Individual, social, and environmental factors associated with initiating methamphetamine injection: implications for drug use and HIV prevention strategies

Latent polydrug use patterns and the provision of injection initiation assistance among people who inject drugs in three North American settings

INTRODUCTION

We sought to identify latent profiles of polysubstance use patterns among people who inject drugs in three distinct North American settings, and then determine whether profile membership was associated with providing injection initiation assistance to injection-naïve persons.

METHODS

Cross-sectional data from three linked cohorts in Vancouver, Canada; Tijuana, Mexico; and San Diego, USA were used to conduct separate latent profile analyses based on recent (i.e., past 6 months) injection and non-injection drug use frequency. We then assessed the association between polysubstance use patterns and recent injection initiation assistance provision using logistic regression analyses.

RESULTS

A 6-class model for Vancouver participants, a 4-class model for Tijuana participants and a 4-class model for San Diego participants were selected based on statistical indices of fit and interpretability. In all settings, at least one profile included high-frequency polysubstance use of crystal methamphetamine and heroin. In Vancouver, several profiles were associated with a greater likelihood of providing recent injection initiation assistance compared to the referent profile (low-frequency use of all drugs) in unadjusted and adjusted analyses, however, the inclusion of latent profile membership in the multivariable model did not significantly improve model fit.

DISCUSSION AND CONCLUSIONS

We identified commonalities and differences in polysubstance use patterns among people who inject drugs in three settings disproportionately impacted by injection drug use. Our results also suggest that other factors may be of greater priority when tailoring interventions to reduce the incidence of injection initiation. These findings can aid in efforts to identify and support specific higher-risk subpopulations of people who inject drugs.

Associations between prescription stimulant use as prescribed, nonmedical use, and illicit stimulant use among adults evaluated for substance use treatment, 2017-2021

Background

Limited data exist on risk factors for illicit stimulant use, including associations between prescription stimulant use/nonmedical use (NMU) and illicit stimulant use.

Methods

We used 2017-2021 data from adults assessed for substance use disorder (SUD) treatment using the National Addictions Vigilance Intervention and Prevention Program Addiction Severity Index-Multimedia Version® tool. Multivariable Poisson regression models analyzed associations between past 30-day prescription stimulant use as prescribed or NMU and past 30-day illicit stimulant use. Separate models examined past 30-day illicit stimulant, methamphetamine, and cocaine use. We explored problem severity across seven biopsychosocial domains (e.g., drug, psychiatric, family) by past 30-day prescription stimulant use/NMU and illicit stimulant use.

Results

Among 218,981 assessments, 1.8% reported prescription stimulant NMU; 1.6% reported use as prescribed. Past 30-day prescription stimulant NMU (vs. no use) was associated with past 30-day illicit stimulant use (adjusted prevalence ratio [aPR] [95% CI]: 2.67 [2.59, 2.75]), methamphetamine use (aPR: 2.81 [2.71, 2.92]), and cocaine use (aPR: 3.53 [3.33, 3.74]). Prescription stimulant use as prescribed (vs. no use) was associated with lower prevalence of past 30-day illicit stimulant use. Assessments reporting prescription stimulant NMU (vs. no use, or use as prescribed) appeared more likely to have moderate-to-extreme problem scores across biopsychosocial domains, indicating greater need for treatment or assistance. Assessments reporting prescription stimulant use as prescribed or NMU frequently reported opioids, alcohol, or other substances as their primary substance problem.

Conclusions

Adults using illicit stimulants/nonmedically using prescription stimulants may benefit from care addressing polysubstance use, mental health, social, and recovery support services.

The Global Distribution and Epidemiology of Psychoactive Substance Use and Injection Drug Use Among Street-Involved Children and Youth: A Meta-Analysis

Background: Globally, street-involved children and youth (SICY) who work and live on/of the streets are at higher risk of increased psychoactive substances and injecting drug use. Objectives: The present study aimed to identify the prevalence, distribution, sociodemographic factors, and risk-taking behaviors associated with psychoactive substances and injecting drug use among SICY. Methods: Studies in English published from December 1 1985 to July 1 2022, were searched for on PubMed, Scopus, Cochrane, and Web of Science to identify primary studies on psychoactive substances and injecting drug use among SICY. The pooled-prevalence estimates were obtained using a robust fixed-effects model. Results: The most commonly reported life-time and current psychoactive substance was tobacco followed by cannabis, LSD/ecstasy, cocaine, methamphetamine, heroin and injection drug use. The results showed that life-time and current prevalence of methamphetamine and cannabis use, as well as life-time prevalence of cocaine, LSD/ecstasy, heroin, tobacco, and injecting drug use increased as age rose while current prevalence of cocaine and tobacco use decreased as age rose. SICY who were male, homeless, had parents who had died, had history of substance use among family members or best friends, had experienced violence, had casual sex partners, had a history of working in the sex trade, and had unprotected sex were all related to psychoactive substance use and injecting drug use. Conclusions: Research examining this population suffers from lack of studies, therefore, improving the knowledge for interventions aimed at reducing risk behaviors, particularly those related to the transmission of sexually transmitted infections such as HIV is of great importance.

Trends and distinct profiles of persons who inject drugs in the United States, 2015-2019

Drug injection represents a major health problem in the US, with severe health consequences including the transmission of blood-borne infections. An examination of the most recent trends in drug injection is warranted by the fast-evolving drug epidemic and recent policy changes such as the federal funding ban on needle exchange programs. This research examines current drug injection trends, patterns, and socioeconomic and behavioral profiles of people who inject drugs (PWID). Data were derived from the 2002 to 2019 National Survey on Drug Use and Health (NSDUH). After examining the annual prevalence of drug injection since 2002, a latent class analysis was conducted to identify drug injection and other substance misuse patterns among PWID using the latest (2015-2019) NSDUH datasets. Associations between class membership and behavioral health comorbidities and treatment receipt were also assessed. The drug injection prevalence among US adults aged 18-64 increased from 0.21% in 2002/2004 to 0.36% in 2017/2019. Three distinctive groups were identified: the heroin injection group (45.2%), the methamphetamine injection group (28.0%), and the multi-drug injection group (26.8%). The methamphetamine injection group reported greater risks of experiencing serious psychological distress, suicidality, and limited substance use treatment. Special attention is needed for those who primarily injected methamphetamine. Programs to promote harm reduction and increase access to addiction treatment need to be expanded in at-risk communities while accounting for their distinct socioeconomic and drug use/misuse profiles.

Loneliness, Risky Beliefs and Intentions about Practicing Safer Sex among Methamphetamine Dependent Individuals

BACKGROUND

Methamphetamine use is a known predictor of riskier sexual behaviors, which can have important public health implications (e.g., HIV-transmission risk). Loneliness also is associated with riskier sexual behaviors, though the relationship between loneliness and beliefs and/or intentions to practice safer sex has not been examined among people dependent on methamphetamine.

MATERIALS AND METHODS

Individuals who met DSM-IV criteria for lifetime methamphetamine dependence and current (≤ 18-months) methamphetamine abuse or dependence (METH+ n = 56) were compared to those without severity and recency of methamphetamine use (METH- n = 59). These groups did not differ on social network size or proportion of people with HIV (∼58% HIV+). Participants completed the NIH Toolbox Loneliness Scale and the Sexual Risks Scale's "Norms" and "Intentions" subscales.

RESULTS

METH+ individuals were significantly lonelier than METH- controls (t(113) = 2.45, p = .02). Methamphetamine dependence remained significantly associated with greater loneliness, after controlling for HIV status and other relevant covariates (e.g., neurocognitive impairment, history of mood disorder, social network size; F = 3.70, Adjusted R² = 0.18, p = .0009). Loneliness, above and beyond the aforementioned covariates, was significantly associated with riskier beliefs and intentions to practice safer sex among METH+, but not METH-, individuals (β = 2.92, p = .02).

CONCLUSIONS

Loneliness is prevalent among individuals dependent on methamphetamine, and is uniquely associated with riskier beliefs and intentions regarding practicing safer sex. Findings may aid in identifying individuals at-risk of engaging in riskier sexual behaviors and guide risk prevention strategies.

Care-engaged individuals with polysubstance use in Northeastern US are undertreated for methamphetamine use disorder: a retrospective cohort study

BACKGROUND

Stimulant use has increased across the US, with concomitant opioid and methamphetamine use doubling between 2011 and 2017. Shifting patterns of polysubstance use have led to rising psychostimulant-involved deaths. While it is known that individuals who use methamphetamine require greater access to treatment, there is still little known about methamphetamine use and treatment among individuals who are already engaged in outpatient substance use treatment.

OBJECTIVES

To characterize care-engaged individuals who use methamphetamine to guide harm reduction and treatment strategies.

METHODS

Retrospective cohort study of individuals at a large academic medical center in Massachusetts with ≥ 2 positive methamphetamine oral fluid toxicology tests between August 2019 and January 2020. We performed descriptive analysis of sociodemographic, medical, and drug use characteristics and a comparative analysis of injection methamphetamine use versus other routes of use.

RESULTS

Included were 71 individuals [56 male (80%), 66 non-Hispanic white (94%), median age 36 (IQR 30-42)]. Nearly all had opioid (94%) and stimulant use disorder (92%). Most had (93%) or were (83%) being treated with medications for opioid use disorder, but few received pharmacologic treatment for methamphetamine use disorder (24%). None received contingency management treatment. People who inject methamphetamine (68%) were more likely to have a history of overdose (91% vs. 70%; p = 0.02), have HCV (94% vs. 52%; p < 0.01), use fentanyl (93% vs. 65%; p = 0.02), and engage in sex work (19% vs. 0%; p = 0.03) compared to those who used via other routes. Both groups had prevalent homelessness (88% vs. 73%; p = 0.15), incarceration (81% vs. 64%; p = 0.11), depression (94% vs. 87%; p = 0.34), and bacteremia (27% vs. 22%; p = 0.63).

CONCLUSIONS

Individuals in our study had high prevalence of polysubstance use, particularly concomitant methamphetamine and opioid use. Individuals who were well connected to substance use treatment for their opioid use were still likely to be undertreated for their methamphetamine use disorder and would benefit from greater access to contingency management treatment, harm reduction resources, and resources to address adverse social determinants of health.

Adverse childhood experiences and stimulant use disorders among adults in the United States

Recent data indicate a resurgence of stimulant use and harms in the United States; thus, there is a need to identify risk factors to inform development of effective prevention strategies. Prior research suggests adverse childhood experiences (ACEs) are common among individuals using stimulants and may be an important target for prevention. National Epidemiological Survey on Alcohol and Related Conditions was used to estimate prevalence of ACEs among U.S. adults using amphetamine-type stimulants (ATS), cocaine, or both. Multivariable logistic regression examined associations between ACEs and stimulant use and use disorders. Among adults reporting lifetime ATS use, 22.1% had ≥4 ACEs, 24.9% had 2-3 ACEs, 22.4% had 1 ACE, 30.6% reported no ACEs. Among adults with lifetime ATS use disorder, 29.3% reported ≥4 ACEs, 28.7% reported 2-3 ACEs, 21.6% reported 1 ACE, and 20.4% reported no ACEs. Multivariable logistic regression found a significant relationship between number of ACEs and stimulant use and use disorders. In conclusion, we found a strong relationship between increasing ACE exposures and stimulant use and use disorders. Advancing comprehensive strategies to prevent ACEs and treating underlying trauma among those using stimulants holds great promise to reduce stimulant use and its health and social consequences in the United States.

'Resurgent', 'twin' or 'silent' epidemic? A select data overview and observations on increasing psycho-stimulant use and harms in North America

In the early 2000s, increasing prevalence of psycho-stimulant (e.g., crack/cocaine, methamphetamine) use and related harms, including severe adverse health outcomes, was observed among - mostly marginalized - populations of persons using illicit drugs in North America, underscoring an urgent need for interventions options towards improved prevention and treatment. By about 2010, however, the 'opioid crisis', featuring unprecedented use and public health burden, had accelerated into full force in North America, largely muting attention to the psycho-stimulant issue until recently. Recent surveillance data on drug use and related mortality/morbidity from the present decade has documented a marked resurgence of psycho-stimulant use and harms especially in at-risk populations, commonly in direct combination with opioids, across North America, resulting in a 'twin epidemic' comprised of opioids and psycho-stimulants We briefly review select epidemiological data indicators for these developments from the United States and Canada; in the latter jurisdiction, related evidence has been less prevalent and systematic but corroborating the same trends. Evidently, the (widely ongoing) focus on the 'opioid epidemic' as a 'mono-type' drug problem has become an anachronism that requires urgent and appropriate correction. We then briefly consider existing, evidence-based options for - prevention and treatment - interventions targeting psycho-stimulant use and harms, which are substantially more limited and/or less efficacious than those available for problematic opioid use, while presenting major gaps and challenges. The observed resurgence of psycho-stimulants may, indirectly, relate to recent efforts towards curtailing (medical) opioid availability, thereby accelerating demand and supply for both illicit opioids and psycho-stimulants. The presently unfolding 'twin epidemic' of opioids and psycho-stimulants, combined with limited intervention resources, presents an acute challenge for public health and may crucially undermine actively extensive efforts to reduce opioid-related health harms in North America.

Residential eviction predicts initiation of or relapse into crystal methamphetamine use among people who inject drugs: a prospective cohort study

Reports of increasing methamphetamine use among vulnerable populations may be attributed in part to the adaptive use of stimulants in response to the loss of stable housing through residential eviction. We employed multivariable recurrent event extended Cox regression to examine the independent association between recent evictions and initiation of or relapse into crystal methamphetamine use among people who inject drugs in Vancouver, Canada enrolled in two prospective cohort studies. In a multivariable analysis, eviction remained independently associated with methamphetamine initiation or relapse (adjusted hazard ratio = 1.90; 95% confidence interval: 1.31-2.75). Findings demonstrate the need to secure tenancies for drug-using populations to reduce harms.

Factors associated with time between using a drug and injection initiation among people who inject drugs in Kermanshah, Iran

Background The transition from non-injection to injection drug use dramatically increases the risk of transmitting HIV and other blood borne infections including hepatitis B virus (HBV) and hepatitis C virus (HCV). The aim of this study was to explore factors associated with the transition from first illicit drug use to first injection among drug users. Methods Using snowball sampling and convenience sampling through needle and syringe programmes (NSPs), we recruited 500 people who inject drugs (PWID) in Kermanshah, between September and December 2014. Trained interviewers collected data on socio-demographic characteristics, HIV testing and drug-related risk behaviors over the last month prior to interview using a structured questionnaire. Our main outcome variable was first illicit drug use to first injection (TIJ). TIJ was calculated by subtracting age at first drug injection from age of first illicit drug use. Results Overall, the average age at first drug use and injection were 21.4 [standard deviation (SD 5.6)] and 22.8 (SD 8.9), respectively. The average duration of injection was 6.0 (SD 4.6) years. Overall, the mean of TIJ for participants was 1.4 (IQR = 2, 4) years. Age of first injecting drug use negatively correlated with TIJ (R2 = 0.219, p = 0.001). Education level and socioeconomic status (SES), and negatively correlated with TIJ. Conclusion Some demographic factors and drug use characteristics including educational level, SES, knowledge of HIV status, age of initiating drug use, being a poly drug user and using methamphetamine were predictors of the time to transition.

Differences in risk behaviours and HIV status between primary amphetamines and opioid injectors in Estonia and Russia

BACKGROUND AND OBJECTIVE

People who inject drugs (PWID) account for over half of new HIV infections in Eastern Europe and central Asia, where opioids continue to be the dominant illicit drugs injected. Stimulants including amphetamines (ATS) have been associated with HIV infection risk in several settings. We sought to examine whether primary ATS injection was associated with greater HIV risk, compared to opioid injection in two European locales with significant HIV epidemics.

METHODS

PWID in Kohtla-Järve and St. Petersburg were recruited using respondent-driven sampling in 2012-2013. Survey data on demographic characteristics, service use, injecting and sexual risk behaviours and HIV-status (and HCV in Kohtla-Järve) were compared between primary opioid and ATS injectors using logistic regression models.

RESULTS

Of 591 injectors recruited in Kohtla-Järve and 811 in St. Petersburg, 195 (33%) and 27 (4%) primarily injected ATS in each city. In both cities, ATS injectors were younger than opioid injectors, initiated injection later, injected less frequently and were more likely to have been paid for sex. In both cities, PWID had high levels of multiple sex partners. In Kohtla-Järve, ATS-injectors had lower odds of back-loading and greater odds of polydrug use than opioid-injectors. In St. Petersburg, where over half of PWID reported unsafe sharing practices, ATS-injectors were less likely to report these practices. ATS-injection was negatively associated with being HIV positive in Kohtla-Järve (aOR = 0.6; 95%CI: 0.5-0.8) and St. Petersburg (aOR = 0.3; 95%CI: 0.1-0.7). ATS-injection was negatively associated with HCV-reactivity in Kohtla-Järve (aOR = 0.5; 95%CI: 0.3-0.6).

CONCLUSIONS

In both locations, primary ATS injection was associated with lower injecting risk behaviours, lower odds of HIV and being paid for sex compared to opioid injection. Interventions targeting the characteristics and needs of ATS injectors are needed to increase contact with services and reduce sexual and injecting risk. Harm reduction services, including sexual risk reduction, need to be expanded for all PWID in St. Petersburg.

Relationship between a network's indicators and basic factors with high-risk behavior of injection among injecting drug users (IDU) via the multiple membership multilevel model

Background

Among various methods and types of drug abuse, injection receives a great deal of importance because of its related dangerous behavior and health consequences. It seemed that some of the network’s indicators affect dangerous behavior of injection.

Objective

To determine the relationship between a network’s indicators and basic factors with high-risk behavior of injection among injecting drug users (IDU) via the multiple memberships multilevel model.

Methods

In this cross-sectional study, the data related to 147 IDUs in Kerman province, who were interviewed from October 2013 through March 2014, were used, and these addicts were chosen for interview from specific resorts used for common injection. In this study, for analyzing data, multiple membership multilevel model and MLwiN 2.02 software were used.

Results

In this study, the mean age of people, who were mostly men, was 37.2±9.02. Based on the result, it becomes obvious that variables of in-degree with OR=1.49 (p=0.006) and the whole number of people related to the person with OR=1.18 (p=0.003) influences the high-risk behavior of injection. Also, none of the demographic variables influenced the high-risk behavior of injection.

Conclusion

Totally based on the results of this study, one can find a suitable method in the social network of IDUs in order to create essential strategies, reducing the risk throughout the country. In addition, in minimum time with fewer expenses, aggravation of dangerous behavior especially high-risk behavior of injection can be prevented.

Polysubstance use in treatment seekers who inject amphetamine: Drug use profiles, injecting practices and quality of life

BACKGROUND

The injection of amphetamine is becoming increasingly common. However, there has been a lack of research examining people who inject amphetamine as the primary drug of use, limiting the potential to ensure services address the unique needs of this group. The current study used latent class analysis to identify classes of polydrug use among people who report injecting amphetamine during the past 12months. It also examined differences between classes and drug use patterns, injecting practices, quality of life and psychological distress.

METHODS

Participants who were attending non-government specialist alcohol and other drug treatment across New South Wales, Australia and had identified amphetamine as their principle drug of concern and reported injecting amphetamine in the previous 12months were included in the current study (N=827). Latent class analysis was performed to identify polydrug profiles of participants.

RESULTS

The large majority of people in the current study (85%) demonstrated low probability of heroin or other opiate use. Three distinct classes of polydrug use were identified: (1) Low-polydrug (n=491), (2) Opiates-polydrug (n=123), and (3) Alcohol-polydrug (n=213). There was a trend for the Low-polydrug class to demonstrate better functioning and safer injecting practices than the Opiates-polydrug and Alcohol-polydrug classes.

CONCLUSION

The results suggest that the majority of people accessing treatment who inject amphetamine as their primary drug of choice have a low probability of heroin or other opiate use. It is important that future research consider whether traditional harm minimisation strategies are appropriate for people who primarily inject amphetamine.

Patterns of HIV Risks and Related Factors among People Who Inject Drugs in Kermanshah, Iran: A Latent Class Analysis

The objective of this study was to explore patterns of drug use and sexual risk behaviors among people who inject drugs (PWID) in Iran. We surveyed 500 PWID in Kermanshah concerning demographic characteristics, sexual risk behaviors, and drug-related risk behaviors in the month prior to study. We used latent class analysis (LCA) to establish a baseline model of risk profiles and to identify the optimal number of latent classes, and we used ordinal regression to identify factors associated with class membership. Three classes of multiple HIV risk were identified. The probability of membership in the high-risk class was 0.33, compared to 0.26 and 0.40 for the low- and moderate-risk classes, respectively. Compared to members in the lowest-risk class (reference group), the highest-risk class members had higher odds of being homeless (OR = 4.5, CI: 1.44-8.22; p = 0.001) in the past 12 months. Members of the high-risk class had lower odds of regularly visiting a needle and syringe exchange program as compared to the lowest-risk class members (AOR = 0.42, CI: 0.2-0.81; p = 0.01). Findings show the sexual and drug-related HIV risk clusters among PWID in Iran, and emphasize the importance of developing targeted prevention and harm reduction programs for all domains of risk behaviors, both sexual and drug use related.

Initiation into prescription opioid injection and associated trends in heroin use among people who use illicit drugs

OBJECTIVES

Prescription opioid (PO) injection among people who use illicit drugs (PWUD) is an ongoing concern, yet little is known about drug use trajectories associated with initiating PO injection, including potential associations with heroin use. This study aimed to identify predictors of PO injection initiation among PWUD, and examine trends in heroin use before and after initiating PO injection.

METHODS

Data were merged from three cohorts of PWUD recruited between September 2005 and November 2015. Predictors of PO injection initiation were identified using extended Cox regression models. Trends in heroin use pre- and post-initiation were examined with McNemar's test and compared to matched controls with linear growth curve models.

RESULTS

Among 1580 participants, 247 initiated PO injection yielding an incidence density of 3.9 (95% Confidence Interval [CI]: 3.4-4.4) per 100 person-years. In a multivariable analysis, independent predictors of PO injection initiation included heroin injection (Adjusted Hazard Ratio [AHR]=4.39, 95% CI: 3.24-5.95) and non-injection PO use (AHR=1.99, 95% CI: 1.25-3.17). In a sub-analysis, compared to matched controls, PO injection corresponded with elevated heroin use post-initiation (p≤0.05).

DISCUSSION

In this study, heroin use and non-injection PO use strongly predicted PO injection initiation. Those who initiated PO injecting had elevated heroin use patterns post-initiation compared to controls. These findings suggest that transitioning to PO injection does not appear to be a substitute for heroin use among PWUD. These findings highlight the importance of addressing PO injection in harm reduction and treatment settings.

The role of living context in prescription opioid injection and the associated risk of hepatitis C infection

BACKGROUND AND AIMS

Prescription opioid injection (POI) is a leading risk factor for hepatitis C virus (HCV). Residential context relates to high‐risk injection behaviour. This study assessed whether residence in the inner city (versus surrounding areas in Montréal Island) modified the effects of correlates of POI or the relationship between POI and HCV incidence.

DESIGN

Prospective cohort study.

SETTING

Montréal, Canada.

PARTICIPANTS

A total of 854 people who inject drugs (18% female, 25% age < 30 years), living on Montréal Island, were interviewed every 3–6 months from 2004 to 2012.

MEASUREMENTS

Study visits included HCV antibody testing and an interviewer‐administered questionnaire. Generalized estimating equations were used to test whether place of residence modified the effects of correlates of POI. Cox regression was used to test whether place of residence modified the relationship between POI and HCV incidence.

FINDINGS

At baseline, inner‐city participants were more likely to report POI in the past month (40 versus 25%, P < 0.001). The association between POI and heroin injection, syringe sharing and sharing of injecting equipment varied according to place of residence and was greater in the inner city. The hazard of HCV infection associated with POI was greater among inner‐city participants compared to those in the surrounding areas [adjusted hazard ratio (HR) = 3.38, 95% confidence interval (CI) = 1.88–6.07 versus HR = 1.26, 95% CI = 0.65–2.42, P = 0.025].

CONCLUSIONS

Among people who inject prescription opioids in Montréal, Canada, those who live in inner‐city areas are more likely to engage in injecting‐related risk behaviours and have a higher risk of hepatitis C virus infection than those who live in the suburbs.

Barriers to Viral Suppression Among Female Sex Workers: Role of Structural and Intimate Partner Dynamics

OBJECTIVE

Despite global evidence that sex workers (SWs) are disproportionately impacted by HIV, data on HIV treatment outcomes among SWs living with HIV remains sparse. This study examined the correlates of undetectable plasma viral load (pVL) among street- and off-street SWs living with HIV and on antiretroviral therapy (ART) in Metro Vancouver, Canada.

METHODS

Analyses drew on data (2010-2014) from a longitudinal cohort of SWs (An Evaluation of Sex Workers Health Access) and confidential linkages with the Drug Treatment Program (DTP) data on ART dispensation and outcomes. Bivariate and multivariable generalized linear mixed-effects models were used to identify longitudinal correlates of undetectable pVL (<50 copies/mL).

RESULTS

Of the 72 SWs living with HIV who had ever used ART, 38.9% had an undetectable pVL at baseline. Although 84.7% had undetectable pVL at least once over the study period, 18.1% exhibited sustained undetectable pVL. In multivariable generalized linear mixed-effects model analyses, ≥95% pharmacy refill adherence (adjusted odds ratio (AOR) = 4.21; 95% confidence interval (CI) 2.16 to 8.19) and length of time since diagnosis (AOR = 1.06; 95% CI: 1.00 to 1.13) were positively correlated with undetectable pVL. Having an intimate male partner (AOR = 0.35; 95% CI: 0.16 to 0.78) and being homelessness were negatively correlated with undetectable pVL (AOR = 0.22; 95% CI: 0.10 to 0.47).

DISCUSSION/CONCLUSIONS

There is a need to more closely consider the social and structural contexts that shape SWs' experiences on ART and impact treatment outcomes, including the gendered power dynamics within intimate partnerships. Future research on HIV care among SWs is urgently needed, alongside structural and community-led interventions to support SWs' access to and retention in care.

Sociometric network structure and its association with methamphetamine use norms among homeless youth

Homeless youths' social networks are consistently linked with their substance use. Social networks influence behavior through several mechanisms, especially social norms. This study used sociometric analyses to understand whether social norms of drug use behaviors are clustered in network structures and whether these perceived norms (descriptive and injunctive) influence youths' drug use behaviors. An event-based approach was used to delineate boundaries of the two sociometric networks of homeless youth, one in Los Angeles, CA (n = 160) and the other in Santa Monica, CA (n = 130). Network characteristics included centrality (i.e., popularity) and cohesiveness (location in dense subnetworks). The primary outcome was recent methamphetamine use. Results revealed that both descriptive and injunctive norms influenced methamphetamine use. Network cohesion was found to be associated with perception of both descriptive and injunctive norms in both networks, however in opposite directions. Network interventions therefore might be effective if designed to capitalize on social influence that naturally occurs in cohesive parts of networks.

Injecting and Sexual Networks and Sociodemographic Factors and Dual HIV Risk among People Who Inject Drugs: A Cross-sectional Study in Kermanshah Province, Iran

BACKGROUND

Few studies suggest that social network factors, including size of sexual network may associate with drug-related and sexual high-risk behaviors. The objective of this study is to investigate injecting and sexual networks and sociodemographic factors that might be associated with dual HIV risk (DHR) among people who inject drug (PWID).

METHODS

The data from a cross-sectional study of 455 PWID that were recruited through peer-referral sampling were used in this study. The data were collected using a structured questionnaire consisted of modules on sociodemographic characteristics, sexual and injection-related risk behaviors during 12 months before the interview. DHR was defined as engaged in both using a syringe previously used by other PWIDs and unprotected sex during last 12 months. Data analysis was performed with descriptive and logistic regression. In final model, we considered variables with P < 0.500 as statistically significant. Finally, reported adjusted odds ratio (AOR) and confidence interval (95% CI) for variables that were significant in the final model.

FINDINGS

A total of 455 men who injected drugs participated in this study. The mean age ± standard deviation (SD) was 33.2 ± 7.3 (range 19-58) years. Overall, the prevalence of DHR In the last 12 months, 38% (95% CI: 18.3-51.2%). Multivariate model showed that regular visit to needle, syringe programs (NSPs) reduced odd of HDR to 50% when adjusted for other covariates, but still remained statistically significant (P < 0.050). The odds of reporting DHR was significantly higher in those ≥ 2 sex partners and injection partner (P < 0.010). Odds of DHR was higher (AOR: 2.3) among participants who had more than 2 injection per day but was not statistically significant (P > 0.050).

CONCLUSION

DHR was common in PWID in Kermanshah, Iran. Having multiple injecting and sexual partners increased the odds of engaging in dual risk behaviors, but regular visit of NSPs can reduce the DHR among PWID.

A qualitative study of methamphetamine initiation in Cape Town, South Africa

BACKGROUND

Despite a significant rise in methamphetamine use in low- and middle-income countries, there has been little empirical examination of the factors that contribute to individuals' initiation of methamphetamine use in these settings. The goal of this study was to qualitatively examine factors associated with methamphetamine initiation in South Africa.

METHODS

In-depth interviews were conducted with 30 active methamphetamine users (13 women and 17 men) in Cape Town, South Africa. Interviews included narrative descriptions of the circumstances surrounding methamphetamine initiation. Interviews were audio recorded, transcribed, and translated. Transcripts were analyzed with document memos, data display matrices, and a constant comparison technique to identify themes.

RESULTS

On average, participants began regularly using methamphetamine around age 21 and had used for seven years. Four major themes emerged related to the initiation of methamphetamine use. The prevalence of methamphetamine users and distributors made the drug convenient and highly accessible to first time users. Methamphetamine has increased in popularity and is considered "trendy", which contributes to social pressure from friends, and less often, family members to initiate use. Initiation is further fueled by a lack of opportunities for recreation and employment, which leads to boredom and curiosity about the rumored positive effects of the drug. Young people also turn to methamphetamine use and distribution through gang membership as an attempt to generate income in impoverished communities with limited economic opportunities. Finally, participants described initiating methamphetamine as a means of coping with the cumulative stress and psychological burden provoked by the high rates of violence and crime in areas of Cape Town.

CONCLUSION

The findings highlight the complex nature of methamphetamine initiation in low- and middle-income countries like South Africa. There is a need for community-level interventions to address the availability and perceived normality of methamphetamine use, and to provide young people opportunities for recreation. On an individual level, addressing mental health and misconceptions about the dangers and benefits of methamphetamine could ameliorate willingness for initiation. Potential points of intervention include mass media campaigns and school-based interventions to raise awareness of the physical and social impacts of methamphetamine, and structural interventions to create safer neighborhoods, provide opportunities for employment and recreation, and expand mental health services to improve emotional health and coping skills.

Transition to injecting drug use in Iran: A systematic review of qualitative and quantitative evidence

BACKGROUND

Injection drug use, a behavior associated with significant adverse health effects, has been increasing over the past decade in Iran. This study aims to systematically review the epidemiological and qualitative evidence on factors that facilitate or protect the transition to injection drug use in Iran.

METHODS

We conducted electronic searches in five international (Medline, Web of Science, EMBASE, CINAHL, PsycINFO), one regional (IMEMR) and three Iranian (Iranmedex, Iranpsych, IranDoc) databases, as well as contacting experts in the field. Two trained researchers screened documents to identify relevant studies and independently dual-extracted data following pre-specified protocol. We applied principles of thematic analysis for qualitative data and applied a random effect meta-analysis model for age of first injection.

RESULTS

A total of 38 documents from 31 studies met eligibility criteria, from which more than 50% were implemented from 2006 to 2008. The weighted mean age of first injection was 25.8 (95% Confidence Interval: 25.3-26.2). Between 1998 and 2011, the age of first injection was relatively stable. Overall, drug users had used drugs for 6-7 years before they started injection use. Heroin was the first drug of injection in the majority of the cases. We identified factors influencing the initiation of or transition to injection use at various levels, including: (1) individual (pleasure-seeking behavior, curiosity and development of drug dependency commonly reported), (2) social and environmental (role of peer drug users in the first injection use, the economic efficiency associated with injections and the wide availability of injectable form of drugs in the market).

CONCLUSION

Harm reduction policies in Iran have almost exclusively focused on drug injectors in Iran. However, given the extent of the non-injection drug use epidemic, evidence from this study can provide insight on points of interventions for the prevention of the transition to injection use.

Illicit drug use and harms, and related interventions and policy in Canada: A narrative review of select key indicators and developments since 2000

BACKGROUND

By the year 2000, Canada faced high levels of illicit drug use and related harms. Simultaneously, a fundamental tension had raisen between continuing a mainly repression-based versus shifting to a more health-oriented drug policy approach. Despite a wealth of new data and numerous individual studies that have emerged since then, no comprehensive review of key indicators and developments of illicit drug use/harm epidemiology, interventions and law/policy exist; this paper seeks to fill this gap.

METHODS

We searched and reviewed journal publications, as well as key reports, government publications, surveys, etc. reporting on data and information since 2000. Relevant data were selected and extracted for review inclusion, and subsequently grouped and narratively summarized in major topical sub-theme categories.

RESULTS

Cannabis use has remained the principal form of illicit drug use; prescription opioid misuse has arisen as a new and extensive phenomenon. While new drug-related blood-borne-virus transmissions declined, overdose deaths increased in recent years. Acceptance and proliferation of - mainly local/community-based - health measures (e.g., needle exchange, crack paraphernalia or naloxone distribution) aiming at high-risk drug users has evolved, though reach and access limitations have persisted; Vancouver's 'supervised injection site' has attracted continued attention yet remains un-replicated elsewhere in Canada. While opioid maintenance treatment utilization increased, access to treatment for key (e.g., infectious disease, psychiatric) co-morbidities among drug users remained limited. Law enforcement continued to principally focus on cannabis and specifically cannabis users. 'Drug treatment courts' were introduced but have shown limited effectiveness; several attempts cannabis control law reform have failed, except for the recent establishment of 'medical cannabis' access provisions.

CONCLUSIONS

While recent federal governments introduced several law and policy measures reinforcing a repression approach to illicit drug use, lower-level jurisdictions (e.g., provincial/municipal levels) and non-governmental organizations increasingly promoted social- and health-oriented intervention frameworks and interventions, therefore creating an increasingly bifurcated - and inherently contradictory - drug policy landscape and reality in Canada.

Methamphetamine injecting is associated with phylogenetic clustering of hepatitis C virus infection among street-involved youth in Vancouver, Canada

BACKGROUND

Among prospective cohorts of people who inject drugs (PWID), phylogenetic clustering of HCV infection has been observed. However, the majority of studies have included older PWID, representing distant transmission events. The aim of this study was to investigate phylogenetic clustering of HCV infection among a cohort of street-involved youth.

METHODS

Data were derived from a prospective cohort of street-involved youth aged 14-26 recruited between 2005 and 2012 in Vancouver, Canada (At Risk Youth Study, ARYS). HCV RNA testing and sequencing (Core-E2) were performed on HCV positive participants. Phylogenetic trees were inferred using maximum likelihood methods and clusters were identified using ClusterPicker (Core-E2 without HVR1, 90% bootstrap threshold, 0.05 genetic distance threshold).

RESULTS

Among 945 individuals enrolled in ARYS, 16% (n=149, 100% recent injectors) were HCV antibody positive at baseline interview (n=86) or seroconverted during follow-up (n=63). Among HCV antibody positive participants with available samples (n=131), 75% (n=98) had detectable HCV RNA and 66% (n=65, mean age 23, 58% with recent methamphetamine injection, 31% female, 3% HIV+) had available Core-E2 sequences. Of those with Core-E2 sequence, 14% (n=9) were in a cluster (one cluster of three) or pair (two pairs), with all reporting recent methamphetamine injection. Recent methamphetamine injection was associated with membership in a cluster or pair (P=0.009).

CONCLUSION

In this study of street-involved youth with HCV infection and recent injecting, 14% demonstrated phylogenetic clustering. Phylogenetic clustering was associated with recent methamphetamine injection, suggesting that methamphetamine drug injection may play an important role in networks of HCV transmission.

Factors associated with initiating someone into illicit drug injection

AIMS

Most people who inject drugs (PWID) were first initiated into injection by a current PWID. Few studies have examined PWID who assist others into drug injection. Our goal is to describe the prevalence of and risk factors for initiating someone into injection in the last 12 months.

METHODS

We recruited a cross-sectional sample of PWID (N=605) in California from 2011 to 2013. We examined bivariate and multivariate risk factors for initiating someone into injection with a focus on behaviors that might encourage injection initiation such as injecting in front of non-PWID, describing how to inject to non-PWID, and willingness to initiate someone into drug injection.

RESULTS

Having initiated someone into injection was reported by 34% of PWID overall and 7% in the last 12 months. Forty-four PWID had assisted 431 people into injection in the past year. Factors independently associated with initiating someone into injection in the last 12 months were self-reported likelihood of initiating someone in the future (Adjusted Odds Ratio [AOR]=7.09; 95% Confidence Interval [CI]=3.40, 14.79), having injected another PWID in past month (AOR=4.05; 95% confidence interval [CI]=1.94, 8.47), having described how to inject to non-injectors (2.61; 95% CI=1.19, 5.71), and non-injection powder cocaine use in past month (AOR=4.97; 95% CI=2.08, 11.84) while controlling for study site.

CONCLUSION

Active PWID are important in facilitating the process of drug injection uptake. Interventions to reduce initiation should include efforts to change behaviors and intentions among PWID that are associated with injection uptake among others.

Health and social harms associated with crystal methamphetamine use among street-involved youth in a Canadian setting

BACKGROUND AND OBJECTIVES

Despite recent increases in crystal methamphetamine use among high-risk populations such as street-involved youth, few prospective studies have examined the health and social outcomes associated with active crystal methamphetamine use.

METHODS

We enrolled 1,019 street-involved youth in Vancouver, Canada, in a prospective cohort known as the at-risk youth study (ARYS). Participants were assessed semi-annually and a generalized estimating equation (GEE) logistic regression was used to identify factors independently associated with active crystal methamphetamine use.

RESULTS

Among 1,019 participants recruited into ARYS between 2005 and 2012 the median follow up duration was 17 months, 320 (31.4%) participants were female and 454 (44.6%) had previously used crystal methamphetamine at baseline. In adjusted GEE analyses, active crystal methamphetamine use was independently associated with Caucasian ethnicity (adjusted odds ratio [AOR] = 1.37; 95% confidence interval [CI]: 1.04-1.81), homelessness (AOR = 1.34; 95% CI: 1.15-1.56), injection drug use (AOR = 3.40; 95% CI: 2.76-4.19), non-fatal overdose (AOR = 1.46; 95%CI: 1.07-2.00), being a victim of violence (AOR = 1.19; 95% CI: 1.02-1.38), involvement in sex work (AOR = 1.39; 95% CI: 1.03-1.86), and drug dealing (AOR = 1.60; 95% CI: 1.35-1.90).

DISCUSSION AND CONCLUSIONS

Prevalence of crystal methamphetamine use was high in this setting and active use was independently associated with a range of serious health and social harms.

SCIENTIFIC SIGNIFICANCE

Evidence-based strategies to prevent and treat crystal methamphetamine use are urgently needed.

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.

Stress modulates illness-course of substance use disorders: a translational review

Childhood trauma and post-childhood chronic/repeated stress could increase the risk of a substance use disorder by affecting five stages of addiction illness-course: (a) initial experimentation with substances; (b) shifting from experimental to regular use; (c) escalation from regular use to abuse or dependence; (d) motivation to quit; and (e) risk of (re-)lapse. We reviewed the human literature on relationships between stress and addiction illness-course. We explored per illness-course stage: (i) whether childhood trauma and post-childhood chronic/repeated stress have comparable effects and (ii) whether effects cut across classes of substances of abuse. We further discuss potential underlying mechanisms by which stressors may affect illness-course stages for which we relied on evidence from studies in animals and humans. Stress and substances of abuse both activate stress and dopaminergic motivation systems, and childhood trauma and post-childhood stressful events are more chronic and occur more frequently in people who use substances. Stressors increase risk to initiate early use potentially by affecting trait-like factors of risk-taking, decision making, and behavioral control. Stressors also accelerate transition to regular use potentially due to prior effects of stress on sensitization of dopaminergic motivation systems, cross-sensitizing with substances of abuse, especially in people with high trait impulsivity who are more prone to sensitization. Finally, stressors increase risk for abuse and dependence, attenuate motivation to quit, and increase relapse risk potentially by intensified sensitization of motivational systems, by a shift from positive to negative reinforcement due to sensitization of the amygdala by corticotropin releasing factor, and by increased sensitization of noradrenergic systems. Stress generally affects addiction illness-course across stressor types and across classes of substances of abuse.

Crystal methamphetamine initiation among street-involved youth

BACKGROUND

Although many settings have recently documented a substantial increase in the use of methamphetamine-type stimulants, recent reviews have underscored the dearth of prospective studies that have examined risk factors associated with the initiation of crystal methamphetamine use.

OBJECTIVES

Our objectives were to examine rates and risk factors for the initiation of crystal methamphetamine use in a cohort of street-involved youth.

METHODS

Street-involved youth in Vancouver, Canada, were enrolled in a prospective cohort known as the At-Risk Youth Study (ARYS). A total of 205 crystal methamphetamine-naïve participants were assessed semi-annually and Cox regression analyses were used to identify factors independently associated with the initiation of crystal methamphetamine use.

RESULTS

Among 205 youth prospectively followed from 2005 to 2012, the incidence density of crystal methamphetamine initiation was 12.2 per 100 person years. In Cox regression analyses, initiation of crystal methamphetamine use was independently associated with previous crack cocaine use (adjusted relative hazard [ARH] = 2.24 [95% CI: 1.20-4.20]) and recent drug dealing (ARH = 1.98 [95% CI: 1.05-3.71]). Those initiating methamphetamine were also more likely to report a recent nonfatal overdose (ARH = 3.63 [95% CI: 1.65-7.98]) and to be male (ARH = 2.12 [95% CI: 1.06-4.25]).

CONCLUSIONS

We identified high rates of crystal methamphetamine initiation among this population. Males those involved in the drug trade, and those who used crack cocaine were more likely to initiate crystal methamphetamine use. Evidence-based strategies to prevent and treat crystal methamphetamine use are urgently needed.

Gender difference in the characteristics of and high-risk behaviours among non-injecting heterosexual methamphetamine users in Qingdao, Shandong Province, China

Background

Despite the increasing risk of HIV infections, few studies concerning the characteristics of non-injecting heterosexual methamphetamine (MA) users and related risk behaviours have been conducted in China.

Methods

Gender differences in socio-demographic characteristics, perception of MA and STD/HIV, MA use practices, and sexual behaviours related to MA use were examined among 398 non-injecting heterosexual MA users (288 males, 110 females).

Results

Male MA users were more likely to be married, local, and self-employed; female MA users were more likely to be young, single, engaged in commercial service or unemployed. Female MA users usually start MA use at an earlier age than males (24.3 vs. 31.3 years old), with shorter abuse durations (2.6 vs. 2.9 years), higher frequency of MA use (3.6 vs. 2.4 times per week), and higher likelihood of using MA with heterosexual partners (100% vs. 78.1%). More male MA users have had multiple sex partners (96.9% vs. 77.3%) and sex exchanges (72.9% vs. 46.4%). Among 277 males who had had sex with commercial sex workers (CSW), 69.4% never used condoms, and among 77 males who had had sex with multiple partners who are commercial sex workers and always or usually used condoms, 87.0% never changed condoms when changing partners.

Conclusion

There may be gender difference in the characteristics of high-risk behaviours among non-injecting heterosexual MA users. The findings suggest the integration of specific risk reduction strategies into intervention programs for non-injecting heterosexual MA user populations may significantly improve program goals.

Social, structural and behavioral determinants of overall health status in a cohort of homeless and unstably housed HIV-infected men

BACKGROUND

Previous studies indicate multiple influences on the overall health of HIV-infected persons; however, few assess and rank longitudinal changes in social and structural barriers that are disproportionately found in impoverished populations. We empirically ranked factors that longitudinally impact the overall health status of HIV-infected homeless and unstably housed men.

METHODS AND FINDINGS

Between 2002 and 2008, a cohort of 288 HIV+ homeless and unstably housed men was recruited and followed over time. The population was 60% non-Caucasian and the median age was 41 years; 67% of study participants reported recent drug use and 20% reported recent homelessness. At baseline, the median CD4 cell count was 349 cells/µl and 18% of eligible persons (CD4<350) took antiretroviral therapy (ART). Marginal structural models were used to estimate the population-level effects of behavioral, social, and structural factors on overall physical and mental health status (measured by the SF-36), and targeted variable importance (tVIM) was used to empirically rank factors by their influence. After adjusting for confounding, and in order of their influence, the three factors with the strongest negative effects on physical health were unmet subsistence needs, Caucasian race, and no reported source of instrumental support. The three factors with the strongest negative effects on mental health were unmet subsistence needs, not having a close friend/confidant, and drug use. ART adherence >90% ranked 5th for its positive influence on mental health, and viral load ranked 4th for its negative influence on physical health.

CONCLUSIONS

The inability to meet food, hygiene, and housing needs was the most powerful predictor of poor physical and mental health among homeless and unstably housed HIV-infected men in an urban setting. Impoverished persons will not fully benefit from progress in HIV medicine until these barriers are overcome, a situation that is likely to continue fueling the US HIV epidemic.