Polydrug Use and Heterogeneity in HIV Risk Among People Who Inject Drugs in Estonia and Russia: A Latent Class Analysis

Dual HIV risk and vulnerabilities among people who inject drugs in Iran: Findings from a nationwide study in 2020

INTRODUCTION

People who inject drugs (PWID) are a key population at risk of HIV in Iran. We measured the prevalence and covariates of HIV-related risk behaviours among PWID in Iran.

METHODS

We conducted a respondent-driven bio-behavioural surveillance survey among PWID from July 2019 to March 2020 in 11 major cities. We assessed PWID's recent (i.e., last three months) HIV-related risk behaviours using a four-level categorical variable: Only unsafe injection (i.e., sharing needles/syringes or injecting equipment), only unsafe sex (i.e., unprotected sex), dual HIV risk (i.e., both unsafe injection and unprotected sex), and safe injection and sex. Data were summarized using RDS-weighted analysis. Multinomial logistic regression models were built to characterize HIV-related risk behaviours and relative risk ratio (RRR) with 95% confidence interval (CI) were reported.

RESULTS

Overall, 2562 men who inject drugs (MWID) were included in the regression analysis. The RDS-weighted prevalence of dual HIV risk was 1.3% (95% CI: 0.8, 1.9), only unsafe injection was 4.5%, and only unsafe sex was 11.8%. Compared to the safe injection and sex group, dual HIV risk was significantly and positively associated with multiple partnership (RRR = 15.06; 3.30, 68.73). Only unsafe injection was significantly associated with homelessness in the last 12 months (RRR: 3.02; 95% CI: 1.34, 6.80). Only unsafe sex was significantly associated with multiple partnership (RRR = 6.66; 4.27, 10.38), receiving free condoms (RRR = 1.71; 1.01, 2.89), receiving free needles (RRR = 2.18; 1.22, 3.90), and self-received risk for HIV (RRR = 2.51; 1.36, 4.66). Moreover, history of HIV-testing in the last three months was significantly associated with only unsafe injection (RRR = 2.71; 1.84, 3.80). Among the 90 women who injected drugs, none reported dual HIV risk behaviours.

DISCUSSION AND CONCLUSIONS

While the low prevalence of dual HIV risk among PWID is encouraging, unprotected sexual practices among PWID is concerning. Expanding sexual health education and care services as well as tailored interventions aimed at reducing high-risk sexual activities among PWID are warranted. Additionally, tackling potential misperceptions about risk of HIV transmission among PWID in Iran is warranted.

Can platform use patterns be an indicator of HIV-related risk and sub-group heterogeneity among men who have sex with men in Singapore: a latent class analysis

Introduction

Low-level HIV epidemic settings like Singapore face the challenge of reaching men at-risk who have less contact with programmes. We investigated patterns of meeting platform use by men seeking male sexual partners (MSM) as potential marker of risk to differentiate sub-groups for interventions.

Methods

Latent Class Analysis (LCA) was applied to a survey sample of MSM recruited from bars/clubs, saunas and a smartphone application, using purposive sampling. The best-fit LCA model which identified homogeneous sub-groups with similar patterns of meeting platform was factored in multivariable regression to identify associations with risk behaviors on the pathway to HIV infection.

Results

Overall 1,141 MSM were recruited from bars/clubs (n = 426), saunas (n = 531), and online (n = 184). Five patterns emerged, reflecting salient platform use characteristics: Sauna-centric (SC; n = 413), App-centric (AC; n = 276), Multiple-platforms (MP; n = 123), Platform-inactive (PI; n = 257), and "Do not hook up" (DNH; n = 72) classes. Men in the SC and MP classes had high probabilities of using saunas to meet partners; SC were older and less likely to have disclosed their sexual orientation. The MP class had high probabilities of connecting across all platforms in addition to saunas and more likely to have disclosed their sexual orientation, than the PI class. Men in the SC and MP classes had twice the odds of reporting multiple sex partners (aORSC = 2.1; 95%CI: 1.33.2; aORMP = 2.2; 95%CI: 1.14.6). Single/non-partnered MSM and those using alcohol/drugs during sex had 1.7 (95%CI: 1.22.5) and 3.2 (95%CI: 2.05.1) the odds respectively, of reporting multiple sex partners. The SC and MP classes had higher odds of engaging in group sex while MSM using alcohol/drugs during sex had twice the odds of reporting group sex. Alcohol/drugs and group sex were independently associated with condomless sex (as was lower education). Group sex, alcohol/drugs during sex, disclosure of sexual orientation or being Singaporean/permanent resident were associated with recent testing for HIV.

Discussion

The five distinct risk profiles identified can help tailor differentiated HIV interventions-combined with field knowledge and other prevention-to expand HIV self-testing, Pre-Exposure Prophylaxis and other services (e.g., Mpox vaccination) to sub-groups at risk.

Polysubstance Use Profiles and HIV Viremia in a South African Cohort of Female Sex Workers: A Latent Class Analysis

BACKGROUND

Given intersecting social and structural factors, female sex workers (FSW) exhibit elevated risk of HIV and substance use. However, there is limited study of how distinct substance use typologies influence HIV treatment outcomes among FSW.

SETTING

A cross-sectional survey with objective viral load assessments of 1391 FSW enrolled into a treatment optimization-focused trial in Durban, South Africa (2018-2020).

METHODS

We used latent class analysis to uncover discrete patterns in past-month self-reported use of the following substances: heavy alcohol use, cannabis, cocaine, crack, ecstasy, methamphetamine, heroin, and Whoonga . We used Wald tests to identify multilevel predictors of latent class membership and multivariable mixture modeling to quantify associations of substance use classes with HIV viremia (≥50 RNA copies/mL).

RESULTS

Substance use (87%) and HIV viremia (62%) were highly prevalent. Latent class analysis uncovered 3 polysubstance use profiles: Heavy Alcohol Use Only (∼54%); Cannabis, Heavy Alcohol, & Crack Use (∼28%); and Whoonga & Crack Use (∼18%). Whoonga & Crack Use was associated with social and structural adversities, including homelessness, outdoor/public sex work, HIV stigma, and violence. Relative to Heavy Alcohol Use Only , HIV viremia was significantly higher in the Whoonga & Crack Use class (adjusted odds ratio 1.97, 95% confidence interval: 1.13 to 3.43), but not in the Cannabis, Heavy Alcohol, & Crack Use class (adjusted odds ratio 1.17, 95% confidence interval: 0.74 to 1.86).

CONCLUSION

HIV viremia differed significantly across identified polysubstance use profiles among South African FSW. Integrating drug treatment and harm reduction services into HIV treatment programs is key to improving virologic outcomes in marginalized communities.

Stigma and other correlates of sharing injection equipment among people with HIV in St. Petersburg, Russia

Stigma that people with HIV who inject drugs experience negatively impacts HIV and substance use care, but stigma's association with sharing injection equipment is not known. This is a cross-sectional analysis of data from two studies of people with HIV reporting drug injection (N = 319) in St. Petersburg, Russia (September 2018-December 2020). We used logistic regression to examine associations between HIV stigma and substance use stigma scores (categorised into quartiles) and past 30-day equipment sharing, adjusting for demographic and clinical characteristics. Secondary analyses examined associations of arrest history and social support with sharing equipment. Almost half (48.6%) of participants reported sharing injection equipment. Among groups who did and did not share, mean HIV stigma (2.3 vs 2.2) and substance use stigma (32 vs 31) scores were similar. Adjusted analyses detected no significant associations between HIV stigma quartiles (global p-value = 0.85) or substance use stigma quartiles (global p-value = 0.51) and sharing equipment. Neither arrest history nor social support were significantly associated with sharing equipment. In this cohort, sharing injection equipment was common and did not vary based on stigma, arrest history, or social support. To reduce equipment sharing, investments in sterile injection equipment access in Russia should be prioritised over interventions to address stigma.

Associations of hepatitis C virus (HCV) antibody positivity with opioid, stimulant, and polysubstance injection among people who inject drugs (PWID) in rural U.S. communities

BACKGROUND

People who inject drugs (PWID) in the rural U.S. often inject stimulants, alone or with opioids. The impact of these substance use patterns may influence HCV risk behaviors. This analysis examines the associations of HCV antibody positivity with injecting only opioids, only stimulants (methamphetamine/cocaine), and opioids and stimulants together among rural PWID.

METHODS

The Rural Opioid Initiative (ROI) consists of eight research sites that enrolled people who use drugs in rural communities in ten U.S. states from 2018 to 2020. This cross-sectional analysis included adult participants who resided in a study area and injected any drug in the past 30 days. The primary outcome was HCV antibody positivity. The exposure of interest was injection drug use classified as only opioids, only stimulants, separate injections of opioids and stimulants, and same-syringe injection of both in the past 30 days. We used multivariable log-binomial regression with generalized linear mixed models to generate prevalence ratios (P.R.) adjusted for demographics, injection history, health insurance, and substance use treatment.

RESULTS

Among 3,084 participants enrolled in the ROI, 1,982 met inclusion criteria. Most participants injected opioids and stimulants in the same syringe (34%) or separately (21%), followed by injecting only stimulants (26%), and injecting only opioids (19%). Half (51%) were HCV antibody positive. Compared to people who injected only stimulants, HCV antibody positivity was more prevalent among people who injected opioids alone (aPR=1.62, 95% CI:(1.29-2.03)), injected both opioids and stimulants separately (aPR=1.61, 95% CI:(1.32-1.95)), and in the same syringe (aPR=1.54, 95% CI:(1.28-1.85)).

CONCLUSION

HCV antibody positivity, indicating prior exposure, was highest among those who had recently injected opioids, alone or with stimulants. Additional nucleic acid testing is necessary to confirm active infection. More research is needed to determine the underlying causes of HCV antibody positivity by injection use.

Trends and associated factors of HIV, HCV and syphilis infection among different drug users in the China-Vietnam border area: an 11-year cross-sectional study (2010-2020)

BACKGROUND

Data on recent human immunodeficiency virus (HIV), hepatitis C virus (HCV) and syphilis prevalence among drug users in the Southwest China are sparse despite the high burden of drug use. This study aims at assessing the prevalence trends and related factors of HIV, HCV and syphilis infection among different drug users in the China-Vietnam border area.

METHODS

A continuous cross-sectional survey was conducted among drug users from 2010 to 2020 in the China-Vietnam border area. Chi-square trend tests were used to assess the trend of HIV, HCV and syphilis prevalence and the proportion for drug type used by drug users. Multivariate logistic regression was used to identify associated factors of HIV, HCV and syphilis infection in different drug users.

RESULTS

In this study, a total of 28,951 drug users were included, of which 27,893 (96.45%) male, 15,660 (54.09%) aged 13-34 years, 24,543 (84.77%) heroin-only users, 2062 (7.12%) synthetic drug-only (SD-only) users and 2346 (8.10%) poly-drug users. From 2010 to 2020, the proportion of heroin-only users decreased from 87.79% to 75.46%, whereas SD-only users and poly-drug users increased from 5.16% to 16.03%, and from 7.05% to 8.52%, respectively. The prevalence of HIV, HCV, and syphilis during the study period declined from 12.76%, 60.37% and 5.72% to 4.35%, 53.29% and 4.53%, respectively, among heroin-only users and declined from 18.30%, 66.67% and 15.69% to 6.95%, 27.81% and 5.35%, respectively, among poly-drug users; however, the prevalence of HIV and HCV among SD-only users increased from 0.89% and 8.93% to 2.84% and 18.75%, respectively. Having ever injected drugs and needle sharing were common associated factors for both HIV and HCV infection among poly-drug users and heroin-only users. Aged ≥ 35 years old was an associated factor for HIV, HCV and syphilis infection among the SD-only users. Female drug users were at high risk of contracting syphilis among three different drug users.

CONCLUSIONS

The prevalence of HIV, HCV and syphilis among heroin-only users and poly-drug users decreased during the study period. However, the prevalence of HIV and HCV among SD-only users increased. Comprehensive intervention strategies, particularly focusing on the SD-only users are needed in order to bring down the disease burden in this population in the China-Vietnam border areas.

Behavioral Risk Factors for HIV Infection in Hospitalized Persons Who Co-use Stimulants and Opioids

We investigated the association of 90-day opioid and stimulant co-use and HIV risk behaviors in a cross-sectional analysis of hospitalized HIV-negative people who inject drugs (PWID). We compared those injecting opioids alone to two sub-groups who co-used opioids with (1) cocaine, (2) amphetamine-type stimulants (ATS), on sex and injection drug risk behaviors assessed via the Risk Assessment Battery (RAB), where a higher score indicates a higher risk. Of 197 participants who injected opioids, 53% co-used cocaine only, 5% co-used ATS only, 18% co-used both cocaine and ATS, 24% co-used neither stimulant. PWID who injected opioids alone had a mean RAB drug risk score of 5.98 points and sex risk score of 2.16 points. Compared to PWID who injected opioids alone, PWID who co-used stimulants had higher mean drug risk RAB scores: cocaine, b = 2.84 points [95% confidence interval (CI) 1.01; 4.67]; ATS, b = 3.43 points (95% CI 1.29; 5.57). Compared to PWID who injected opioids alone, cocaine co-use was associated with higher sex RAB scores b = 1.06 points (95% CI 0.32; 1.79). Overall, we found a significant association between stimulant co-use and higher HIV sex and drug risk scores.

Challenges of sexually transmitted infections and sexual health among people who inject drugs

PURPOSE OF REVIEW

This review provides a summary of recently published research on sexually transmitted infections (STI) and related behaviors among people who inject drugs (PWID), covering three major areas: sexual behavior and its role in STI transmission among PWID, multilevel factors associated with STI risk, and strategies addressing sexual health of PWID. This review is timely given the growing priority of combination prevention approaches and integrated care for PWID.

RECENT FINDINGS

Modern research improves the understanding that PWID have an increased risk of STI, which varies by gender, setting, type of substance used, and presence of mental disorders. Major socioeconomic and structural factors, specific and nonspecific to PWID, facilitate inequality and sexual risk behavior. Sexual transmission continues to contribute substantially to the spread of bloodborne infections among PWID, accounting for at least 10% of new HIV cases according to epidemiological modeling. Despite the substantial evidence that behavioral interventions can improve sexual health and reduce sex-related risks among PWID, there is a research-practice gap, reflected in the scarcity of implementation studies published recently.

SUMMARY

Integration of sexual health into prevention programs for PWID is essential to curb transmission of STI, including HIV, among PWID and their sexual partners.

Violence, HIV Risks, and Polysubstance Use Among HIV-Positive People Who Inject Drugs in Ukraine

Violence experience has been consistently associated with HIV risks and substance use behaviors. Although many studies have focused on intimate partner violence (IPV), the role of violence at a structural level (i.e., police abuse) remains relevant for people who inject drugs. This study evaluated the association of IPV and police-perpetrated violence experiences with HIV risk behaviors and substance use in a cohort of HIV-positive people who inject drugs in Ukraine. We also evaluated possible moderation effects of gender and socioeconomic status in the links between violence exposure and HIV risk and polysubstance use behaviors. Data came from the Providence/Boston-CFAR-Ukraine Study involving 191 HIV-positive people who inject drugs conducted at seven addiction treatment facilities in Ukraine. Results from logistic regressions suggest that people who inject drugs and experienced IPV had higher odds of polysubstance use than those who did not experience IPV. Verbal violence and sexual violence perpetrated by police were associated with increased odds of inconsistent condom use. The odds of engaging in polysubstance use were lower for women in relation to police physical abuse. We found no evidence supporting socioeconomic status moderations. Violence experiences were associated with substance use and sexual HIV risk behaviors in this cohort of HIV-positive people who inject drugs in Ukraine. Trauma-informed prevention approaches that consider both individual and structural violence could improve this population's HIV risks.

Prevalence and correlates of simultaneous, multiple substance injection (co-injection) among people who inject drugs in Melbourne, Australia

AIMS

To estimate the prevalence of and risk factors associated with concurrent injection of multiple substances (co-injection) among a community-recruited cohort of people who inject drugs.

DESIGN

Cross-sectional study.

SETTING

Melbourne, Australia.

PARTICIPANTS

A sample of 720 actively injecting participants from the Melbourne Injecting Drug User Cohort Study (33% female) was extracted.

MEASUREMENTS

We constructed two statistical models: a logistic regression model analysing correlates of co-injection of any substance combination in the past month and a multinomial logistic regression model analysing correlates of three mutually exclusive groups: heroin-diphenhydramine co-injection only, co-injection of other substances and no co-injection. Risk factors examined included drug use characteristics, demographic characteristics, health service use, hepatitis C status, injection risk behaviours and previous experience of non-fatal overdose.

FINDINGS

One-third [n = 226, 31%; 95% confidence interval (CI): 28-34%] of participants reported co-injecting substances within the past month, with equal numbers of participants reporting injecting combinations of heroin-diphenhydramine (n = 121, 54%; 95% CI = 48-60%) and heroin-methamphetamine (n = 121, 54%; 95% CI = 48-60%). In logistic regression analyses, reporting co-injection of any substance combination was associated with male sex [adjusted odds ratio (aOR) = 1.80, 95% CI = 1.18-2.74, P = 0.006] and injecting daily or more frequently (aOR = 2.04, 95% CI = 1.31-3.18, P = 0.002). In multinomial logistic regression analyses, participants reporting heroin-diphenhydramine co-injection only were significantly more likely to report groin injecting [adjusted relative risk ratio (aRRR) = 6.16, 95% CI = 2.80-13.56, P < 0.001] and overdose (requiring an ambulance) in the past 12 months (aRRR = 2.81, 95% CI = 1.17-6.72, P = 0.021) compared with participants reporting no co-injection or co-injection of other substances.

CONCLUSIONS

A substantial proportion of people who inject drugs report co-injection of multiple substances, which is associated with a range of socio-demographic, drug use and health service use risk factors.

Injection drug use, depression, and HIV screening in rural primary care settings: A retrospective cross-sectional study

Introduction

Antiretroviral therapy (ART) has reduced HIV viral replication and transmission of disease. However, continuing incidence of new HIV infections has been attributed to undiagnosed HIV infections among injection drug users. This purpose of this retrospective cross-sectional study was to determine whether depression moderates the relationship between injection drug use and HIV screening among people with substance use in the screening, brief intervention, and referral to treatment in Alabama (AL-SBIRT) program.

Methods

Electronic health record data were obtained from three consenting medical facilities (n = 103). Multivariable logistic regression analysis was conducted to determine the moderating effect of depression on the relationship between injection drug use and HIV screening.

Results

Bivariate analyses revealed that HIV screening was more common among individuals not engaged in injection drug use, 75% and 57% respectively. Participants who had never been screened had worse depressive symptoms on the PHQ-2 (M = 3.00, SE = 0.42) than individuals who had been screened for HIV (M = 1.45, SE = 0.17). After controlling for demographic variables, tobacco use, alcohol consumption, and drug abuse, results indicated a moderating effect of depression on the relationship between injection drug use and receipt of HIV screening (aOR = 0.85 [95% CI = 0.84, 0.86).

Discussion

Findings suggest that high risk subgroups such as injection drug users with severe depression may not be using HIV prevention services, leading to possible delays in HIV diagnosis. Integration of behavioral interventions and HIV prevention services may reduce risk factors among depressed injection drug users. Such interventions may improve retention for injection drug users who experience worse depressive symptoms post HIV diagnosis.

Combination HIV Prevention Strategies Among Montreal Gay, Bisexual, and Other Men Who Have Sex with Men in the PrEP Era: A Latent Class Analysis

Pre-exposure prophylaxis (PrEP) became publicly available in Quebec for gay, bisexual and other men who have sex with men (GBM) in 2013. We used baseline data from Engage, a cohort of GBM recruited by respondent-driven sampling, to examine patterns of combination HIV prevention use among Montreal GBM since PrEP became available. Latent class analysis, stratified by HIV status, was used to categorize GBM by self-reported use of biomedical and behavioural prevention strategies. Correlates of resulting classes were identified using multinomial logistic regression. Among HIV-negative/unknown GBM (n = 968), we identified four classes: low use of prevention (32%), condoms (40%), seroadaptive behaviour (21%), and biomedical (including PrEP; 7%). Those using prevention (condoms, seroadaptive behaviour, and biomedical) had a higher number of anal sex partners and were more likely to report a recent sexually transmitted infection diagnosis. GBM using biomedical prevention also had a higher level of formal education. Among GBM living with HIV (n = 200), we identified three classes: mainly antiretroviral treatment (ART) with viral suppression (53%), ART with viral suppression and condoms (19%), and ART with viral suppression and seroadaptive behaviour (18%). Again, the number of anal sex partners was higher among those using condoms and seroadaptive behaviours. Our findings show antiretroviral-based prevention, either alone or in combination with other strategies, is clearly a component of the HIV prevention landscape for GBM in Montreal. Nevertheless, PrEP uptake remains low, and there is a need to promote its availability more widely.

Sex differences in the multilevel determinants of injection risk behaviours among people who inject drugs in Tijuana, Mexico

INTRODUCTION AND AIMS

HIV and hepatitis C virus transmission among people who inject drugs (PWID) is fuelled by personal and environmental factors that vary by sex. We studied PWID in Mexico to identify sex differences in multilevel determinants of injection risk.

DESIGN AND METHODS

From 2011 to 2013, 734 PWID (female: 277, male: 457) were enrolled into an observational cohort study in Tijuana. Participants completed interviews on injection and sexual risks. Utilising baseline data, we conducted multiple generalised linear models stratified by sex to identify factors associated with injection risk scores (e.g. frequency of injection risk behaviours).

RESULTS

For both sexes, difficult access to sterile syringes was associated with elevated injection risk (b = 1.24, 95% confidence interval [CI] 1.16-1.33), using syringes from a safe source (e.g. needle exchange programs) was associated with lower injection risk (b = 0.87, 95% CI 0.82-0.94), and for every one-unit increase in safe injection self-efficacy we observed a 20% decrease in injection risk (b = 0.80, 95% CI 0.76-0.84). Females had a higher safe injection self-efficacy score compared to males (median 2.83, interquartile range 2.2-3 vs. median 2.83, interquartile range 2-3; P = 0.01). Among females, incarceration (b = 1.22, 95% CI 1.09-1.36) and police confiscation of syringes in the past 6 months (b = 1.16, 95% CI 1.01-1.33) were associated with elevated injection risk. Among males, sex work (b = 1.16, 95% CI 1.04-1.30) and polysubstance use in the past 6 months (b = 1.22, 95% CI 1.13-1.31) were associated with elevated injection risk.

DISCUSSION AND CONCLUSIONS

Interventions to reduce HIV and hepatitis C virus transmission among PWID in Tijuana should be sex-specific and consider multilevel determinants of injection risk to create safer drug use environments.

Estimating the contribution of stimulant injection to HIV and HCV epidemics among people who inject drugs and implications for harm reduction: A modeling analysis

BACKGROUND

Stimulants, such as amphetamines and cocaine, are widely injected among people who inject drugs (PWID). Systematic reviews indicate stimulant injection is associated with HIV and HCV among PWID. Using these associations, we estimated the contribution of stimulant injection to HIV and HCV transmission among PWID.

METHODS

We modeled HIV and HCV transmission among PWID, incorporating excess injecting and sexual risk among PWID who inject stimulants. We simulated three illustrative settings with different stimulants injected, prevalence of stimulant injecting, and HIV/HCV epidemiology. We estimated one-year population attributable fractions of stimulant injection on new HIV and HCV infections, and impact of scaling up needle-syringe programs (NSP).

RESULTS

In low prevalence settings of stimulant injection (St. Petersburg-like, where 13 % inject amphetamine), 9% (2.5-97.5 % interval [95 %I]: 6-15 %) and 7% (95 %I 4-11 %) of incident HIV and HCV cases, respectively, could be associated with stimulant injection in the next year. With moderate stimulant injection (Montreal-like, where 34 % inject cocaine), 29 % (95 %I: 19-37 %) and 19 % (95 %I: 16-21 %) of incident HIV and HCV cases, respectively, could be associated with stimulant injection. In high-burden settings like Bangkok where 65 % inject methamphetamine, 23 % (95%I:10-34%) and 20 % (95%I: 9-27%) of incident HIV and HCV cases could be due to stimulant injection. High-coverage NSP (60 %) among PWID who inject stimulants could reduce HIV (by 22-65 %) and HCV incidence (by 7-11 %) in a decade.

DISCUSSION

Stimulant injection contributes substantially to HIV and HCV among PWID. NSP scale-up and development of novel interventions among PWID who inject stimulants are warranted.

Changes in substance use in relation to opioid agonist therapy among people who use drugs in a Canadian setting

BACKGROUND

Although previous studies have shown that opioid agonist therapy (OAT) is linked to reductions in illicit opioid use, less is known about how OAT impacts the use of other psychoactive substances. We aimed to examine the changes in use of different substances by comparing patterns before and after initiating OAT.

METHODS

Data for this study was derived from three ongoing prospective cohorts involving people who use drugs in Vancouver, Canada from 1996 to 2018. We assessed use patterns for heroin, illicit prescription opioid, cocaine, crack cocaine, crystal methamphetamine, cannabis, daily alcohol use, and benzodiazepines. Segmented regression was conducted to compare the trends of substance use between pre-treatment and post-treatment periods.

RESULTS

The study included 1107 participants. After OAT engagement, we observed an immediate decline in the proportion as well as a decreasing trend for heroin (Adjusted Odds Ratio (AOR): 0.80, 95% confidence interval (CI): 0.77, 0.83), illicit prescription opioid (AOR: 0.87, 95% CI: 0.83, 0.90), and benzodiazepines (AOR: 0.73, 95 % CI: 0.67, 0.80). There was no significant difference comparing the pre-treatment and post-treatment trends for cocaine, crack cocaine, crystal methamphetamine, and cannabis. However, higher growth slope was noted during the post-treatment period for daily alcohol use (P = 0.016).

CONCLUSIONS

We observed significant reduction in illicit opioids use following OAT initiation, but not for stimulant and cannabis. The increasing problematic use of alcohol may pose challenges to the safety and effectiveness of OAT. Development of comprehensive and tailored treatment strategies is needed for poly-substance users accessing OAT.

Estimation of the impact of changing drug-use trend on HIV, hepatitis C and syphilis epidemics among people who use synthetic drug-only, polydrug and heroin-only during 2005-2035 in China: modelling study

OBJECTIVE

The rapid expansion of the recreational drug market becomes a global health concern. It is worrying that the bacterial and viral infection epidemics linking to drug use may worsen accordingly. This study aimed to estimate the impacts of changing trend and behaviours of using heroin only, synthetic drug (SD) only and polydrug (using SD and heroin concurrently) on HIV, hepatitis C virus (HCV) and syphilis epidemics among people who use drugs in China by 2035.

METHODS

We constructed a compartmental model to estimate HIV, HCV and syphilis epidemics in the dynamic drug-use trend by three scenarios: SD-only use, heroin-only use and polydrug use based on Monte Carlo simulations. The parameters for the model were collected from a comprehensive literature search.

RESULTS

Our model estimated that polydrug use led to the highest HIV and HCV prevalence among three drug-use patterns. The prevalences were projected to increase from 10.9% (95% CI 10.2% to 11.5%) and 61.7% (95% CI 59.4% to 62.5%) in 2005 to 19.0% (95% CI 17.3% to 20.7%) and 69.1% (95% CI 67.3% to 69.5%), respectively, in 2035 among people using polydrug. Similarly, HIV and HCV prevalence in the SD-only group were projected to increase from 0.4% (95% CI 0.3% to 0.4%) and 19.5% (95% CI 19.4% to 21.7%) to 1.8% (95% CI 1.4 to 2.1%) and 33.7% (95% CI 33.2% to 34.9%) in 2005-2035. Conversely, HIV prevalence in the heroin-only group was projected to decrease from 8.0% (95% CI 7.6% to 8.1%) to 2.2% (95% CI 2.0% to 2.3%) in 2005-2035. Syphilis prevalence was estimated to remain unchanged in all population groups within this time frame. It was projected that the proportion of HIV transmitted by sexual transmission will increase compared with unsafe injection transmission in all people who use drugs from 2005 to 2035.

CONCLUSION

Our modelling suggests that polydrug use is projected to lead to the highest HIV and HCV disease burden by 2035, and the proportion of HIV transmitted by sexual transmission will increase. Current HIV intervention among people using heroin seems effective according to our estimation.

Examining risk behavior and syringe coverage among people who inject drugs accessing a syringe services program: A latent class analysis

INTRODUCTION

Injection drug use (IDU) remains a significant public health problem. IDU has been associated closely with the opioid crisis; driving overdose, HIV, and Hepatitis C (HCV) infection nationwide. Syringe services programs (SSPs) remain pivotal evidence-based interventions to reduce harm and engage subgroups of people who inject drugs (PWID). This study aims to provide policy considerations from the IDEA SSP, the first legal SSP in the state of Florida.

METHODS

We performed a latent class analysis on patterns of substance use among participants (N = 982) newly enrolled in a syringe services program (SSP). Associations between classes of substance use and sociodemographic variables, risky injection and sex behaviors, HIV/HCV status and syringe coverage were analyzed using the R3STEP and BCH 3-step procedures in latent class regression.

RESULTS

We found a three-class solution: Heroin-Dominant class (73.9%), Methamphetamine-Dominant class (9.5%) and Heroin/Cocaine class (16.6%). Compared to Heroin-Dominant class, the Heroin/Cocaine class were more likely to report homelessness, sharing works, unprotected sex, public injection, and to be HCV positive. Compared to both Heroin-Dominant and Heroin/Cocaine classes, the Methamphetamine-Dominant class were more likely to be male, Hispanic, gay or bisexual orientation, HIV positive, to report unprotected sex and sex with PWID. In addition, the lowest and highest syringe coverage were among those in the Heroin/Cocaine and Methamphetamine-Dominant classes, respectively.

CONCLUSION

Existing interventions among this population to mitigate infectious disease risk, such as SSPs, can be a used to engage differing PWID populations. However, multi-component, targeted preventive interventions and need-based syringe distribution policies are required to further reduce HIV and HCV risk among various PWID populations.

Opioid Misuse Among HIV-Positive Adults in Medical Care: Results From the Medical Monitoring Project, 2009-2014

BACKGROUND

People living with HIV are prescribed opioids more often and at higher doses than people who do not have HIV, and disproportionately experience risk factors for substance use disorder, which suggests they could be at increased risk of the misuse of opioids. Researchers also suggest that opioid misuse negatively affects various HIV clinical outcomes, increasing the risk of transmission to partners with an HIV-negative status.

METHODS

We calculated weighted percentages and 95% confidence intervals to estimate substance use characteristics among a probability sample of 28,162 HIV-positive adults receiving medical care in the United States who misused opioids (n = 975). Then, we used Rao-Scott χ tests to assess bivariate associations between opioid misuse and selected characteristics.

RESULTS

In all, 3.3% misused opioids. Misuse was more common among young adults, males, and non-Hispanic whites. Persons who misused opioids were less likely to: have been prescribed antiretroviral therapy (ART) (88.7%), report being adherent to ART medications in the past 3 days (78.1%), and have durable viral suppression (54.3%) than persons who did not misuse opioids (92.5%, 87.7%, and 64.7%, respectively). Persons who misused opioids were more likely to report condomless sex with partners of negative or unknown HIV status while not durably virally suppressed (11.7% vs 3.4%) than persons who did not misuse opioids.

CONCLUSIONS

Opioid misuse among adults receiving HIV medical care is associated with inadequate ART adherence, insufficient durable viral suppression, and higher risk of HIV transmission to sexual partners.

Types of Polydrug Use Among Spanish Students in Health Sciences

Polydrug use among university students may be a predictor for established patterns of multiple substance use and potentially entail long-term health problems. This study examined the types of polydrug use among Spanish students in health sciences. Undergraduate students (n = 968), aged 18-38 years (M = 21.09 years, SD = 4.10), completed the survey. A percentage of 44.3% of the participants were classified as polydrug users. Type A users (alcohol and cigarettes) made up 17.8% of the participants surveyed, whereas 20.1% were Type B (cannabis with cigarettes and/or alcohol), and a further 5.7% were Type C (cannabis with cigarettes and/or alcohol, plus at least another kind of illegal drug). Type A was the most common type among women, whereas Type C was the most common among men. Type B use was higher among women 18-19 years old than among women 25-29 years old, whereas there were no female Type C users younger than 20 years old. Weekend consumption was higher, than weekday consumption, across all polydrug user types and substances. These results suggest that the prevalence of polydrug use among Spanish students in health sciences was similar to students in other disciplines, with Type B as the most prevalent among healthcare and nonhealthcare students. Taking into account the differences based on gender, age, and time of consumption, a specific approach to the different typologies of polydrug users might be a vital step in the successful development of preventive interventions tailored to the changing reality of psychoactive substance use.

HIV, Drug Injection, and Harm Reduction Trends in Eastern Europe and Central Asia: Implications for International and Domestic Policy

PURPOSE OF REVIEW

Scaling up evidence-based HIV prevention strategies like opioid agonist therapies (OAT), syringe services programs (SSPs), and antiretroviral therapy (ART) to mitigate the harms of drug injection is crucial within Eastern Europe and Central Asia (EECA), the only region globally where HIV incidence and mortality are increasing.

RECENT FINDINGS

Though the proportion of new HIV cases directly attributable to drug injection has recently declined, it remains a critical driver of HIV, especially to sexual partners. Concurrently, scale-up of OAT, SSPs, and ART has remained low, contributing to a volatile HIV epidemic among people who inject drugs (PWID). Despite evidence that drug injection contributes to an evolving HIV epidemic in EECA, coverage of evidence-based harm reduction programs remains substantially below needed targets. Due to a combination of punitive drug laws, ideological resistance to OAT among clinicians and policymakers, and inadequate domestic and international funding, limited progress has been observed in increasing the availability of these programs.

Polydrug use patterns and their impact on relapse among heroin-dependent patients in Shanghai, China

AIMS

To describe the polysubstance use patterns of heroin-dependent patients and to understand the impact of polysubstance use patterns on relapse during the 5 years after completing compulsory rehabilitation programmes.

DESIGN

In this secondary analysis, the baseline data of 503 heroin-dependent patients were linked with their 5-year follow-up data from official records.

SETTING

Four compulsory rehabilitation centres in Shanghai, China.

PARTICIPANTS

A total of 564 heroin-dependent patients who were discharged from Shanghai compulsory rehabilitation facilities in 2007 and 2008 were recruited. Among these, 503 patients with available follow-up records were included in this analysis.

MEASUREMENTS

The baseline measurements included the Addiction Severity Index, the Temperament and Character Inventory and the Medical Outcomes Study Social Support Scale. Relapses after discharge from the compulsory rehabilitation centres were extracted monthly from the official electronic record system. Latent class analysis was used to identify different polysubstance use patterns. Associations between the identified latent classes and heroin use and the factors related to relapse during the 5-year follow-up were analysed with the Cox regression model.

FINDINGS

Three latent classes were identified in this cohort: (1) alcohol polydrug users (APU; 13.7%), (2) low polydrug users (LPU; 76.5%) and (3) amphetamine-type stimulant polydrug users (ASPU; 9.7%). During the 5-year follow-up, 298 heroin patients relapsed, and the three groups showed different relapse rates (ASPU 69.4 versus LPU 60.5 versus APU 44.9%, P = 0.02). The average durations of abstinence for the three groups differed (ASPU 31.27 ± 3.41 months versus LPU 36.77 ± 1.19 months versus APU 42.46 ± 2.81 months, P = 0.02). Multivariate Cox regression analyses found that the LPU [hazard ratio (HR) = 1.63, 1.06-2.51] and ASPU (HR = 2.10, 1.24-3.56) classes were positively associated with the risk of heroin relapse.

CONCLUSION

Polydrug use patterns differ among heroin-dependent patients in compulsory rehabilitation programmes in China. A history of polydrug use may predict heroin relapse risk among patients in those compulsory rehabilitation programmes.

Epidemics of HIV, HCV and syphilis infection among synthetic drugs only users, heroin-only users and poly-drug users in Southwest China

The number of poly-drug users who mix use heroin and synthetic drugs (SD) is increasing worldwide. The objective of this study is to measure the risk factors for being infected with hepatitis C (HCV), human immunodeficiency virus (HIV) and syphilis among SD-only users, heroin-only users and poly-drug users. A cross-sectional study was conducted in 2015 from a national HIV surveillance site in Southwest China, 447 poly-drug, 526 SD-only and 318 heroin-only users were recruited. Poly-drug users have higher drug-use frequency, higher rates of drug-sharing and unsafe sexual acts than other users (p < 0.05). About a third (36.7%) of poly-drug users experienced sexual arousal due to drug effects, which is higher than the rate among other drug users. Poly-drug users had the highest prevalence of HIV (10.5%) and syphilis (3.6%), but heroin-only users had the highest prevalence of HCV (66.0%) (all p < 0.05) among three groups. Logistic regression shows among poly-drug users, having sex following drug consumption and using drugs ≥1/day were the major risk factors for both HIV (Adjusted odds ratio (AOR) = 2.4, 95% CI [1.8–3.4]; 2.3, [1.6–3.1]) and syphilis infection (AOR = 4.1, [2.1–6.9]; 3.9, [1.8–5.4]). Elevated risk of both HIV and syphilis infection have been established among poly-drug users.