a friend, a member of a participant's 'core' group, someone whose opinion matters to the respondent, and the respondent trusting them. These findings have implications for interventions designed to increase access to support among individuals at risk for HIV.

Egocentric network characteristics of people who inject drugs in the Chicago metro area and associations with hepatitis C virus and injection risk behavior

BACKGROUND

Hepatitis C (HCV) infection has been rising in the suburban and rural USA, mainly via injection-based transmission. Injection and sexual networks are recognized as an important element in fostering and preventing risky behavior; however, the role of social support networks has received somewhat less attention.

METHODS

Using baseline data from an ongoing longitudinal study, we examined the composition and structure of injection drug use (IDU), sex, and social support networks of young people who inject drugs (aged 18-30) and their injection network members. Lasso logistic regression was used to select a subset of network characteristics that were potentially important predictors of injection risk behaviors and HCV exposure.

RESULTS

Several measures of IDU, sexual, and support network structure and composition were found to be associated with HCV exposure, receptive syringe sharing (RSS), and ancillary equipment sharing. Gender and sexual relationships were important factors for all risk behaviors. Support network characteristics were also important, notably including a protective effect of majority Hispanic support networks for RSS and HCV exposure. Both IDU network residence heterogeneity and support network geography were associated with injection equipment sharing.

CONCLUSIONS

The associations of IDU and support network geography with equipment sharing highlight the need to extend harm reduction efforts beyond urban areas. Greater understanding of support network influences on risk behavior may provide important insights to strengthen the benefits of harm reduction. In considering the probability of HCV transmission, it is important to consider setting and network structures that promote propagation of risk.

Peer presence and familiarity as key factors to reduce cocaine intake in both rats and humans: an effect mediated by the subthalamic nucleus

RATIONALE

Stimulant use, including cocaine, often occurs in a social context whose influence is important to understand to decrease intake and reduce associated harms. Although the importance of social influence in the context of drug addiction is known, there is a need for studies assessing its neurobiological substrate and for translational research.

OBJECTIVES

Here, we explored the influence of peer presence and familiarity on cocaine intake and its neurobiological basis. Given the regulatory role of the subthalamic nucleus (STN) on cocaine intake and emotions, we investigated its role on such influence of social context on cocaine intake.

METHODS

We first compared cocaine consumption in various conditions (with no peer present or with peers with different characteristics: abstinent peer or drug-taking peer, familiar or not, cocaine-naive or not, dominant or subordinate) in rats (n = 90). Then, with a translational approach, we assessed the influence of the social context (alone, in the group, in a dyad with familiar or non-familiar peers) on drug intake in human drug users (n = 77).

RESULTS

The drug consumption was reduced when a peer was present, abstinent, or drug-taking as well, and further diminished when the peer was non-familiar. The presence of a non-familiar and drug-naive peer represents key conditions to diminish cocaine intake. The STN lesion by itself reduced cocaine intake to the level reached in presence of a non-familiar naive peer and affected social cognition, positioning the STN as one neurobiological substrate of social influence on drug intake. Then, the human study confirmed the beneficial effect of social presence, especially of non-familiar peers.

CONCLUSION

Our results indirectly support the use of social interventions and harm reduction strategies and position the STN as a key cerebral structure to mediate these effects.

Would I Have Your Support? Family Network Features and Past Support Exchanges Associated with Anticipated Support for a Substance Problem

Objective

Assessment of social processes underlying anticipation for recovery-related support from family in the event of a substance problem. We drew from literature on social support, substance use, and social networks to develop a path model connecting emotionally close family relationships, closeness among members in the wider family network (density), previous emotional support exchanges, and anticipated support.

Subjects and Methods

We used a sample from the 2019 Nebraska Annual Social Indicators Survey (284 adults; 57% female; 94% white; 46.26% living in rural areas) and employed generalized structural equation modeling with logistic regression equations for our binary dependent variable (anticipated support).

Results

Denser family networks were associated with individuals' close relations with family (b = .18, p < .001), close family relations were associated with support received by (b = .25, p < .05) and given to (b = .47, p < .001) family, and only support given to family increased the odds of anticipated support (IRR = 4.32, CI = 1.13, 16.48).

Conclusions

Family-wide dynamics are important for understanding how support exchange relates to anticipated support. Prioritizing efforts to strengthen family relationships and improve the likelihood that at-risk individuals, especially in rural areas, can overcome substance problems is important.

Engaging People Who Inject Drugs Living With HIV in Antiretroviral Treatment and Medication for Opioid Use Disorder: Extended Follow-up of HIV Prevention Trials Network (HPTN) 074

BACKGROUND

People who inject drugs (PWID) living with HIV experience inadequate access to antiretroviral treatment (ART) and medication for opioid use disorders (MOUD). HPTN 074 showed that an integrated intervention increased ART use and viral suppression over 52 weeks. To examine durability of ART, MOUD, and HIV viral suppression, participants could re-enroll for an extended follow-up period, during which standard-of-care (SOC) participants in need of support were offered the intervention.

METHODS

Participants were recruited from Ukraine, Indonesia and Vietnam and randomly allocated 3:1 to SOC or intervention. Eligibility criteria included: HIV-positive; active injection drug use; 18-60 years of age; ≥1 HIV-uninfected injection partner; and viral load ≥1,000 copies/mL. Re-enrollment was offered to all available intervention and SOC arm participants, and SOC participants in need of support (off-ART or off-MOUD) were offered the intervention.

RESULTS

The intervention continuation group re-enrolled 89 participants, and from week 52 to 104, viral suppression (<40 copies/mL) declined from 41% to 29% (estimated 9.4% decrease per year, 95% CI -17.0%; -1.8%). The in need of support group re-enrolled 94 participants and had increased ART (re-enrollment: 55%, week 26: 69%) and MOUD (re-enrollment: 16%, week 26: 25%) use, and viral suppression (re-enrollment: 40%, week 26: 49%).

CONCLUSIONS

Viral suppression declined in year 2 for those who initially received the HPTN 074 intervention and improved maintenance support is warranted. Viral suppression and MOUD increased among in need participants who received intervention during the study extension. Continued efforts are needed for widespread implementation of this scalable, integrated intervention.

Social network predictors of recent and sustained injection drug use cessation: findings from a longitudinal cohort study

BACKGROUND AND AIMS

The US opioid crisis has led to increases in overdose fatalities and the incidence of HIV, hepatitis C and other infections. This analysis examines social network predictors of recent (self-report injection followed by non-injection) and sustained (self-report non-injection at two consecutive visits among those who previously injected) injection cessation in Appalachian Kentucky.

DESIGN

Data were collected through bi-annual longitudinal assessments for Social Networks among Appalachian People (SNAP; 2008-17). Using logistic regression with generalized estimating equations that clustered on individuals, we regressed non-injection status on the number of social network members who (a) did not inject and (b) recently stopped injecting and tested for interactions between each social network exposure and prior non-injection status. Social network exposures were self-reported.

SETTING

Rural eastern Kentucky, USA.

PARTICIPANTS

Participants entered the analysis only after reporting recent injection and had to have had at least two consecutive study visits (n = 326).

MEASUREMENTS

Interviewer-administered surveys collected individual-level socio-demographics, recent (past 6 months) drug use behaviors and the names of recent social support, sex and drug-use partners.

FINDINGS

After adjusting for confounders, the number of non-injecting social network members was positively associated with recent/sustained injection cessation (adjusted odds ratio = 1.27; 95% confidence interval = 1.13-1.42) and having more social network members was associated with reduced odds of recent/sustained injection cessation. The number of previously injecting social network members who had recently stopped injecting was not statistically significantly associated with injection cessation. Neither of the interactions we tested for was statistically significant, suggesting that the relationships may be similar for those who recently stopped injecting versus had not injected for at least 1 year.

CONCLUSIONS

For each additional network member who did not inject drugs, there was an increased odds of recent and sustained injection cessation among people with a history of injection drug use in Appalachian Kentucky.

Daily activity spaces and drug use among female sex workers living with HIV in the Dominican Republic

The purpose of this study was to explore the daily activity spaces of female sex workers living with HIV in the Dominican Republic and assess the relationship between activity path and location-based risk exposure measures and daily drug use. The study employed a micro-longitudinal observational study design using an innovative 7-day travel diary to capture daily activity routes and a 7-day mobile health (mHealth) daily diary to collect daily substance use behaviors among 51 female sex workers. To estimate between-subject variability, a series of crude and adjusted modified log-Poisson repeated measures regression models with generalized estimating equations, clustering by individual with a compound symmetry working correlation structure were fit to estimate the relative risks and 95% confidence intervals. Controlling for individual level factors, findings showed that female sex workers exposed to a higher number of risk outlets (e.g., liquor stores, bars, hotels, nightclubs, brothels, etc.) within 200 and 100-meters of sex work locations were at an increased risk of daily drug use (RRadj: 1.03, 95%CI: 1.01, 1.05, RRadj: 1.05, 95%CI: 1.01, 1.09). No association was detected between activity path exposure and daily drug use. These findings illustrate the importance of moving beyond static residential neighborhood boundaries for measuring risk exposures and highlight the significant role that daily work environments have on drug harms among a highly stigmatized and vulnerable population.

Competing forces of withdrawal and disease avoidance in the risk networks of people who inject drugs

We analyze a network of needle-sharing ties among 117 people who inject drugs (PWID) in rural Puerto Rico, using exponential random graph modeling to examine whether network members engage in partner restriction to lower their risk of contracting HIV or hepatitis C (HCV), or in informed altruism to prevent others from contracting these infections. Although sharing of used syringes is a significant risk factor for transmission of these diseases among PWID, we find limited evidence for partner restriction or informed altruism in the network of reported needle-sharing ties. We find however that sharing of needles is strongly reciprocal, and individuals with higher injection frequency are more likely to have injected with a used needle. Drawing on our ethnographic work, we discuss how the network structures we observe may relate to a decision-making rationale focused on avoiding withdrawal sickness, which leads to risk-taking behaviors in this poor, rural context where economic considerations often lead PWID to cooperate in the acquisition and use of drugs.

Injection drug network characteristics as a predictor of injection behaviour

Social network characteristics of people who inject drugs (PWID) have previously been flagged as potential risk factors for HCV transmission such as increased injection frequency. To understand the role of the injecting network on injection frequency, we investigated how changes in an injecting network over time can modulate injecting risk behaviour. PWID were sourced from the Networks 2 Study, a longitudinal cohort study of PWID recruited from illicit drug street markets across Melbourne, Australia. Network-related correlates of injection frequency and the change in frequency over time were analysed using adjusted Cox Proportional Hazards and Generalised Estimating Equations modelling. Two-hundred and eighteen PWID followed up for a mean (s.d.) of 2.8 (1.7) years were included in the analysis. A greater number of injecting partners, network closeness centrality and eigenvector centrality over time were associated with an increased rate of infection frequency. Every additional injection drug partner was associated with an increase in monthly injection frequency. Similarly, increased network connectivity and centrality over time was also associated with an increase in injection frequency. This study observed that baseline network measures of connectivity and centrality may be associated with changes in injection frequency and, by extension, may predict subsequent HCV transmission risk. Longitudinal changes in network position were observed to correlate with changes in injection frequency, with PWID who migrate from the densely-connected network centre out to the less-connected periphery were associated with a decreased rate of injection frequency.

Characterizing latent classes of social support among persons who inject drugs

BACKGROUND

Social network members influence risk and health behaviors, yet little is known about the support that persons who inject drugs (PWID) receive from their closest ties.

METHODS

970 participants from the AIDS Linked to the IntraVenous Experience (ALIVE) study completed a social network survey between April 2016 and June 2017 about their five closest ties. Our analysis: 1) identified latent classes of support received by participants; 2) determined whether class membership differed by current (≤12 months) vs. former (>12 months) injection drug use; 3) compared classes of support by individual and network characteristics.

RESULTS

970 participants listed 3,388 network members. We identified three support classes: (1) Moderate (n = 249): probabilities of support <0.40; (2) High (n = 366): probabilities of support 0.58-0.82; (3) Very high (n = 355): probabilities of support 0.91-0.99. In adjusted analysis compared to moderate support, the odds of high and very high support increased as the mean age of network members increased (Adjusted Odds Ratio [AOR]:1.03; 95 % CI: 1.01, 1.05) and as the number of network members with whom they interacted daily increased (AOR-high: 1.33; 95 % CI:1.14, 1.56 and AOR-very high: 1.54; 95 % CI: 1.30, 1.83). While current injection drug use was associated with lower unadjusted odds of high and very high support, the associations were not statistically significant in adjusted analysis.

CONCLUSIONS

Support was higher among networks of older ties and more frequent interaction, but differences did not appear to be driven by injection drug use status. Findings point to the importance of the closest social ties.

Peer influence of injection drug use cessation among dyads in rural eastern Kentucky

BACKGROUND

This analysis aims to assess whether injection drug use cessation among peers predicts injection drug use cessation among individuals and explores whether this association varies by relationship type and strength.

METHODS

Data were collected through baseline and 6-month assessments for the Social Networks among Appalachian People study (2008-2011). Interviewer-administered surveys collected sociodemographic and drug use behaviors (past 6 months and lifetime). Participants also listed sex, drug use, and social support partners (past 6 months). Listed names were cross-referenced with survey participants to identify relationships between study participants. The analytic sample was further restricted to include only those relationship pairs where both individuals reported a history of injection drug use at baseline (n = 244 unique individuals and 746 dyads). We fit a generalized estimating equations logistic regression model to (1) assess the relationship between peer injection cessation and individual injection cessation and (2) determine whether the strength of this association differs by relationship-level variables (i.e., relationship role, relationship type, relationship duration, frequency of interaction, residential proximity).

RESULTS

Overall, those with a network member who ceased injection drug use were more likely to stop injecting over the following 6-month period (AOR=1.65). The magnitude of this association was greater for social support partners (AOR=2.95), family members (AOR=3.56), those with whom the participant interacted at least daily (AOR=2.17), and those who the participant knew longer (AOR=2.09). Further, among family members, the effect size was greater when relationships were further restricted to immediate family members (AOR=5.35).

CONCLUSION

Our findings suggest that in this rural community, closer, more supportive relationships, may be more influential for modeling injection cessation; however, relationship-types were not mutually exclusive so differences in effect size across strata may not be statistically significant. In this setting, social support through the recovery process (including cessation attempts with peers) may increase likelihood of injection cessation.

Sources of Stress among Adults with Co-occurring Drug Use and Depressive Symptoms

Stress, drug use, and depression are interconnected, but less is understood about sources of stress among adults with co-occurring drug use and depressive symptoms. The current study aimed to identify sources of stress and correlates among these adults. Data come from a cross-sectional baseline survey, including participants (n = 336) 18 to 55 years old, who reported past 6-month heroin or cocaine use and depressive symptoms. Exploratory factor analysis was conducted to identify sources of stress. Chi-square and multivariable Poisson regression with robust error variance were used to explore correlates of each factor. Three sources of stress were identified: financial stress related to drugs, stress due to community features, and stress involving a person's network. Past 6-month injection drug use (aPR = 1.34, 95% CI 1.07-1.67), perceived lack of control over drug use (aPR = 1.80, 95% CI 1.41-2.30), and difficulty abstaining from drug use (aPR = 1.55, 95% CI 1.22-1.97) were associated with an increased risk of high drug-related financial stress. Neighborhood disorder (aPR = 2.42, 95% CI 1.80-3.24) and sleeping on the street (aPR = 1.37, 95% CI 1.04-1.80) were associated with an increased risk of high community-level stress. Past 6-month injection drug use (aPR = 1.28, 95% CI 1.04-1.58), perceived lack of control over drug use (aPR = 1.37, 95% CI 1.10-1.70), and drug use stigma was associated with an increased prevalence of high drug network stress (aPR = 1.32, 95% CI 1.05-1.65). Stress is a complex construct, including distinct sources and correlates. Further understanding of sources of stress is beneficial in recognizing potentially modifiable challenges faced by individuals who use drugs and experience depressive symptoms.

Social Networks of Substance-Using Populations: Key Issues and Promising New Approaches for HIV

PURPOSE OF REVIEW

This paper presents recent literature on substance using networks and HIV, highlighting renewed and emerging themes in the field. The goal is to draw attention to research that holds considerable promise for advancing our understanding of the role of networks in shaping behaviors, while also providing critical information for the development of interventions, programs, and policies to reduce HIV and other drug-related harms.

RECENT FINDINGS

Recent research advances our understanding of networks and HIV, including among understudied populations, and provides new insight into how risk environments shape the networks and health of substance-using populations. In particular, the integration of network approaches with molecular epidemiology, research on space and place, and intervention methods provides exciting new avenues of investigation. Continued advances in network research are critical to supporting the health and rights of substance-using populations and ensuring the development of high-impact HIV programs and policies.

Regional differences between people who inject drugs in an HIV prevention trial integrating treatment and prevention (HPTN 074): a baseline analysis

INTRODUCTION

People who inject drugs (PWID) experience high HIV incidence and face significant barriers to engagement in HIV care and substance use treatment. Strategies for HIV treatment as prevention and substance use treatment present unique challenges in PWID that may vary regionally. Understanding differences in the risk structure for HIV transmission and disease progression among PWID is essential in developing and effectively targeting intervention strategies of HIV treatment as prevention.

METHODS

We present a baseline analysis of HIV Prevention Trials Network (HPTN) 074, a two-arm, randomized controlled trial among PWID in Indonesia (n = 258), Ukraine (n = 457) and Vietnam (n = 439). HPTN 074 was designed to determine the feasibility, barriers and uptake of an integrated intervention combining health systems navigation and psychosocial counselling for the early engagement of antiretroviral therapy (ART) and substance use treatment for PWID living with HIV. Discordant PWID networks were enrolled, consisting of an HIV-positive index and their HIV-negative network injection partner(s). Among the enrolled cohort of 1154 participants (502 index participants and 652 network partners), we examine regional differences in the baseline risk structure, including sociodemographics, HIV and substance use treatment history, and injection and sexual risk behaviours.

RESULTS

The majority of participants were male (87%), with 82% of the enrolled females coming from Ukraine. The overall mean age was 34 (IQR: 30, 38). Most commonly injected substances included illegally manufactured methadone in Ukraine (84.2%), and heroin in Indonesia (81.8%) and Vietnam (99.5%). Injection network sizes varied by region: median number of people with whom participants self-reported injecting drugs was 3 (IQR: 2, 5) in Indonesia, 5 (IQR: 3, 10) in Ukraine and 3 (IQR: 2, 4) in Vietnam. Hazardous alcohol use, assessed using the Alcohol Use Disorders Identification Test - Alcohol Consumption Questions (AUDIT-C), was prominent in Ukraine (54.7%) and Vietnam (26.4%). Reported sexual risk behaviours in the past month, including having two or more sex partners and giving/receiving money or drugs in exchange for sex, were uncommon among all participants and regions.

CONCLUSIONS

While regional differences in risk structure exist, PWID particularly in Ukraine need immediate attention for risk reduction strategies. Substantial regional differences in risk structure will require flexible, tailored treatment as prevention interventions for distinct PWID populations.

Influence of social network on drug use among clients of methadone maintenance treatment centers in Kunming, China

AIMS

To examine drug use behavior of clients attending Methadone Maintenance Treatment (MMT) programs and its relationship with the clients' social network characteristics.

DESIGN

Cross-sectional study.

SETTING

Four MMT clinics in Kunming, Yunnan province, China.

PARTICIPANTS

324 consecutive MMT clients.

MEASUREMENTS

A structured, self-completed questionnaire on background characteristics and existing social network. Current drug use was assessed by urine test for opiate metabolites.

ANALYSIS

The association between client's social network characteristics and their own current drug use behavior is analysed using multiple logistic regression adjusting for socio-demographic characteristics. Adjusted odds ratios (AOR) with 95% confidence intervals (CI) are obtained to give the strength of the associations.

FINDINGS

MMT clients were more likely to concurrently use heroin while attending MMT if their social network had any of the following characteristics: more than half of the members were older than them (AOR = 1.03, 95% CI = 1.00,1.06), any member had a high level of influence on them (AOR = 6.47, 95% CI = 2.86,14.65) and any member joined them in using drugs (AOR = 1.94, 95% CI = 1.04,3.63). Having a social network member who could provide emotional support (AOR = 0.11, 95% CI = 0.03,0.35), having a spouse and/or child in their social network (AOR = 0.44, 95% CI = 0.24,0.81) and having a social network member with a high level of closeness (AOR = 0.28, 95% CI = 0.09,0.90) were associated with a decreased odds of heroin use.

CONCLUSION

Social networks who could provide MMT clients with emotional support and a close relationship were significant factors for reducing the risk of concurrent drug use among clients attending MMT clinics in Kunming, China. Behavioral interventions should address the role of family and social network members in providing support to these clients.

Post-Traumatic Stress Disorder, Neighborhood Residency and Satisfaction, and Social Network Characteristics among Underserved Women in Baltimore, Maryland

BACKGROUND

Post-traumatic stress disorder (PTSD) prevalence is high, but not well-understood, among women living in urban, impoverished areas. Although previous studies have established social support as an important factor in PTSD development and maintenance, little is known about how perceptions of neighborhood are linked to PTSD. This study examined the relationship between PTSD and social network and neighborhood factors among women with a low socioeconomic status.

METHODS

We analyzed cross-sectional data collected from a human immunodeficiency virus/sexually transmitted infection peer network study in Baltimore, Maryland (n = 438). We used bivariate analyses to examine the associations between PTSD and social network characteristics and time in neighborhood and satisfaction. We then constructed multivariable regression models that controlled for the following with PTSD: homelessness, cocaine/heroin use, and unemployment.

MAIN FINDINGS

Overall, 30% of women had PTSD symptom severity consistent with a clinical diagnosis. In the multivariable model, dissatisfaction with neighborhood block (odds ratio [OR], 1.80; p = .03) and living in one's neighborhood for more than 5 years (OR, 1.69; p = .03) were associated with PTSD. Social network factors that were significantly associated with PTSD included a higher number of network members in conflict with the participant (OR, 1.28; p = .02), presence of a network member who would let the participant stay with them (OR, 0.4; p = .004), and the number of network members with whom the participant socialized (OR, 0.6; p = .04).

CONCLUSIONS

In this sample of impoverished urban women with a high prevalence of PTSD, duration of residency, satisfaction with neighborhood, and network characteristics were found to be strongly associated with PTSD symptom severity.

Needle acquisition patterns, network risk and social capital among rural PWID in Puerto Rico

BACKGROUND

People who inject drugs (PWID) take on significant risks of contracting blood-borne infection, including injecting with a large number of partners and acquiring needles from unsafe sources. When combined, risk of infection can be magnified.

METHODS

Using a sample of PWID in rural Puerto Rico, we model the relationship between a subject's number of injection partners and the likelihood of having used an unsafe source of injection syringes. Data collection with 315 current injectors identified six sources of needles.

RESULTS

Of the six possible sources, only acquisition from a seller (paid or free), or using syringes found on the street, was significantly related to number of partners.

CONCLUSIONS

These results suggest that sources of syringes do serve to multiply risk of infection caused by multi-partner injection concurrency. They also suggest that prior research on distinct forms of social capital among PWID may need to be rethought.

Injection Drug Network Characteristics Are Important Markers of HIV Risk Behavior and Lack of Viral Suppression

BACKGROUND

People who inject drugs (PWID) who are highly connected within their injection drug networks may be important HIV transmission nodes if they frequently share syringes with other PWID and are not engaged in HIV care. In India, HIV transmission fueled by injection drug use is increasing; however, little is known about the associations between injection network size and syringe sharing and viral suppression.

METHODS

We recruited 14,481 PWID between October 2012 and December 2013 by respondent-driven sampling across 15 sites in India. Interviewer-administered questionnaires assessed network characteristics, substance use, HIV testing experience, and access to health services. We used multilevel logistic regression modeling to evaluate the relationship between injection drug network size and (1) syringe sharing at last injection and (2) viral suppression among HIV-positive participants (<150 copies/mL).

FINDINGS

The median injection network size was 3 (interquartile range: 1-5), and 7% of participants injected with >10 members in the past 30 days. PWID who had >10 members in their network were 1.65 times (95% confidence interval: 1.12 to 2.42, P = 0.0111) more likely to have shared a syringe at last injection compared with those in the 0-1 members in their drug networks. In addition, individuals with the largest injection drug networks were 31% (95% confidence interval: 0.53 to 0.90, P = 0.006) less likely to be virally suppressed compared with those in the smallest injection drug networks.

DISCUSSION

Individuals with larger networks may be important in HIV transmission within injection drug networks because they were the most likely to engage in recent syringe sharing and least likely to be virally suppressed.

Social mixing and correlates of injection frequency among opioid use partnerships

BACKGROUND

As resources are deployed to address the opioid overdose epidemic in the USA, it is essential that we understand the correlates of more frequent opioid injections-which has been associated not only with HIV and HCV transmission, but also with overdose risk-to inform the development and targeting of effective intervention strategies like overdose prevention and naloxone distribution programs. However, no studies have explored how characteristics of opioid use partnerships may be associated within injection frequency with opioid partnerships.

METHODS

Using baseline data from a trial of a behavioural intervention to reduce overdose among opioid users in San Francisco, CA, we calculated assortativity among opioid use partnerships by race, gender, participant-reported HIV- and HCV-status, and opioids used using Newman's assortativity coefficient (NC). Multivariable generalized estimating equations linear regression was used to examine associations between individual- and partnership-level characteristics and injection frequency within opioid use partnerships.

RESULTS

Opioid use partnerships (n=134) reported by study participants (n=55) were assortative by race (NC=0.42, 95%CI=0.33-0.50) and participant-reported HCV-status (NC=0.42, 95%CI=0.31-0.52). In multivariable analyses, there were more monthly injections among sexual/romantic partnerships (β=114.4, 95%CI=60.2-168.7, p<0.001), racially concordant partnerships reported by white study participants (β=71.4, 95%CI=0.3-142.5, p=0.049), racially discordant partnerships reported by African American study participants (β=105.7, 95%CI=1.0-210.5, p=0.048), and partnerships in which either member had witnessed the other experience an overdose (β=81.8, 95%CI=38.9-124.6, p<0.001).

CONCLUSION

Social segregation by race and HCV-status should potentially be considered in efforts to reach networks of opioid users. Due to higher injection frequency and greater likelihood of witnessing their partners experience an overdose, individuals in sexual/romantic opioid use partnerships, white individuals in racially homogenous partnerships, and African American individuals in heterogeneous partnerships may warrant focused attention as part of peer- and network-based overdose prevention efforts, as well as broader HIV/HCV prevention strategies. Developing and targeting overdose prevention education programs that provide information on risk factors and ways to identify overdose, as well as effective responses, including naloxone use and rescue breathing, for more frequently injecting networks may help reduce opioid morbidity and mortality in these most at risk groups.

Theoretical Implications of Gender, Power, and Sexual Scripts for HIV Prevention Programs Aimed at Young, Substance-Using African-American Women

HIV continues to be a major public health problem for African-American (AA) women, and the burden of new cases to our society is significant because each case is at risk of infecting others. Substance use worsens the risk of HIV transmission to AA women. We provide specific recommendations to move the concept of tailoring HIV prevention interventions for substance users forward by focusing on young, sexually active, substance-using AA women and applying a culturally relevant revision to existing theoretical frameworks to include the Sexual Script Theory and the Theory of Gender and Power. We encourage use of these theories to guide adaptation of interventions to demonstrate efficacy within this hard-to-reach population. Consistent use of theories designed to exploit powerlessness and sexual scripts as barriers to adoption of protective sexual behaviors has potential to permeate sexual and substance use networks among African-Americans. This recommendation is being made because this theoretical framework has not been used in HIV prevention interventions targeting young, sexually active, substance-using AA women.

Acute HIV infection transmission among people who inject drugs in a mature epidemic setting

OBJECTIVE

Estimates for the contribution of transmission arising from acute HIV infections (AHIs) to overall HIV incidence vary significantly. Furthermore, little is known about AHI-attributable transmission among people who inject drugs (PWID), including the extent to which interventions targeting chronic infections (e.g. HAART as prevention) are limited by AHI transmission. Thus, we estimated the proportion of transmission events attributable to AHI within the mature HIV epidemic among PWID in New York City (NYC).

DESIGN

Modeling study.

METHODS

We constructed an interactive sexual and injecting transmission network using an agent-based model simulating the HIV epidemic in NYC between 1996 and 2012. Using stochastic microsimulations, we cataloged transmission from PWID based on the disease stage of index agents to determine the proportion of infections transmitted during AHI (in primary analyses, assumed to last 3 months).

RESULTS

Our calibrated model approximated the epidemiological features of the mature HIV epidemic in NYC between 1996 and 2012. Annual HIV incidence among PWID dropped from approximately 1.8% in 1996 to 0.7% in 2012. Over the 16-year period, AHI accounted for 4.9% (10th/90th percentile: 0.1-12.3%) of incident HIV cases among PWID. The annualized contribution of AHI increased over this period from 3.6% in 1996 to 5.9% in 2012.

CONCLUSION

Our results suggest that, in mature epidemics such as NYC, between 3% and 6% of transmission events are attributable to AHI among PWID. Current HIV treatment as prevention strategies are unlikely to be substantially affected by AHI-attributable transmission among PWID populations in mature epidemic settings.

HIV incidence among people who inject drugs (PWIDs) in Ukraine: results from a clustered randomised trial

BACKGROUND

HIV prevalence among people who inject drugs (PWID) in Ukraine is among the highest in the world. In this study, we aimed to assess whether a social network intervention was superior to HIV testing and counselling in affecting HIV incidence among PWID. Although this was not the primary aim of the study, it is associated with reducing drug and sex risk behaviours, which were primary aims.

METHODS

In this clustered randomised trial, PWID who were 16 years of age or older, had used self-reported drug injection in the past 30 days, were willing to be interviewed for about 1 hour and tested for HIV, were not too impaired to comprehend and provide informed consent, and, for this paper, who tested HIV negative at baseline were recruited from the streets by project outreach workers in three cities in southern and eastern Ukraine: Odessa, Donetsk, and Nikolayev. Index or peer leaders, along with two of their network members, were randomly assigned (1:1) by the study statistician to the testing and counselling block (control group) or the testing and counselling plus a social network intervention block (intervention group). No stratification or minimisation was done. Participants in the network intervention received five sessions to train their network members in risk reduction. Those participants assigned to the control group received no further intervention after counselling. The main outcome of this study was HIV seroconversion in the intent-to-treat population as estimated with Cox regression and incorporating a γ frailty term to account for clustering. This trial is registered with ClinicalTrial.gov, number NCT01159704.

FINDINGS

Between July 12, 2010, and Nov 23, 2012, 2304 PWIDs were recruited, 1200 of whom were HIV negative and are included in the present study. 589 index or peer leaders were randomly assigned to the control group and 611 were assigned to the intervention group. Of the 1200 HIV-negative participants, 1085 (90%) were retained at 12 months. In 553·0 person-years in the intervention group, 102 participants had seroconversion (incidence density 18·45 per 100 person-years; 95% CI 14·87-22·03); in 497·1 person-years in the control group 158 participants seroconverted (31·78 per 100 person-years; 26·83-36·74). This corresponded to a reduced hazard in the intervention group (hazard ratio 0·53, 95% CI 0·38-0·76, p=0·0003). No study-related adverse events were reported.

INTERPRETATION

These data provide strong support for integrating peer education into comprehensive HIV prevention programmes for PWID and suggest the value in developing and testing peer-led interventions to improve access and adherence to pre-exposure prophylaxis and antiretroviral therapy.

FUNDING

The National Institute on Drug Abuse.

Triangulating Syndemic Services and Drug Treatment Policy: Improving Drug Treatment Portal Locations in Baltimore City

THE PROBLEM

The prevalence of injection drug use (IDU) and incidence of human immunodeficiency virus (HIV) remain high in Baltimore, where IDU is a primary HIV risk factor. Substance use disorders and HIV are related syndemically--their causes and consequences interact synergistically. Baltimore is increasingly considering the syndemic relationship of substance use disorders, IDU, and HIV in making decisions about drug treatment funding and location.

PURPOSE OF ARTICLE

Our goal was to empirically identify the optimal location of new drug treatment programs through the development and application of a novel, practical tool.

KEY POINTS

Syndemic triangles were constructed to measure and visualize unmet need for drug treatment services. These data were used to determine priority zones for new treatment centers.

CONCLUSIONS

The application of this tool helped inform strategies for locating drug treatment services in Baltimore, and its successful use suggests its potential value in other metropolitan areas.

Ascertaining the Need for a Supervised Injecting Facility (SIF): The Burden of Public Injecting in Montreal, Canada

Empirical evidence suggests that a key prerequisite for a supervised injection facility (SIF) utilization is the existence of an “open drug scene,” where users publicly inject drugs. This study seeks to determine the extent and profile of public injecting among injecting drug users (IDUs) in Montreal, Canada, where pilot SIFs are under consideration. A cross-sectional study of IDUs who injected publicly at least once in the previous month was appended to an HIV-risk surveillance study among Montreal IDUs (SurvUDI study). Of 650 SurvUDI participants interviewed between June 2001 and February 2002, 59% were eligible. A dose-response relationship emerged between intensity of public injecting and several drug-use and risk-related characteristics. Regardless of housing stability, IDUs persistently and, often preferably, publicly injected due to habit, dependence, or need to conceal their status. Despite lacking a classical open drug scene, public injecting is common among Montreal IDUs, warranting the consideration of an SIF for this population.

Beyond equipment distribution in Needle and Syringe Programmes: an exploratory analysis of blood-borne virus risk and other measures of client need

Background

Despite high levels of equipment distribution through Needle and Syringe Programmes (NSPs) in Australia, the levels of reuse of equipment among people who inject drugs remain concerning. This paper used an exploratory analysis to examine the needs of NSP client that could be addressed by NSPs to enhance service impact and blood-borne virus risk practices.

Methods

People who inject drugs were recruited from six NSP sites in Sydney, Australia, to undertake a self-completed survey.

Results

Using the responses of 236 NSP client participants, three factors were identified in an exploratory factor analysis: recent risky injection (Eigenvalue 3.63, 20.2 % of variance); disadvantage and disability (Eigenvalue 2.26, 12.5 % of variance); and drug use milieu (Eigenvalue 1.50, 8.4 % of variance). To understand the distribution of these factors, the standardised factor scores were dichotomised to explore those participants with ‘above average’ vulnerability on each factor. A small group of NSP clients reported a cluster of vulnerability measures. Most participants (55.5 %) reported vulnerability on none or only one factor, indicating that 45.5 % could be considered as having double (35.6 %) or triple (8.9 %) vulnerability.

Conclusions

These results challenge NSPs to understand the heterogeneity among their client group and develop programmes that respond to their clients’ range of needs beyond those immediately associated with blood-borne virus (BBV) risk. This paper contributes to the growing evidence base regarding the need for BBV prevention efforts to examine strategies beyond equipment distribution.

"It's Not What You Know but Who You Know": Role of Social Capital in Predicting Risky Injection Drug Use Behavior in a Sample of People who Inject Drugs in Baltimore City

BACKGROUND

Injection drug use is the third highest risk factor for HIV transmission. Injection drug users, marginalized population, continue to be at threat for several health problems, including HIV, Hepatitis B & C and drug overdose. The area of social capital and risk behaviors is understudied. The current study aims to prospectively assess the relationship between social capital and the risk behaviors associated with injection drug use.

METHODS

The sample of the present study is a subset of 130 drug users who reported injection drug use (IDU) at both baseline and first follow-up wave for assessing the relationship between social capital and needle sharing in the city of Baltimore, MD. Factor analysis, structural equation modeling and multivariate logistic regression were conducted to explore these relationships.

RESULTS

A single-factor model fit well with factor loadings ranging from .20 to .95. Social capital is shown to be significantly and inversely associated (p<.05) with 35% decreased odds of the risk of sharing needles with every unit increase in social capital (AOR: 0.65, 95% CI: 0.06, 0.84).

CONCLUSION

The result from this study can be used to inform and fill gaps in the field of harm reduction. The interplay between social support, social participation and norms of trust, reciprocity generated from the index's social network and its relationship with behavior of needle sharing demonstrates that these leverage points should be emphasized in future harm reduction interventions.

The role of social networks and geography on risky injection behaviors of young persons who inject drugs

BACKGROUND

Little is known about young persons who inject drugs (PWID), who are increasingly from suburban communities and predominantly non-Hispanic white.

METHODS

We conducted a cross-sectional personal network (egocentric) and geographic study of young PWID and their drug-using, sexual, and support network members in 2012-13 in metropolitan Chicago, Illinois, U.S.

RESULTS

We enrolled 164 young (median age=26), mostly male (65%), non-Hispanic white PWID (71%), with a self-reported HCV prevalence of 13%. Many (59%) reported multiple residences (i.e., were transient) in the past year, 45% of whom reported living in both urban and suburban places (i.e., were cross-over transients). In multivariable analyses that adjusted for participant and network member characteristics, (1) large injection networks were more common among homeless participants; and (2) syringe sharing was (a) highest among cross-over transients compared to suburban (OR=4.19 95% CI 1.69-10.35) and urban only residents (OR=2.91 95% CI 1.06-8.03), (b) higher among HCV-unknown compared HCV-negative participants (OR=4.62 95% CI 1.69-10.35), (c) more likely with network members who were cross-over transients compared to urban (OR=4.94, 95% CI 2.17-11.23) and (d) less likely with network members with HCV-unknown compared to HCV-negative status (OR=0.4 95% CI 0.19-0.84).

CONCLUSIONS

We identified homelessness as a significant risk factor for large networks and cross-over transience as a significant risk factor for syringe sharing. Further research is needed to understand the role of geographic factors promoting higher risk among these crossover transient PWID.

Love on lockdown: how social network characteristics predict separational concurrency among low income African-American women

One out of nine African-American men between the ages of 20 and 34 is behind bars, resulting in many African-American women losing their primary romantic partners to incarceration. Research suggests that partner incarceration may contribute to increased risk of sexually transmitted infections (STIs)/human immunodeficiency virus (HIV); however, factors associated with women's decisions to begin new sexual partnerships following partner incarceration (i.e., separational concurrency) have not been well studied. This study examined the social context relevant to initiating separational concurrency, following incarceration of a primary male partner. Cross-sectional secondary data analysis of 6-month follow-up data from the CHAT Project, a social-network based HIV/sexually transmitted disease (STD) prevention study in Baltimore, MD, USA. Participants were N = 196 African-American women, who reported ever having had a partner who was incarcerated for at least 6 months during the relationship. The majority (81.5%) of women were unemployed with a mean age of 41.7 years. Over half of the sample (59.5%) reported having used crack or heroin at least once in the previous 12 months; 48.5% of the women had experienced physical abuse, with over half of the sample reporting a lifetime history of emotional abuse (54.6%). Separational concurrency, defined as answering yes to the item, "While [your] partner was incarcerated, did you have any other sexual partners?," was the primary outcome measure. After adjusting for age, drug use and unemployment the multiple logistic regression model found that women who reported a history of physical or emotional abuse were over two times as likely to report separational concurrency than women without an abuse history [adjusted odds ratio (AOR), 2.24; 95% CI, 1.24, 4.05; p = .007 and AOR, 2.44; 95% CI, 1.33, 4.46; p = .004, respectively]. Individuals who reported a higher number of drug-using sex partners (AOR, 2.49; 95% CI, 1.4, 4.5; p = .002), sex exchange partners (AOR, 4.0; 95% CI, 1.8 8.9; p = .001), and sexual partners who engaged in concurrency (AOR: 2.67; 95% CI: 1.5, 4.8; p = .001) were significantly more likely to report separational concurrency. Conversely, participants who reported more female kin in their social networks (AOR, .808; 95% CI, .67, .97; p = .025), having known network members a longer time (AOR, .997; 95% CI, .993, .999; p = .043), and higher levels of trust for network members (AOR, .761; 95% CI, .63, .92; p = .005) were significantly less likely to report separational concurrency. Results of this study demonstrate that social network characteristics may be crucial to understanding separational concurrency among African-American urban women who have lost a partner to incarceration. Social network and other resource-based interventions, which provide instrumental, social, and economic resources to women who have experienced the loss of a partner to incarceration, may be important tools in empowering women and helping to reduce the disproportionate burden of STIs/HIV among low income, African-American women.

Capturing illicit drug use where and when it happens: an ecological momentary assessment of the social, physical and activity environment of using versus craving illicit drugs

AIMS

To understand the environmental and contextual influences of illicit cocaine and heroin use and craving using mobile health (mHealth) methods.

DESIGN

Interactive mHealth methods of ecological momentary assessment (EMA) were utilized in the Exposure Assessment in Current Time (EXACT) study to assess drug use and craving among urban drug users in real time. Participants were provided with mobile devices and asked to self-report every time they either craved (without using) or used heroin or cocaine for 30 days from November 2008 through May 2013.

SETTING

Baltimore, MD, USA.

PARTICIPANTS

A total of 109 participants from the AIDS Linked to the IntraVenous Experience (ALIVE) study.

MEASUREMENTS

For each drug use or craving event, participants answered questions concerning their drug use, current mood and their social, physical and activity environments. Odds ratios (OR) of drug use versus craving were obtained from logistic regression models with generalized estimating equations of all reported events.

FINDINGS

Participants were a median of 48.5 years old, 90% African American, 52% male and 59% HIV-infected. Participants were significantly more likely to report use rather than craving drugs if they were with someone who was using drugs [adjusted odds ratio (aOR) = 1.45, 95% confidence interval (CI) = 1.13, 1.86), in an abandoned space (aOR = 6.65, 95% CI = 1.78, 24.84) or walking/wandering (aOR = 1.68, 95% CI = 1.11, 2.54). Craving drugs was associated with being with a child (aOR = 0.26, 95% CI = 0.12, 0.59), eating (aOR = 0.54, 95% CI = 0.34, 0.85) or being at the doctor's office (aOR = 0.31, 95% CI = 0.12, 0.80).

CONCLUSIONS

There are distinct drug using and craving environments among urban drug users, which may provide a framework for developing real-time context-sensitive interventions.

Outlier populations: individual and social network correlates of solvent-using injection drug users

Objective

We previously identified a high prevalence of Hepatitis C (HCV) amongst solvent-using injection drug users (S-IDU) relative to other injection drug users within the same locality. Here we incorporated social network variables to better characterize some of the behavioural characteristics that may be putting this specific subgroup of IDU at elevated disease risk.

Methods

A cross-sectional survey of at-risk populations was carried out in Winnipeg, Canada in 2009. Individuals reporting any history of injection drug and/or solvent use were included in the study. Associations between subgroup membership, infection with HCV and HIV and individual and social network variables were examined.

Results

In relation to other IDU, S-IDU were more likely to be infected with HCV, to report ever having shared a syringe, and to associate with other IDU. They were further differentiated in terms of their self-reported sexual orientation, ethnicity and in the injection drugs typically used.

Conclusion

Solvent use stands as a proxy measure of numerous other characteristics that put this group of IDU at higher risk of infection. Provision of adequate services to ostracized subpopulations may result in wider population-level benefits.

Social support and HIV-related risk behaviors: a systematic review of the global literature

Existing empirical evidence has well documented the role of social support in both physical and psychological well-being among various populations. In the context of HIV prevention, the rapid increase of studies on social support merits a systematic review to synthesize the current global literature on association between social support and HIV-related risk behaviors. The current review reveals a complex picture of this relationship across diverse populations. Existing studies indicate that higher levels of social support are related to fewer HIV-related risk behaviors among female sex workers and people living with HIV/AIDS and heterosexual adults in general. However, influences of social support on HIV-related risk behaviors are inconsistent within drug users, men who have sex with men and adolescents. These variations in findings may be attributed to different measurement of social support in different studies, specific context of social support for diverse population, or various characteristics of the social networks the study population obtained support from. Future studies are needed to explore the mechanism of how social support affects HIV-related risk behaviors. HIV prevention intervention efforts need to focus on the positive effect of social support for various vulnerable and at-risk populations. Future efforts also need to incorporate necessary structure change and utilize technical innovation in order to maximize the protective role of social support in HIV risk prevention or reduction.

Social network characteristics and HIV risk among African American, Asian/Pacific Islander, and Latino men who have sex with men

OBJECTIVES

To examine how social networks influence HIV risk among US racial/ethnic minority men who have sex with men (MSM) and whether the associations of social network characteristics with risk vary by race/ethnicity.

METHODS

A chain-referral sample of 403 African American, 393 Asian/Pacific Islander, and 400 Latino MSM recruited in Los Angeles County, California, completed a questionnaire, which asked about their egocentric social networks, safer sex peer norms, and male anal intercourse partners. HIV-nonconcordant partnerships were those reported by respondents as serodisconcordant or where self and/or partner serostatus was unknown.

RESULTS

Overall, 26% of the sample reported HIV-nonconcordant unprotected anal intercourse (UAI) with a nonprimary male partner in the previous 6 months. In a generalized estimating equation (GEE) logistic model that controlled for race/ethnicity, age, nativity, incarceration history, and HIV status, being in a more dense network was associated with less HIV-nonconcordant UAI [adjusted odds ratio (AOR) = 0.92, 95% confidence interval (CI): 0.86 to 0.99, P = 0.0467]. In addition, the effect of safer sex peer norms on HIV-nonconcordant UAI was moderated by ego-alter closeness (P = 0.0021). Safer sex peer norms were protective among those reporting "medium" or "high" ego-alter closeness (AOR = 0.70, 95% CI: 0.52 to 0.95, P = 0.0213 and AOR = 0.48, 95% CI: 0.35 to 0.66, P < 0.0001, respectively), but not among those reporting "low" ego-alter closeness (AOR = 0.96, 95% CI: 0.63 to 1.46, P = 0.8333). The effects of density, closeness, and norms on HIV-nonconcordant UAI did not differ by race/ethnicity.

CONCLUSIONS

The significant association of social network characteristics with UAI point to network-level factors as important loci for both ongoing research and HIV prevention interventions among US MSM of color.

Safe havens and rough waters: networks, place, and the navigation of risk among injection drug-using Malaysian fishermen

BACKGROUND

HIV prevalence among Malaysian fishermen is ten times that of the general population. Fishing boats are a key place where drug use occurs, but we know little about how these environments shape HIV risk behaviour. Utilizing Rhodes' 'risk environment' framework, we assessed drug use contexts and how characteristics of place associated with fishing and fishermen's social networks served as key axes along which drug use and HIV risk behaviour occurred.

METHODS

Data were collected during 2009-2011 in Kuantan, a fishing port on the eastern coast of Malaysia, and include 28 in-depth interviews and 398 surveys collected using RDS. Logistic regression was used to determine the effect of occupational, network and risk environment characteristics on unsafe injection behaviour and access to clean needles/syringes; qualitative data were coded and analyzed thematically.

RESULTS

Drug injecting was common and occurred on boats, often with other crewmembers. Captains and crewmembers were aware of drug use. Unsafe injection practices were significantly associated with having a larger proportion of drug injectors in network (OR=3.510, 95% CI=1.053-11.700) and having a captain provide drugs for work (OR=2.777, 95% CI=1.018-7.576). Size of fishermen network (OR=0.987, 95% CI=0.977-0.996), crewmembers' knowledge of drug use (OR=7.234, 95% CI=1.430-36.604), and having a captain provide drugs for work (OR=0.134, 95% CI=0.025-0.720) predicted access to clean needles/syringes. Qualitative analyses revealed that occupational culture and social relationships on boats drove drug use and HIV risk.

CONCLUSIONS

While marginalized in broader society, the acceptance of drug use within the fishing community created occupational networks of risk. Fishing boats were spaces of both risk and safety; where drug users participated in the formal economy, but also where HIV risk behaviour occurred. Understanding the interplay between social networks and place is essential for developing HIV prevention and harm reduction policies appropriate for the unique needs of this fishing population.

Network structure and the risk for HIV transmission among rural drug users

Research suggests that structural properties of drug users' social networks can have substantial effects on HIV risk. The purpose of this study was to investigate if the structural properties of Appalachian drug users' risk networks could lend insight into the potential for HIV transmission in this population. Data from 503 drug users recruited through respondent-driven sampling were used to construct a sociometric risk network. Network ties represented relationships in which partners had engaged in unprotected sex and/or shared injection equipment. Compared to 1,000 randomly generated networks, the observed network was found to have a larger main component and exhibit more cohesiveness and centralization than would be expected at random. Thus, the risk network structure in this sample has many structural characteristics shown to be facilitative of HIV transmission. This underscores the importance of primary prevention in this population and prompts further investigation into the epidemiology of HIV in the region.

Social integration and suicide-related ideation from a social network perspective: a longitudinal study among inner-city African Americans

Social network density, as measured by the extent to which network members know each other, was examined to determine whether it is associated with suicide-related ideation and plan approximately 3 years later. Eight hundred and nineteen African Americans were interviewed at Wave 1 (1997-1999) and Wave 4 (2001-2003) of the Self-Help In Eliminating Life-Threatening Diseases (SHIELD) study, a HIV preventive intervention study in Baltimore, MD. Multinomial logistic regression models were used to compare risks of suicide-related ideation and plan at Wave 4 by Wave 1 density. Even after adjusting for baseline sociodemographic characteristics and depressive symptoms, individuals with a lower level of density were three times more likely to report suicide-related ideation and plan in the past year at Wave 4. The findings reinforce the importance of social integration among inner-city African Americans from a social network perspective. Future research should examine the mechanisms associated with this relationship and other social network constructs.

Racial disparities in HIV prevalence and risk behaviors among injection drug users and members of their risk networks

In the United States, racial differences in the prevalence and incidence of HIV infection and AIDS diagnoses are dramatic. These differences are large, have been recognized for nearly 20 years, and are as yet not well investigated. These disparities show no signs of diminishing and, in fact, are widening, particularly among drug users and women. Most observers of the racial disparities in prevalence and incidence of HIV infections and AIDS diagnoses in the United States have concluded that these disparities exist because prevention messages, supplies, and/or interventions do not effectively reach those at greatest risk of infection. In essence, such interpretations suggest that Blacks and Latinos continue to practice more risk behaviors than Whites. There are much data to suggest that this is, in fact, not true. Evidence from 232 'index' injection drug users and 465 of their drug and sexual network members participating in HIV Prevention Trials Network 037 is presented. These data describe lower use and/or access to drug treatment and needle exchange programs by Black injectors. In addition, data indicate the coexistence of increased prevalence of HIV in the networks of uninfected Black drug users and fewer associated risk behaviors in the networks of Black and Latino indices compared with networks of White indices. Understanding racial disparities in HIV is a critical challenge; yet, risk behaviors alone do not explain observed disparities in infection rates.

Social networks and HCV viraemia in anti-HCV-positive rural drug users

Although social networks are known to play an important role in drug-using behaviours associated with hepatitis C virus (HCV) infection, literature on social networks and HCV is inconsistent. This exploratory study examined HCV RNA distribution within a social network of anti-HCV-positive non-medical prescription opioid users (NMPOUs) in rural Appalachia. Participants were tested serologically for HCV RNA, and behavioural, demographic, and network data were collected using interview-administered questionnaires. Multivariate analyses were performed using logistic regression. Behavioural and demographic characteristics did not differ by RNA status. In the multivariate model, recent injecting drug users (IDUs) were more likely to be RNA positive [odds ratio (OR) 4·06, 95% confidence interval (CI) 1·04-15·83], and turnover into an IDU's drug network was significantly protective (OR 0·15, 95% CI 0·03-0·75). This is the first study to date to examine HCV distribution in rural NMPOUs from a network perspective and demonstrates that network characteristics significantly contribute to the epidemiology of HCV in this understudied, high-risk population.

Environmental contamination as a risk factor for intra-household Staphylococcus aureus transmission

BACKGROUND

The household is a recognized community reservoir for Staphylococcus aureus. This study investigated potential risk factors for intra-household S. aureus transmission, including the contribution of environmental contamination.

METHODS

We investigated intra-household S. aureus transmission using a sample of multiple member households from a community-based case-control study examining risk factors for CA-MRSA infection conducted in Northern Manhattan. During a home visit, index subjects completed a questionnaire. All consenting household members were swabbed, as were standardized environmental household items. Swabs were cultured for S. aureus. Positive isolates underwent further molecular characterization. Intra-household transmission was defined as having identical strains among two or more household members. Multiple logistic regression was used to identify independent risk factors for transmission.

RESULTS

We enrolled 291 households: 146 index cases, 145 index controls and 687 of their household contacts. The majority of indexes were Hispanic (85%), low income (74%), and female (67%), with a mean age of 31 (range 1-79). The average size of case and control households was 4 people. S. aureus colonized individuals in 62% of households and contaminated the environment in 54% of households. USA300 was the predominant clinical infection, colonizing and environmental strain. Eighty-one households had evidence of intra-household transmission: 55 (38%) case and 26 (18%) control households (P<.01). Environmental contamination with a colonizing or clinical infection strain (aOR: 5.4 [2.9-10.3] P<.01) and the presence of a child under 5 (aOR: 2.3 [1.2-4.5] P = .02) were independently associated with transmission. In separate multivariable models, environmental contamination was associated with transmission among case (aOR 3.3, p<.01) and control households (aOR 27.2, p<.01).

CONCLUSIONS

Environmental contamination with a colonizing or clinical infection strain was significantly and independently associated with transmission in a large community-based sample. Environmental contamination should be considered when treating S. aureus infections, particularly among households with multiple infected members.

Respondent-driven sampling and the recruitment of people with small injecting networks

Respondent-driven sampling (RDS) is a form of chain-referral sampling, similar to snowball sampling, which was developed to reach hidden populations such as people who inject drugs (PWID). RDS is said to reach members of a hidden population that may not be accessible through other sampling methods. However, less attention has been paid as to whether there are segments of the population that are more likely to be missed by RDS. This study examined the ability of RDS to capture people with small injecting networks. A study of PWID, using RDS, was conducted in 2009 in Sydney, Australia. The size of participants' injecting networks was examined by recruitment chain and wave. Participants' injecting network characteristics were compared to those of participants from a separate pharmacy-based study. A logistic regression analysis was conducted to examine the characteristics independently associated with having small injecting networks, using the combined RDS and pharmacy-based samples. In comparison with the pharmacy-recruited participants, RDS participants were almost 80% less likely to have small injecting networks, after adjusting for other variables. RDS participants were also more likely to have their injecting networks form a larger proportion of those in their social networks, and to have acquaintances as part of their injecting networks. Compared to those with larger injecting networks, individuals with small injecting networks were equally likely to engage in receptive sharing of injecting equipment, but less likely to have had contact with prevention services. These findings suggest that those with small injecting networks are an important group to recruit, and that RDS is less likely to capture these individuals.

Exploring the impact of underage sex work among female sex workers in two Mexico-US border cities

Although sex work and younger age increase HIV vulnerability, empirical data regarding the impacts of underage sex work are lacking. We explored associations between features of the risk environment, sex work, and drug use history, and underage sex work entry among 624 female sex workers (FSWs) in Tijuana and Ciudad Juarez, Mexico. Forty-one percent (n = 253) of women began sex work as minors, among whom HIV and any STI/HIV prevalence were 5.2 and 60.7%. Factors independently associated with increased odds of underage sex work were inhalants as the first drug used, forced first injection, number of drug treatment attempts, and recent receptive syringe sharing. Number of recent condom negotiation attempts with steady partners and depression as a reason for first injecting were negatively associated with underage entry. These results underscore the importance of efforts to prevent underage sex work and the wider factors contributing to HIV risk among vulnerable youth and underage FSWs.

Latent tuberculosis infections in hard-to-reach drug using population-detection, prevention and control

Interferon-gamma release assays (IGRAs) need be evaluated for effectiveness as screening tests for tuberculosis (TB) infection in drug users. These tests have demonstrated improved sensitivity and specificity, but have not been studied in drug users. These one step blood tests are intended to replace the tuberculin skin test (TST), which is difficult to use and requires 48 hour follow-up, so they are expected to be particularly suitable for risk groups, like drug users, in whom follow-up is problematic. Drug users have traditionally been identified as being at increased risk for acquiring TB disease. The results of our pilot study using the TST and simpler and more sensitive interferon-gamma release assays showed that about 45% of current drug users in Houston tested have at least one test positive for latent tuberculosis infection (LTBI). These preliminary data suggest that there is an important reservoir of LTBI in drug using populations, and the risk of progression to active TB disease with other infections is great. However, LTBI in drug using populations has not been studied in depth and deserves further investigation. We need to evaluate the validity of IGRAs for detection of latent TB infection, the factors associated with LTBI, the incidence and risk for developing active TB disease in drug users and the effectiveness of early treatment of LTBI. We believe that using better tuberculosis screening tools will allow us to more accurately measure the prevalence of latent TB infection and incidence of active TB disease in drug using populations and develop more effective TB prevention and treatment interventions in the community.

Understanding subtypes of inner-city drug users with a latent class approach

AIMS

We empirically identified subtypes of inner-city users of heroin and cocaine based on type of drug used and route of administration.

METHOD

The sample was recruited from the communities in Baltimore, MD (SHIELD study) and consisted of 1061 participants who used heroin and or cocaine in the past 6 months on a weekly basis or more. Latent class analysis (LCA) was used to identify subtypes of drug users based on type of drug and route of administration. Logistic regression was used to compare the subtypes on depressive symptoms, injection risk and drug network compositions.

FINDINGS

Inner-city drug users were classified into five subtypes: three subtypes of injection drug users (IDUs) [heroin injecting (n=134; 13%), polydrug and polyroute (n=88, 8%), and heroin and cocaine injecting (n=404, 38%)], and two subtypes with low proportions of IDUs (LIDUs) [heroin snorting (n=275, 26%) and crack smoking (n=160; 14%)]. The polydrug and polyroute subtype had the highest depressive symptoms risk among all subtypes. Injection risk was lowest in the heroin injecting subtype and significantly differed from heroin and cocaine injecting subtype. The IDU subtypes also varied in the drug network compositions. The LIDU subtypes had similar depressive symptoms risk but vastly differed in the drug network compositions.

CONCLUSIONS

Subgroups of inner-city cocaine and heroin users based on type and route of administration differed in their depressive symptoms, injection risk and drug network compositions. Future studies should longitudinally examine factors associated with transitioning across these subtypes to better inform prevention and treatment efforts.

Perceived Behavior of Others and AIDS Risk Behavior Among Heterosexually-Identified Methamphetamine Users

This study used cross-sectional data to examine perceived risk behavior of social network members as a correlate of AIDS risk behavior in a sample of 230 heterosexually-identified, methamphetamine (meth) users. The highest ratings of risk behavior within participants' social networks were associated with meth use and non-use of condoms. Friends received the highest ratings in terms of overall perceived involvement in drug and sexual risk behaviors. In a multivariate analysis, perceived risk behavior of others, social norms, and attitudes toward AIDS preventive behaviors were significantly associated with intentions to always use condoms. Strategies for addressing negative social influences in the context of sexual risk reduction interventions are described.

Unsafe injection and sexual risk behavior among injecting drug users in Georgia

Injection drug users (IDUs) are at risk for acquiring human immunodeficiency virus (HIV) through parenteral and sexual transmission. In this paper, we describe the prevalence and correlates of unsafe drug injecting and sexual behaviors among IDUs recruited across five cities in Georgia in 2009. IDUs were administered a questionnaire collecting information on demographics, drug use, sexual behaviors, and HIV testing behaviors. Correlates of risky injecting and sexual behaviors were determined using logistic regression. Of 1,127 IDUs, the majority (98.7%) were men, and the median duration of injecting drugs was 7 years. Unsafe injecting behavior at last injection was reported by 51.9% of IDUs, while 16.8% reported both unsafe injecting behavior and not using condoms with last occasional and/or commercial partner. In the multivariate analysis, independent correlates of unsafe injecting behavior at last injection were types of drugs injected [p = 0.0096; (for ephedrine, adjusted odds ratio (aOR) = 7.38; 95% CI, 1.50-36.26)] and not using condoms at last commercial sex (aOR = 2.29, 1.22-4.32). The following variables were significantly associated with unsafe injecting behavior at last injection and not using condoms at last sex with commercial and/or occasional partners in the multivariate analysis: marital status [p = 0.0002; (for divorced, widowed, and separated aOR = 2.62, 1.62-4.25; for single aOR = 1.61, 1.08-2.39)], being a member of a regular injecting group (aOR = 0.62, 0.44-0.88), types of drugs injected in the past month [p = 0.0024; (for buprenorphine aOR = 0.34, 0.18-0.63)], city of residence (p = 0.0083), and not receiving information on HIV (aOR = 1.82, 1.07-3.09). Though only ephedrine was injected by a smaller number of IDUs (9.1%), the vast majority of these (81.4%) reported unsafe injecting practices at last injection. High prevalence of unsafe injecting behaviors and diverse and at-risk sexual partnerships highlight the need to implement complex and targeted HIV interventions among IDUs in Georgia.

Sexual networks and housing stability

Unstable housing is related to a range of health problems including substance abuse, poor mental health, and HIV. Little is known about how sexual partners' attributes influence access to resources such as housing. The purpose of the present study was to examine the relationship between sexual network characteristics and improvements in housing situation among a sample of drug users using a longitudinal design. Size of one's sex network was not associated with housing change. However, having a main partner and having a sex partner who lent money was associated with moving from a homeless state at baseline to being housed at follow-up. Also, having a sex partner who was a drug user was associated with decrease in the odds of improving one's housing situation.

Drug network characteristics and HIV risk among injection drug users in Russia: the roles of trust, size, and stability

We investigated the influence of drug network characteristics including trust, size, and stability on HIV risk behaviors and HIV testing among injection drug users (IDUs) in St. Petersburg, Russia. Overall, male and female IDUs who reported having high levels of trust in their drug networks were significantly more likely to share syringes than those with lower levels of trust (OR [95% CI]) 2.87 [1.06, 7.81] and 4.89 [1.05, 21.94], respectively). Male and female IDUs in larger drug networks were more likely to share syringes than those in smaller networks (4.21 [1.54, 11.51] and 4.80 [1.20, 19.94], respectively). Characteristics that were significantly associated with not having been HIV tested included drug network instability among men and larger network size among women. High trust, large size, and instability were positively and significantly associated with syringe sharing and not having been HIV tested. Effectiveness of interventions in Russia to reduce the risk of HIV infection may be enhanced if network characteristics are addressed.

Crossing over: drug network characteristics and injection risk along the China-Myanmar border

Border areas are important locations for understanding HIV transmission. This study examines individual and network correlates of border crossing and equipment sharing among methadone maintenance clients in Ruili City, a Chinese city on the Myanmar border. Data are from 298 clients enrolled in the Ruili Methadone Treatment Center. Clients were interviewed about drug use, HIV/AIDS knowledge, treatment motivation, and their social networks. Multinomial and logistic regression analysis were performed. Thirty percent of clients reported injecting in Myanmar. Compared to drug networks that usually inject in China, networks that inject equally in both places (border crossing) are more likely to share equipment. The association between HIV positive status and border-crossing was marginally significant and robust. Results indicate some added degree of risk among clients and drug networks who border-cross to use drugs. More research is needed to understand this phenomenon.