Influence of different drugs on HIV risk in people who inject: systematic review and meta-analysis

Examining trends in the incidence of HIV infection among people with a history of drug use to inform an outbreak investigation and response: A retrospective cohort study

BACKGROUND

In the context of an outbreak of HIV among people who inject drugs in Glasgow, Scotland, identified in 2015, our objectives were to: (1) develop epidemiological methods to estimate HIV incidence using data linkage, and (2) examine temporal changes in HIV incidence to inform public health responses.

METHODS

This was a retrospective cohort study involving data linkage of laboratory HIV testing data to identify individuals with a history of drug use. Person-years (PY) and Poisson regression were used to estimate incidence by time period (pre-outbreak: 2000-2010 and 2011-2013; early outbreak: 2014-2016; ongoing outbreak: 2017-2019).

RESULTS

Among 13 484 individuals tested for HIV, 144 incident HIV infections were observed from 2000 to 2019. Incidence rates increased from pre-outbreak periods (1.00/1000 PY (95% confidence interval, CI: 0.60-1.65) in 2000-2010 and 1.70/1000 PY (95% CI: 1.14-2.54) in 2011-2013) to 3.02/1000 PY (95% CI: 2.36-3.86) early outbreak (2014-2016) and 2.35 (95% CI 1.74-3.18) during the ongoing outbreak period (2017-2019). Compared with the pre-outbreak period (2000-2010), the incidence rates were significantly elevated during both the early outbreak (2014-16) (adjusted incidence rate ratio (aIRR) = 2.87, 95% CI: 1.62-5.09, p < 0.001) and the ongoing outbreak periods (2017-19) (aIRR = 2.12, 95% CI: 1.16-3.90, p = 0.015).

CONCLUSIONS

Public health responses helped to curb the rising incidence of HIV infection among people with a history of drug use in Glasgow, but further efforts are needed to reduce it to levels observed prior to the outbreak. Data linkage of routine diagnostic test data to assess and monitor incidence of HIV infection provided enhanced surveillance, which is important to inform outbreak investigations and guide national strategies on elimination of HIV transmission.

HIV-1 latency reversal agent boosting is not limited by opioid use

Opioid use may affect the HIV-1 reservoir and its reversal from latency. We studied 47 virally suppressed people with HIV (PWH) and observed that lower concentration of HIV-1 latency reversal agents (LRAs), used with small molecules that did not reverse latency, synergistically increased the magnitude of HIV-1 reactivation ex vivo, regardless of opioid use. This LRA boosting, which combined a second mitochondria-derived activator of caspases mimetic or low-dose PKC agonist with histone deacetylase inhibitors, generated more unspliced HIV-1 transcription than PMA with ionomycin (PMAi), the maximal known HIV-1 reactivator. LRA boosting associated with greater histone acetylation, modulated surface activation-induced markers, and altered T cell production of TNF-α, IL-2, and IFN-γ. HIV-1 reservoirs in PWH contained unspliced and polyadenylated virus mRNA, the ratios of which were greater in resting than total CD4+ T cells and corrected to 1:1 with PMAi exposure. We characterized treated suppressed HIV-1 infection as a period of inefficient, not absent, virus transcription. Multiply spliced HIV-1 transcripts and virion production did not consistently increase with LRA boosting, suggesting the presence of a persistent posttranscriptional block. LRA boosting can be leveraged to probe mechanisms of an effective cellular HIV-1 latency reversal program.

Hepatitis B virus infection and vaccination among people who use drugs in Xi'an, China

BACKGROUND

While hepatitis B virus (HBV) infection in children has declined dramatically in China due to the vaccination strategy for newborns, HBV infection in high-risk adults is receiving an increasing attention. The number of people who use drugs (PWUD) in China is huge, but their status of HBV infection and vaccination is less reported, especially from large samples. The related knowledge can help decision makers develop the further strategy of HBV prevention and control.

METHODS

A seroepidemiological survey was conducted in all four compulsory isolated detoxification centers (CIDCs) and all eight methadone maintenance treatment (MMT) clinics located in Xi'an, China. All PWUD who were undergoing detoxification or treatment in these settings were included. A questionnaire was designed to obtain the information of HBV vaccination history of participants, and sociodemographic and behavioral data of participants were obtained from the registration records of their respective CIDCs or MMT clinics.

RESULTS

A total of 4705 PWUD participated in the survey. Positive rates of HBsAg (current infection) and HBsAg or anti-HBc (current/past infection) were 5.50% and 58.02%, notably higher than those reported for the general adult population in the same province during the same period. As age increased, the anti-HBc positive rate increased with statistically significant trend. The all-negative for HBsAg, anti-HBc, and anti-HBs accounted for 28.82%. Only 18.49% were identified by the questionnaire as having received HBV vaccine. The logistic regression found that compared with identified vaccinated PWUD, those unsure if having been vaccinated and those identified non-vaccinated had a significantly higher HBV current/past infection rate, with an increasing trend.

CONCLUSION

PWUD are a high-risk adult group of HBV infection in China. Of them, more than half have not received HBV vaccine, and a significant portion are susceptible to HBV. Catch-up vaccination is need for this population to prevent and control HBV transmission.

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.

HIV-1 latency reversal agent boosting is not limited by opioid use

The opioid epidemic may impact the HIV-1 reservoir and its reversal from latency in virally suppressed people with HIV (PWH). We studied forty-seven PWH and observed that lowering the concentration of HIV-1 latency reversal agents (LRA), used in combination with small molecules that do not reverse latency, synergistically increases the magnitude of HIV-1 re-activation ex vivo, regardless of opioid use. This LRA boosting, which combines a Smac mimetic or low-dose protein kinase C agonist with histone deacetylase inhibitors, can generate significantly more unspliced HIV-1 transcription than phorbol 12-myristate 13-acetate (PMA) with ionomycin (PMAi), the maximal known HIV-1 reactivator. LRA boosting associated with greater histone acetylation in CD4+ T cells and modulated T cell activation-induced markers and intracellular cytokine production; Smac mimetic-based boosting was less likely to induce immune activation. We found that HIV-1 reservoirs in PWH contain unspliced and polyadenylated (polyA) virus mRNA, the ratios of which are greater in resting than total CD4+ T cells and can correct to 1:1 with PMAi exposure. Latency reversal results in greater fold-change increases to HIV-1 poly(A) mRNA than unspliced message. Multiply spliced HIV-1 transcripts and virion production did not consistently increase with LRA boosting, suggesting the presence of a persistent post-transcriptional block. LRA boosting can be leveraged to probe the mechanisms of an effective cellular HIV-1 latency reversal program.

PrEP for people who use opioids: A NIDA clinical trials network survey study in Southern U.S. cities where HIV incidence is high

BACKGROUND

People who use opioids (PWUO) are at increased risk for HIV. Pre-exposure prophylaxis (PrEP) is effective but underutilized as HIV prevention among PWUO. This study examined predictors of willingness to take daily oral PrEP and long-acting injectable (LAI) PrEP among PWUO across eight Southern urban cities with high HIV incidence.

METHODS

HIV-negative PWUO (N = 308) seeking services in community-based programs participated in this cross-sectional survey study. Measures included demographics, sexual risk behavior, substance use frequency, and awareness of and willingness to take oral and injectable PrEP. Data were analyzed using mixed-effects models.

RESULTS

Willingness to take daily oral and LAI PrEP was moderately high (69.16% and 62.02%, respectively). Half had heard of PrEP, but only 4% had ever taken it. Only education and condomless vaginal sex predicted willingness to take oral PrEP. Only education predicted willingness to take LAI PrEP. Polysubstance use was prevalent, with substantial proportions of PWUO reporting frequent use of injection drugs (opioids or stimulants, 79.5%), non-injection opioids (73.3%), non-injection stimulants (71.1%), cannabis (62.6%), and hazardous drinking (29.6%). About 20% reported past-year condomless anal sex, and one-third reported past-year condomless vaginal sex.

CONCLUSIONS

PWUO in this study were amenable to PrEP, particularly in light of education and condomless vaginal sex. Careful consideration for matching PrEP messaging to the PWUO audience is needed. PrEP promotion should expand beyond men who have sex with men to include groups such as these predominantly heterosexual, polysubstance-using PWUO with HIV risk who were open to both formulations of PrEP.

Recent increases in crack injection and associated risk factors among people who inject psychoactive drugs in England and Wales

BACKGROUND

Crack use is higher in the United Kingdom (UK) than other European countries. Crack is a stimulant with a short half-life, requiring frequent injection to maintain its euphoric effects, thus increasing the risk of blood borne viruses (BBVs) and skin and soft tissue infections (SSTIs). We assessed trends in the prevalence of current crack injection among people who inject drugs (PWID) and investigated harms and other factors associated with its use.

METHODS

We used data from the annual Unlinked Anonymous Monitoring Survey of PWID, which recruits people who have ever injected psychoactive drugs through specialist services. Participants provide a biological sample and self-complete a questionnaire. We included participants from England and Wales who had injected in the past month. We examined trends in crack injection over time (2011-2021) and factors associated with crack injection using multivariable logistic regression (2019-2021).

RESULTS

The proportion of people self-reporting crack injection in the past month almost doubled between 2011-2020/21, from 34 % (416/1237) to 57 % (483/850). Crack injection was more frequently reported by males than females (adjusted odds ratio 1.46, 95 % confidence interval: 1.15-1.87) and injected alongside heroin (6.67, 4.06-10.97) more frequently than alone. Crack injection was independently associated with injecting equipment sharing (1.64, 1.30-2.07), groin injection (2.03, 1.60-2.56) in the past month, overdosing in the past year (1.90, 1.42-2.53), homelessness in the past year (1.42, 1.14-1.77) and ever having hepatitis C infection (1.64, 1.31-2.06).

CONCLUSION

Crack injection has increased significantly over the past decade in England and Wales. People injecting crack are more likely to engage in behaviours that increase the risk of BBV and SSTI acquisition, such as needle/syringe sharing, groin injection and polydrug use. Harm reduction and drug treatment services should adapt to support the needs of this growing population of people injecting stimulants.

HIV risk perception, pre-exposure prophylaxis (PrEP) awareness, and PrEP initiation intention among women who use drugs

INTRODUCTION

Women who use drugs (WWUD) are prime candidates for pre-exposure prophylaxis (PrEP) due to their elevated risk of acquiring HIV through biological, behavioral, and contextual factors. However, PrEP uptake among WWUD remains low. The relationship between unhealthy drug use and correlates of PrEP uptake in this vulnerable population is not well defined. The purpose of this study is to characterize the relationships between specific types and routes of drug use and several precursors of PrEP uptake among WWUD.

METHODS

The study collected data via a computer-based survey from 233 women living in New York City and Philadelphia who participated in a study designed to develop and pilot a women-focused intervention for PrEP uptake. The sample of cisgender, HIV-negative women were not currently taking PrEP but considered PrEP eligible. This analysis is focused on women's HIV risk perception, PrEP awareness, PrEP initiation intention, and any use of the following drugs: barbiturates, benzodiazepines, crack cocaine, powder cocaine, hallucinogens, heroin, methamphetamines, and prescription opioids.

RESULTS

Within the three months prior to study enrollment, 63.1 % of participants reported any drug use; 42 % reported polydrug use; 19.8 % had injected drugs; 75 % reported getting high or drunk before sex; and 44 % had been enrolled in drug treatment. Of our total sample, 41.2 % perceived themselves at risk for HIV infection, 41.6 % were aware of PrEP prior to the study, and 62.7 % intended to initiate PrEP after they were informed. When compared to other PrEP-eligible women, women who reported prescription opioid use and polydrug use perceived themselves at higher risk for HIV infection and had higher intention to start PrEP. However, they and women who reported injecting drugs also reported lower awareness of PrEP.

CONCLUSION

These findings have implications for increasing education about PrEP and the various modes of HIV exposure to support PrEP uptake in this vulnerable population.

Food Insecurity and Transmission Risks Among People with HIV Who Use Substances

Food insecurity (FI) impacts people with HIV (PWH) and those who use substances (i.e. drugs and alcohol). We evaluated the longitudinal association between FI and HIV transmission risks (unprotected sexual contacts and shared needles/syringes). Among 351 PWH who use substances in Russia, 51.6% reported FI and 37.0% past month injection drug use. The mean number of unprotected sexual contacts in the past 90 days was 13.4 (SD 30.1); 9.7% reported sharing needles/syringes in the past month. We did not find a significant association between mild/moderate FI (adjusted IRR = 0.87, 95% CI 0.47, 1.61) or severe FI (aIRR = 0.84, 95% CI 0.46, 1.54; global p = 0.85) and unprotected sexual contacts. We observed a significant association between severe FI and sharing needles/syringes in the past month (adjusted OR = 3.27, 95% CI 1.45, 7.39; p = 0.004), but not between mild/moderate FI and sharing needles/syringes in the past month (aOR = 1.40,95% CI 0.58, 3.38; p = 0.45). These findings suggest that severe FI could be a potential target for interventions to lower HIV transmission.

Efficacy of Daily Text Messaging to Support Adherence to HIV Pre-Exposure Prophylaxis (PrEP) among Stimulant-Using Men Who Have Sex with Men

Background: Men who have sex with men (MSM) who use stimulants are at increased risk for HIV infection. Adherence to pre-exposure prophylaxis (PrEP) reduces the risk of HIV infection. We evaluated the efficacy of the individualized Texting for Adherence Building (iTAB) intervention for PrEP adherence compared to standard of care (SoC) among 119 MSM who use stimulants (cocaine, methamphetamine and/or other amphetamine) from the California Collaborative Treatment Group 595 randomized control trial.Method: Three ordered levels of PrEP adherence (non-adherence, adequate adherence, and near-perfect adherence) were compared between intervention arms across study visits (weeks 12 and 48) using ordinal logistic regressions.Results: The effect of intervention arm was not significant in the final model; however, there was a 38% decrease in odds (OR = 0.62, p=.023) of having near-perfect adherence (versus non-adherence or adequate adherence) at week 48 compared to week 12, indicating a significant effect of time. In a follow-up analysis examining week 48 only, logistic regression examining PrEP adherence showed that receiving iTAB (compared to SoC) trended toward higher odds of near-perfect adherence relative to adequate adherence (OR = 2.48, p=.061). Higher HIV knowledge resulted in higher odds (OR = 1.72, p=.020) of near-perfect adherence (versus non-adherence or adequate adherence).Conclusion: HIV knowledge may influence PrEP adherence, and most notably, the iTAB intervention may support near-perfect adherence relative to adequate adherence.

Measuring and Addressing Stigma Within HIV Interventions for People Who Use Drugs: a Scoping Review of Recent Research

PURPOSE OF REVIEW

Persistent stigma remains a crucial barrier to HIV prevention and treatment services among people who use drugs (PWUD), particularly for those living with or at-risk for HIV. This scoping review examines the current state of science with regard to approaches for measuring and addressing stigma within HIV interventions among PWUD.

RECENT FINDINGS

Sixteen studies fit the inclusion criteria for this review. Half the studies originated within the USA, and the remaining represented four different regions. Within these studies, stigma was measured using various quantitative, qualitative, and mixed methods. The studies primarily focused on HIV stigma, including value-based judgments, anticipated stigma, and perceived stigma domains. Information-based and skills building approaches at the individual level were the most common for the stigma reduction interventions. Adoption of systematic evaluations is needed for measuring stigma, including intersectional stigma, within HIV interventions among PWUD. Future studies should focus on developing multilevel intersectional stigma reduction interventions for PWUD with and at-risk for HIV globally.

Trends in methamphetamine use, markets and harms in Australia, 2003-2019

INTRODUCTION

To describe trends in methamphetamine use, markets and harms in Australia from 2003 to 2019.

METHODS

Data comprised patterns of use and price from sentinel samples of people who inject drugs and who use MDMA/other illicit stimulants and population-level amphetamine-related police seizures, arrests, hospitalisations, treatment episodes and deaths from approximately 2003 to 2019. Bayesian autoregressive time-series models were analysed for: no change; constant rate of change; and change over time differing in rate after one to three changepoints. Related indicators were analysed post hoc with identical changepoints.

RESULTS

The percentage of people who inject drugs reporting weekly use increased from 2010 to 2013 onwards, while use among samples of people who regularly use ecstasy and other illicit stimulants decreased. Seizures and arrests rose steeply from around 2009/10 to 2014/15 and subsequently plateaued. Price increased ($15.9 [95% credible interval, CrI $9.9, $28.9] per point of crystal per year) from around 2009 to 2011, plateauing and then declining from around 2017. Hospitalisation rates increased steeply from around 2009/10 until 2015/16, with a small subsequent decline. Treatment also increased (19.8 episodes [95% CrI 13.2, 27.6] with amphetamines as the principal drug of concern per 100 000 persons per year) from 2010/11 onwards. Deaths involving amphetamines increased (0.285 per 100 000 persons per year) from 2012 until 2016.

DISCUSSION AND CONCLUSIONS

These findings suggest that problematic methamphetamine use and harms escalated from 2010 to 2012 in Australia, with continued demand and a sustained market for methamphetamine.

HIGH RATE OF HCV REINFECTION AMONG RECENTLY INJECTING DRUG USERS: RESULTS FROM THE TRAP HEP C PROGRAM - A PROSPECTIVE NATIONWIDE, POPULATION-BASED STUDY

BACKGROUND

The Treatment as Prevention for Hepatitis C program started in 2016 in Iceland, offering treatment with direct-acting antivirals to hepatitis C virus (HCV)-infected individuals. Reinfections through injection drug use (IDU) can hamper elimination efforts. We determined reinfection rates (RIR) of HCV among patients in the program.

METHODS

Clinical data were gathered prospectively. The study cohort consisted of HCV-cured patients with an estimated sustained virologic response between February 1st 2016 and November 20th 2018, with follow-up until November 20th 2019. The observation period and time until reinfection was estimated using a single random point imputation method coupled with Monte Carlo simulation. The RIR was expressed as reinfections/100 person-years (PYs).

RESULTS

640 treatments of 614 patients (417 males, mean age 44.3 years) resulted in cure, with 52 reinfections subsequently confirmed in 50 patients (37 males). Follow-up was 672.1 PYs with median time to reinfection of 231.7 days. History of IDU was reported by 523 patients (84.8%) and recent IDU with 220 (34.4%) treatments. Stimulants were the preferred injected drug in 85.5% of patients with history of IDU. The RIR was 7.7/100 PYs. Using multivariate Cox proportional hazards models for interval-censored data, age (HR 0.96, 95% CI 0.94-0.99) and recent IDU (HR 2.91, 95% CI 1.48-5.76) were significantly associated with reinfection risk.

CONCLUSIONS

The RIR is high in a setting of widespread stimulant use, particularly in young people with recent IDU. Regular follow up is important among high-risk populations to diagnose reinfections early and reduce transmission.

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.

Examining a migration-based phenomenon of heroin use in an urban drug scene in Sao Paulo, Brazil

Purpose

Brazil’s street-based drug use is mostly characterized by non-injection psychostimulant (e.g. crack-cocaine) drug use in Brazil, with limited interventions and service availability. Recently, an influx of multi-ethnic migrants within an urban drug scene in Sao Paulo was associated with heroin use, a drug normatively absent from Brazil. The purpose of this paper is to characterize and compare heroin use-related characteristics and outcomes for an attending sub-sample of clients from a large community-based treatment centre (“CRATOD”) serving Sao Paulo’s local urban drug scene.

Design/methodology/approach

All non-Brazilian patients (n = 109) receiving services at CRATOD for 2013–2016 were identified from patient files, divided into heroin users (n = 40) and non-heroin users (n = 69). Based on chart reviews, select socio-demographic, drug use and health status (including blood-borne-virus and other infections per rapid test methods) were examined and bi-variately compared. Multi-variate analyses examined factors independently associated with heroin use.

Findings

Most participants were male and middle-aged, poly-drug users and socio-economically marginalized. While heroin users primarily originated from Africa, they reported significantly more criminal histories, drug (e.g. injection) and sex-risk behaviors and elevated rates of BBV (e.g. Hepatitis C Virus and HIV). A minority of heroin users attending the clinic was provided methadone treatment, mostly for detoxification.

Originality/value

This study documented information on a distinct sample of mostly migration-based heroin users in Sao Paulo, Brazil. Based on the local experience, global migration dynamics can bring changes to established drug use cultures and services, including new challenges for drug use-related related behaviors and therapeutic interventions that require effective understanding and addressing.

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.

Can hepatitis C elimination targets be sustained among people who inject drugs post-2030?

BACKGROUND

In high-income countries, people who inject drugs (PWID) are a priority population for eliminating hepatitis C virus (HCV) by 2030. Despite evidence informing micro-elimination strategies, little is known regarding efforts needed to maintain elimination targets in populations with ongoing acquisition risks. This model-based study investigates post-elimination transmission dynamics of HCV and HIV among PWID under different scenarios where harm reduction interventions and HCV testing and treatment are scaled-down.

METHODS

We calibrated a dynamic compartmental model of concurrent HCV and HIV transmission among PWID in Montréal (Canada) to epidemiological data (2003-2018). We then simulated achieving the World Health Organization elimination targets by 2030. Finally, we assessed the impact of four post-elimination scenarios (2030-2050): 1) scaling-down testing, treatment, opioid agonist therapy (OAT), and needle and syringe programs (NSP) to pre-2020 levels; 2) only scaling-down testing and treatment; 3) suspending testing and treatment, while scaling down OAT and NSP to pre-2020 levels; 4) suspending testing and treatment and maintaining OAT and NSP coverage required for elimination.

RESULTS

Scaling down interventions to pre-2020 levels (scenario 1) leads to a modest rebound in chronic HCV incidence from 2.4 to 3.6 per 100 person-years by 2050 (95% credible interval - CrI: 0.8-7.2). When only scaling down testing and treatment (scenario 2), chronic HCV incidence continues to decrease. In scenario 3 (suspending treatment and scaling down OAT and NSP), HCV incidence and mortality rapidly increase to 11.4 per 100 person-years (95%CrI: 7.4-15.5) and 3.2 per 1000 person-years (95%CrI: 2.4-4.0), respectively. HCV resurgence was mitigated in scenario 4 (maintaining OAT and NSP) as compared to scenario 3. All scenarios lead to decreases in the proportion of reinfections among incident cases and have little impact on HIV incidence and HIV-HCV coinfection prevalence.

CONCLUSION

Despite ongoing transmission risks, HCV incidence rebounds slowly after 2030 under pre-2020 testing and treatment levels. This is heightened by maintaining high-coverage harm reduction interventions. Overall, sustaining elimination would require considerably less effort than achieving it.

Homelessness, unstable housing, and risk of HIV and hepatitis C virus acquisition among people who inject drugs: a systematic review and meta-analysis

BACKGROUND

People who inject drugs (PWID) are at increased risk for HIV and hepatitis C virus (HCV) infection and also have high levels of homelessness and unstable housing. We assessed whether homelessness or unstable housing is associated with an increased risk of HIV or HCV acquisition among PWID compared with PWID who are not homeless or are stably housed.

METHODS

In this systematic review and meta-analysis, we updated an existing database of HIV and HCV incidence studies published between Jan 1, 2000, and June 13, 2017. Using the same strategy as for this existing database, we searched MEDLINE, Embase, and PsycINFO for studies, including conference abstracts, published between June 13, 2017, and Sept 14, 2020, that estimated HIV or HCV incidence, or both, among community-recruited PWID. We only included studies reporting original results without restrictions to study design or language. We contacted authors of studies that reported HIV or HCV incidence, or both, but did not report on an association with homelessness or unstable housing, to request crude data and, where possible, adjusted effect estimates. We extracted effect estimates and pooled data using random-effects meta-analyses to quantify the associations between recent (current or within the past year) homelessness or unstable housing compared with not recent homelessness or unstable housing, and risk of HIV or HCV acquisition. We assessed risk of bias using the Newcastle-Ottawa Scale and between-study heterogeneity using the I2 statistic and p value for heterogeneity.

FINDINGS

We identified 14 351 references in our database search, of which 392 were subjected to full-text review alongside 277 studies from our existing database. Of these studies, 55 studies met inclusion criteria. We contacted the authors of 227 studies that reported HIV or HCV incidence in PWID but did not report association with the exposure of interest and obtained 48 unpublished estimates from 21 studies. After removal of duplicate data, we included 37 studies with 70 estimates (26 for HIV; 44 for HCV). Studies originated from 16 countries including in North America, Europe, Australia, east Africa, and Asia. Pooling unadjusted estimates, recent homelessness or unstable housing was associated with an increased risk of acquiring HIV (crude relative risk [cRR] 1·55 [95% CI 1·23-1·95; p=0·0002]; I2= 62·7%; n=17) and HCV (1·65 [1·44-1·90; p<0·0001]; I2= 44·8%; n=28]) among PWID compared with those who were not homeless or were stably housed. Associations for both HIV and HCV persisted when pooling adjusted estimates (adjusted relative risk for HIV: 1·39 [95% CI 1·06-1·84; p=0·019]; I2= 65·5%; n=9; and for HCV: 1·64 [1·43-1·89; p<0·0001]; I2= 9·6%; n=14). For risk of HIV acquisition, the association for unstable housing (cRR 1·82 [1·13-2·95; p=0·014]; n=5) was higher than for homelessness (1·44 [1·13-1·83; p=0·0036]; n=12), whereas no difference was seen between these outcomes for risk of HCV acquisition (1·72 [1·48-1·99; p<0·0001] for unstable housing, 1·66 [1·37-2·00; p<0·0001] for homelessness).

INTERPRETATION

Homelessness and unstable housing are associated with increased risk of HIV and HCV acquisition among PWID. Our findings support the development of interventions that simultaneously address homelessness and unstable housing and HIV and HCV transmission in this population.

FUNDING

National Institute for Health Research, National Institute on Drug Abuse, National Institute of Allergy and Infectious Diseases, and Commonwealth Scholarship Commission.

Responding to Outbreaks of Human Immunodeficiency Virus Among Persons Who Inject Drugs-United States, 2016-2019: Perspectives on Recent Experience and Lessons Learned

In 2015, a large human immunodeficiency virus (HIV) outbreak occurred among persons who inject drugs (PWID) in Indiana. During 2016-2019, additional outbreaks among PWID occurred across the United States. Based on information disseminated by responding health departments and Centers for Disease Control and Prevention (CDC) involvement, we offer perspectives about characteristics of and public health responses to 6 such outbreaks. Across outbreaks, injection of opioids (including fentanyl) or methamphetamine predominated; many PWID concurrently used opioids and methamphetamine or cocaine. Commonalities included homelessness or unstable housing, previous incarceration, and hepatitis C virus exposure. All outbreaks occurred in metropolitan areas, including some with substantial harm reduction and medical programs targeted to PWID. Health departments experienced challenges locating case patients and contacts, linking and retaining persons in care, building support to strengthen harm-reduction programs, and leveraging resources. Expanding the concept of vulnerability to HIV outbreaks and other lessons learned can be considered for preventing, detecting, and responding to future outbreaks among PWID.

Recent HIV testing and associated factors among people who use drugs in Cambodia: a national cross-sectional study

OBJECTIVE

To estimate the prevalence of HIV testing and examine factors associated with recent HIV testing among people who use drugs (PWUD) in Cambodia.

DESIGN

Cross-sectional study.

SETTING

Twelve major provinces with a high burden of HIV and drug use in Cambodia.

PARTICIPANTS

This study included 1677 PWUD recruited using a peer-based social network recruitment method. Participants' selection criteria included being at least 18 years old and using any illicit drugs via any administration routes in the past 12 months.

PRIMARY OUTCOME MEASURE

Recent HIV testing, defined as having an HIV test in the past 6 months.

RESULTS

The median age of the participants was 28 (IQR 22-34) years, and 56.6% were men. The prevalence of lifetime and recent HIV testing was 70.7% and 42.9%, respectively. After adjustment in multivariable logistic regression analysis, recent HIV testing remained positively associated with being female (adjusted OR (AOR) 1.55, 95% CI 1.18 to 2.04) or third gender identity (AOR 2.06, 95% CI 1.11 to 3.80), having ever been to a drug rehabilitation centre (AOR 1.60, 95% CI 1.13 to 2.29), having used any HIV services in the past 6 months (AOR 7.37, 95% CI 5.61 to 9.69), having received HIV education in the past 3 months (AOR 3.40, 95% CI 2.63 to 4.40) and having self-perception of higher HIV risk (AOR 1.81, 95% CI 1.19 to 2.73).

CONCLUSIONS

Recent HIV test uptake among PWUD in Cambodia was suboptimal. This study highlights the roles of outreach HIV education and services in promoting regular HIV testing among PWUD. Strengthening the coordinated effort of government agencies and local civil society organisations to prioritise expanding community-based peer-driven interventions to reach out to this hidden population is warranted.

Reducing Risky Drug Use Behaviors by Enrolling Syringe Exchange Registrants in Methadone Maintenance

Referral of syringe exchange registrants with opioid use disorder to agonist treatment provides a pathway to further reduce drug use risk behaviors. Objective: This study evaluates the drug use risk reduction benefits of enrolling syringe exchange registrants in methadone maintenance, and the impact of continued illicit drug use on risk reduction. Method: Baltimore Needle Exchange Program (BNEP) registrants (n = 210) participated in a parent study evaluating treatment initiation strategies for methadone maintenance and were followed for six months. The Risk Assessment Battery (RAB; Metzger, 1993) was administered monthly to evaluate drug use risks; urinalysis testing was conducted weekly. Results: Treatment enrollment reduced drug use risk behaviors, and longer treatment episodes resulted in additional, though modest, risk reduction. Use of opioids or cocaine in treatment diminished risk-reduction benefits, though drug use risks declined over time and remained well below baseline levels. Conclusions: These findings demonstrate that methadone maintenance enhances the well-known risk-reduction benefits of syringe exchange participation. Improving coordination between syringe exchanges and treatment facilities may enhance the public health.

Risk factors associated with infection of blood-borne virus among people who used methamphetamine

BACKGROUND

The surge of methamphetamine use has been a complicating factor compounding the steeply increasing number of drug overdose deaths in the U.S. Infection from blood-borne viruses including hepatitis B virus (HBV), hepatitis C virus (HCV) and HIV, related to methamphetamine use continue to grow. This study aims to examine the risk factors associated with HBV, HCV and HIV among people who used methamphetamine.

METHODS

People who ever used methamphetamine were identified from five National Health and Nutrition Examination Survey (NHANES) cohorts, 2007 to 2016. The outcome was either positive or negative for blood-borne viruses as identified from laboratory tests. Weighted statistics for the combined ten years of data were calculated by multiplying the weighted variable for laboratory measurements by 0.2. We examined the association of sexual activities (sexual partners, sexual identity), drug use behaviors (poly-drug use, injection drug use, frequency of drug use, age started using methamphetamine), demographics, and socio-economic status with blood-borne viruses using bivariate and multivariable logistic regression models.

RESULTS

There were 1132 participants representing approximately 11,996,319 persons who ever used methamphetamine in the U.S. Blood-borne viruses' positive rate was 13.0 per 100,000. Multivariable logistic regression analyses showed significant associations of blood-borne infections with age 40-49 years (vs. age 20-29 years, adjusted odds ratio 4.77, 95% CI 1.11-20.55), age 50-59 years (vs. age 20-29 years, 10.25, 2.40-43.82), living within poverty index 1-1.9 (vs. poverty index > = 2, 2.55; 1.19-5.49), living below the poverty threshold (vs. poverty index > = 2, 2.55; 1.11-5.86), having lower than high school education (vs. equal or higher than high school education, 3.13; 1.51-6.46), sexual identity as other than heterosexual (vs. heterosexual, 5.60; 1.72-18.28), using methamphetamine and heroin and cocaine (vs. using methamphetamine alone, 4.24; 1.06-16.92), injection drug use (vs. no injection drug use, 3.15; 1.61-6.16), and started using methamphetamine at age above 25 (vs. started using methamphetamine at age between 10 and 17, 2.09; 1.01-4.35).

CONCLUSIONS

Among people who use methamphetamine, those who use polysubstance, or who inject substances, are in urgent need for vaccination and interventions to avoid further harm from blood borne infections.

Hepatitis B, hepatitis C and HIV prevalence and related sexual and substance use risk practices among key populations who access HIV prevention, treatment and related services in South Africa: findings from a seven-city cross-sectional survey (2017)

Background

People who use drugs including people who inject drugs (PWUD/ID), sex workers (SWs) and men who have sex with men (MSM) are at increased risk of HIV and viral hepatitis infection. Limited epidemiological data on the infections exists in key populations (KPs) in South Africa. We investigated the prevalence of hepatitis B (HBV), hepatitis C (HCV) and HIV and selected risk factors among these KPs to inform effective responses.

Methods

We used convenience sampling to recruit a targeted 3500 KPs accessing HIV-related health services across Cape Town (SWs, MSM, PWUD/ID), Durban (SWs, PWUD/ID), Pietermaritzburg (SWs), Mthatha (SWs), Port Elizabeth (SWs), Johannesburg (MSM) and Pretoria (MSM and PWUD/ID) into a cross-sectional survey. An interviewer questionnaire to assess socio-demographic characteristics, drug use and sexual risk practices, was administered. HBV surface antigen (HBsAg); HCV antibody, viral load and genotype, and HIV antibody, was tested.

Results

Among the 3439 people included in the study (1528 SWs, 746 MSM, 1165 PWUD/ID) the median age was 29 years, most participants were black African (60%), and 24% reported homelessness. 82% reported substance use in the last month, including alcohol (46%) and heroin (33%). 75% were sexually active in the previous month, with condom use at last sex at 74%. HIV prevalence was 37% (highest among SWs at 47%), HBsAg prevalence 4% (similar across KPs) and HCV prevalence was 16% (highest among PWUD/ID at 46%).

Conclusions

HBV, HCV and HIV pose a health burden for KPs in South Africa. While HIV is key for all included KPs, HCV is of particular importance to PWUD/ID. For KPs, HBV vaccination and behavioural change interventions that support consistent condom and lubricant access and use are needed. Coverage of opioid substitution therapy and needle and syringe services, and access to HCV treatment for PWUD/ID need to be expanded.

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.

Syphilis infection among people who use and inject drugs in Cambodia: a cross-sectional study using the respondent-driven sampling method

This cross-sectional study explored the prevalence and correlates of syphilis infection among people who use and inject drugs (PWUD/PWID) in Cambodia. Data were collected in 2017 from 1,677 PWUD/PWID living in the capital city of Phnom Penh and 11 other major provinces using the respondent-driven sampling method. The SD Bioline HIV/Syphilis Duo test was used to determine human immunodeficiency virus (HIV) and current or past syphilis infection. A multivariable logistic regression analysis was conducted to identify risk factors associated with current or past syphilis infection. The prevalence of current or past syphilis infection was 3.8% (95% confidence interval = 2.4-4.6). After adjustment, current or past syphilis infection remained positively associated with being female, living on the streets, having an average monthly income of US$100-299, having transactional sex in the past three months, and having been to a rehabilitation centre in the past 12 months. Current or past syphilis infection was negatively associated with having attained at least high school level of formal education. The findings indicate vulnerability to syphilis infection among PWUD/PWID in Cambodia, particularly among subpopulations who are more marginalized. Syphilis prevention and control programmes should be systematically integrated into HIV and sexually transmitted infection policy and services in the country.

HIV prevalence among people who inject drugs (PWID) and related factors in Iran: a systematic review, meta-analysis and trend analysis

AIMS

In Iran, injecting drug use has been the major route of human immunodeficiency virus (HIV) transmission. In order to control the HIV epidemic, a harm reduction program was initiated and has been expanded in recent years. The aim of this study was to provide an updated estimate of HIV prevalence among people who inject drugs (PWID) in Iran, investigate prevalence differences over time and assess prevalence correlates.

DESIGN

A comprehensive systematic review was undertaken in the international, regional and national bibliographic databases in November 2018 and extensive contacts with authors were made. For studies conducted before 2005, we used data from a previous published systematic review.

SETTING

All studies conducted in Iran were included. Recruitment settings included anywhere except studies conducted in infectious diseases wards or HIV counseling centers.

PARTICIPANTS

PWID with any definition utilized in the studies. Thirty-six studies were included, which were conducted in 24 of 31 provinces with a sample size of 22 160 PWID.

MEASUREMENTS

We included studies that had performed HIV testing and had a confirmed diagnosis of HIV through repeating the enzyme-linked immunosorbent assay (ELISA) or Western immunoblot assay (WB). Pooled prevalence of HIV was calculated for the total sample and for different subgroups, by available socio-demographic and behavioral factors. For assessing the trend of HIV prevalence over time, a linear meta-regression model was fitted separately for before 2007 and during 2007 and afterwards.

FINDINGS

The pooled prevalences of HIV before 2007 and in 2007 and afterwards were 14.3% [95% confidence interval (CI) = 9.8-18.9] and 9.7% (95% CI = 7.6-11.9), respectively. HIV prevalence increased until 2005-06 and then slowly declined until 2009-10, which was not significant. Prevalence of HIV was significantly higher in PWID above age 25 years, and in those with history of imprisonment and history of needle/syringe-sharing. HIV prevalence was higher in men than in women, but the difference was insignificant.

CONCLUSION

The prevalence of HIV among people who inject drugs in Iran decreased after 2006 which could, at least in part, be attributed to the development of extensive harm reduction programs in the country.

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.

Responding to global stimulant use: challenges and opportunities

We did a global review to synthesise data on the prevalence, harms, and interventions for stimulant use, focusing specifically on the use of cocaine and amphetamines. Modelling estimated the effect of cocaine and amphetamine use on mortality, suicidality, and blood borne virus incidence. The estimated global prevalence of cocaine use was 0·4% and amphetamine use was 0·7%, with dependence affecting 16% of people who used cocaine and 11% of those who used amphetamine. Stimulant use was associated with elevated mortality, increased incidence of HIV and hepatitis C infection, poor mental health (suicidality, psychosis, depression, and violence), and increased risk of cardiovascular events. No effective pharmacotherapies are available that reduce stimulant use, and the available psychosocial interventions (except for contingency management) had a weak overall effect. Generic approaches can address mental health and blood borne virus infection risk if better tailored to mitigate the harms associated with stimulant use. Substantial and sustained investment is needed to develop more effective interventions to reduce stimulant use.

Prevalence and risk factors of HIV infection among people who inject drugs in Cambodia: findings from a national survey

BACKGROUND

Globally, people who inject drugs (PWID) continue to be among the most vulnerable populations to acquire infection of human immunodeficiency virus (HIV). The most recent national survey found that nearly a quarter of PWID in Cambodia were infected with HIV in 2012. The aim of this study is to estimate the current prevalence of and factors associated with HIV infection among PWID in Cambodia.

METHODS

This national integrated biological and behavioral survey was conducted from June to December 2017. Participants were recruited from the capital city and 11 major provinces using the respondent driven sampling method. Face-to-face interviews were conducted using a structured questionnaire, and blood samples were collected for HIV, syphilis, and hepatitis C virus (HCV) testing. Multiple logistic regression analysis was conducted to identify risk factors for HIV infection. All analyses were estimated with sampling weights that corrected for non-response and sample design.

RESULTS

A total of 310 PWID participated in the study, and the mean age was 31.8 years (SD = 7.8). The prevalence of HIV was 15.2%. More than half (57.4%) of the HIV-positive participants were co-infected with HCV, and 44.7% were not aware of their HIV status prior to this study. After adjustment for other covariates, HIV infection remained positively associated with being female (AOR = 1.88, 95% CI = 1.03-4.04), being in the older age group of ≥35 (AOR = 2.99, 95% CI 1.33-9.22), being widowed, divorced or separated (AOR = 2.57, 95% CI = 1.04-6.67), living on the streets (AOR = 2.86, 95% CI 1.24-4.37), and HCV infection (AOR = 3.89, 95% CI 1.86-1.15). The HIV infection remained negatively associated with having higher level of formal education of ≥10 years (AOR = 0.44, 95% CI 0.13-0.83) and higher average income of ≥US$200 per month (AOR = 0.20, 95% CI = 0.05-0.74).

CONCLUSIONS

The prevalence of HIV among PWID in Cambodia remains high, but is reducing compared with the 24.8% reported in the 2012 national survey. Findings from this study provide critical information for tailoring interventions based on identified vulnerabilities and risk factors for HIV. Our findings underline the importance of socio-structural factors in HIV epidemiology among PWID in Cambodia, which require mitigation.

Prevalence and correlates of HIV infection among people who use drugs in Cambodia: a cross-sectional survey using respondent driven sampling method

Background

Most of studies on the relationship between drug use and HIV have focused largely on people who inject drugs. Non-injecting drug use is much more common than injecting drug use, and although it can also predispose people to HIV infection, it is not widely explored. We therefore conducted this study to explore the prevalence of HIV and identify risk factors for HIV infection among people who use non-injecting drugs (PWUD) in Cambodia.

Methods

This cross-sectional study was conducted in 2017. The Respondent Driven Sampling method was used to recruit the study participants who were interviewed face-to-face using a structured questionnaire. Blood samples were collected for HIV and syphilis testing. A multivariable logistic regression analysis was conducted to identify risk factors associated with HIV infection.

Results

In total, 1367 PWUD were included in this study, whose mean age was 28.0 (SD = 7.7) years. The majority (95.1%) of the participants used methamphetamine. The prevalence of HIV was 5.7, and 35.2% of the identified HIV-positive PWUD were not aware of their status prior to the survey. After adjustment for other covariates, HIV infection remained significantly associated with being in the age group of ≥35 (AOR = 2.34, 95% CI = 1.04–6.11), having lower level of formal education of ≤ 6 years (AOR = 2.26, 95% CI = 1.04–5.15), living on the streets (AOR = 2.82, 95% CI = 1.10–7.23), perception that their HIV risk was higher as compared to that of the general population (AOR = 3.18, 95% CI = 1.27–8.62), having used injecting drugs in lifetime (AOR = 3.8, 95% CI = 1.36–4.56), and having cuts or sores around the genital area in the past 12 months (AOR = 3.42, 95% CI = 1.09–6.33).

Conclusions

The prevalence of HIV among PWUD in this study was more than 10 times higher than the prevalence in the general adult population. The findings reveal a higher vulnerability to HIV infection among specific sub-populations of PWUD, such as those who are homeless, who may benefit from tailored interventions that respond to their specific needs. To enhance HIV case finding, stratification of PWUD to facilitate HIV risk profiling based on socio-economic profiles and drug injection history is recommended.

Syndemic and Synergistic Effects of Intimate Partner Violence, Crystal Methamphetamine, and Depression on HIV Sexual Risk Behaviors among Women Who Inject Drugs in Indonesia

Women who inject drugs are disproportionately affected by co-occurring intimate partner violence (IPV), poor mental health, and substance use. Less is known about the potentially synergistic effects of these factors on women's HIV risk behavior, and no known studies in Asia examine these relationships. This study assessed the additive and interactive effects of exposure to syndemic IPV, depressive symptoms and non-injection crystal methamphetamine (crystal meth) on HIV sexual risk behaviors in the largest cross-sectional sample of women who inject drugs in Indonesia. Seven hundred thirty-one women aged ≥ 18 years, injecting drugs in the preceding 12 months, and residing in Greater Jakarta or Bandung, West Java, were recruited using respondent-driven sampling (RDS). Twenty-six percent of women experienced concurrent IPV, crystal meth use and depressive symptoms. In multivariate logistic regressions controlling for sociodemographic confounders, all three factors were significantly positively associated with sexual risk outcomes. In adjusted marginal effects models, concurrent experience of IPV, crystal meth use and depressive symptoms was associated with increases in the prevalence of HIV risk outcomes: STI symptomatology (from 12% to 60%), inconsistent condom use (from 3% to 22%), and engagement in survival sex work (from 6% to 25%). Statistically significant interaction was detected on both multiplicative and additive scales. Specifically, an interaction was observed on the multiplicative scale between depressive symptoms and crystal meth on STI symptomatology (OR = 2.61; 95% CI = 1.24, 5.48; p = 0.011). There was also evidence of additive interaction, with most observed joint effects being greater than additive. Specifically, significant positive interaction was observed between IPV and crystal meth on inconsistent condom use (AP = 0.38, p < 0.05); depressive symptoms and crystal meth on STI symptomatology (RERI = 2.04, p < 0.001; AP = 0.61, p < 0.001) and survival sex (RERI = 1.20, p < 0.01; AP = 0.53, p < 0.01); and IPV and depressive symptoms on STI symptomatology (RERI = 3.01, p < 0.01; AP = 0.52, p < 0.001; S = 2.70, p < 0.01) and survival sex (RERI = 1.21, p < 0.05; AP = 0.40, p < 0.05). This study provides new empirical evidence showing that the syndemic conditions of IPV, depressive symptoms and crystal meth consumption interact synergistically to increase women's HIV risk. Interventions that consider the full scope of syndemic vulnerabilities, rather than addressing individual conditions separately, may be essential.

Incarceration history and risk of HIV and hepatitis C virus acquisition among people who inject drugs: a systematic review and meta-analysis

BACKGROUND

People who inject drugs (PWID) experience a high prevalence of incarceration and might be at high risk of HIV and hepatitis C virus (HCV) infection during or after incarceration. We aimed to assess whether incarceration history elevates HIV or HCV acquisition risk among PWID.

METHODS

In this systematic review and meta-analysis, we searched MEDLINE, Embase, and PsycINFO databases for studies in any language published from Jan 1, 2000 until June 13, 2017 assessing HIV or HCV incidence among PWID. We included studies that measured HIV or HCV incidence among community-recruited PWID. We included only studies reporting original results and excluded studies that evaluated incident infections by self-report. We contacted authors of cohort studies that met the inclusion or exclusion criteria, but that did not report on the outcomes of interest, to request data. We extracted and pooled data from the included studies using random-effects meta-analyses to quantify the associations between recent (past 3, 6, or 12 months or since last follow-up) or past incarceration and HIV or HCV acquisition (primary infection or reinfection) risk among PWID. We assessed the risk of bias of included studies using the Newcastle-Ottawa Scale. Between-study heterogeneity was evaluated using the I2 statistic and the P-value for heterogeneity.

FINDINGS

We included published results from 20 studies and unpublished results from 21 studies. These studies originated from Australasia, western and eastern Europe, North and Latin America, and east and southeast Asia. Recent incarceration was associated with an 81% (relative risk [RR] 1·81, 95% CI 1·40-2·34) increase in HIV acquisition risk, with moderate heterogeneity between studies (I2=63·5%; p=0·001), and a 62% (RR 1·62, 95% CI 1·28-2·05) increase in HCV acquisition risk, also with moderate heterogeneity between studies (I2=57·3%; p=0·002). Past incarceration was associated with a 25% increase in HIV (RR 1·25, 95% CI 0·94-1·65) and a 21% increase in HCV (1·21, 1·02-1·43) acquisition risk.

INTERPRETATION

Incarceration is associated with substantial short-term increases in HIV and HCV acquisition risk among PWID and could be a significant driver of HCV and HIV transmission among PWID. These findings support the need for developing novel interventions to minimise the risk of HCV and HIV acquisition, including addressing structural risks associated with drug laws and excessive incarceration of PWID.

FUNDING

Engineering and Physical Sciences Research Council, National Institute for Health Research, National Institutes of Health.

Intimate relationships and patterns of drug and sexual risk behaviors among people who inject drugs in Kazakhstan: A latent class analysis

BACKGROUND

Multiple drug and sexual risk behaviors among people who inject drugs (PWID) in intimate relationships increase the risk of HIV and HCV transmission. Using data on PWID in intimate partnerships in Almaty, Kazakhstan, this study performed latent class analysis (LCA) on drug and sexual risk behaviors and estimated associations between dyadic relationship factors and membership in latent classes.

METHODS

LCA was performed on a sample of 510 PWID (181-females/FWID, 321-males/MWID) to identify levels of drug and sexual risk behaviors. Generalized structural equation modeling with multinomial regressions estimated associations between relationship factors (length risk reduction communication, risk reduction self-efficacy) and class membership after adjusting for substance use severity, overdose, depression, binge drinking, intimate partner violence, structural factors, and sociodemographic characteristics. Models were sex-stratified to include FWID and PWID.

RESULTS

A 3-class model best fit the data and consisted of low, medium, and high-risk classes. GSEM found that greater injection self-efficacy was associated with a lower likelihood of membership in the high-risk class for PWID and FWID. For MWID, greater length of the relationship was associated with a lower likelihood of membership in the medium-risk class. Greater relationship communication was associated with increased risk of membership in the high-risk latent class for MWID.

CONCLUSIONS

Future research must investigate if increasing risk reduction and safe sex self-efficacy could reduce drug and sexual risk behaviors and HIV transmission among PWID and their intimate partners. Interventions are needed that reduce power inequities within relationships as a method of increasing self-efficacy, particularly among women.

Pharmacotherapy for amphetamine dependence: A systematic review

BACKGROUND

Demand for treatment for amphetamine use is increasing internationally. Establishing effective pharmacotherapy provides broader treatment options for people who are dependent on amphetamine and may encourage engagement in evidence-based behavioral treatment. This study aimed to identify medicines that have potential in improving treatment outcomes for people who are dependent on amphetamines.

METHODS

Medline, PsycINFO, Embase and the Cochrane Database of Systematic Reviews were searched from 1997 to 2012 and again from 2013 to 2016. Studies on medications for amphetamine/methamphetamine dependence treatment were selected and assessed by two independent researchers. A meta-narrative review approach was used to synthesize results.

RESULTS

A total of 49 studies investigating 20 potential pharmacotherapies were eligible for inclusion. Of these, 35 studies related to 33 level II quality randomized controlled trials (RCTs). Five medications were subject to multiple RCTs. Four of these medicines demonstrated some limited evidence of benefit for reducing amphetamine use: methylphenidate (as reported in three studies), bupropion (in three studies), modafinil (two studies), and naltrexone (one study). Four RCTs of dexamphetamine suggest its benefit on secondary outcomes such as treatment retention, but not for reducing amphetamine use. Six other medicines indicate the potential for efficacy, but the number of studies is too small to draw conclusions.

CONCLUSIONS

No medicine has as yet demonstrated sufficient, consistent evidence of effectiveness to support its use in routine treatment. High study drop-out and poor medication adherence limits the strength of evidence and raises important clinical questions about how to improve treatment engagement and outcomes.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

HIV Prevalence, Knowledge, Attitudes, and Practices Among Polydrug Users in Brazil: A Biological Survey Using Respondent Driven Sampling

Brazil has a concentrated HIV epidemic among key populations. In 2009, the Ministry of Health conducted a survey in 10 Brazilian cities aiming to estimate HIV prevalence, knowledge, and associated risk behaviors of polysubstance users (PSU). Using Respondent Driven Sampling (RDS), 3449 PSU were recruited, answered an Audio-Computer Self Assisted Interview (ACASI) and were tested for HIV and syphilis. Analyses were weighted by individual's social network size generated on RDSAT. Pooled HIV prevalence was 5.8% but varied across cities. Most PSU were male, non-white, without income, unemployed, with low levels of education. Overall, 12.0% used injectable drugs, 48.7% had sex with occasional partners and 46.4% engaged in commercial sex. A majority received free condoms (71.4%) but 76.7% exhibited inconsistent condom use. Findings can support policies aiming to improve health care and preventive interventions tailored to this population that remains at high risk of acquiring and transmitting HIV/STI in multiple scenarios.

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

Non-medical drug injection is a major risk factor for HIV infection in Russia and Estonia. Multiple drug use (polydrug) has further been associated with increased harms. We compared HIV, injecting and sexual risk associated with polydrug use among people who injected drugs (PWID) in 2012–2013 in Kohtla-Järve (Estonia, n = 591) and St Petersburg (Russia, n = 811). Using latent class analysis, we identified five (poly)drug classes, the largest consisting of single-drug injectors among whom an opioid was the sole drug injected (56% of PWID). The four remaining polydrug classes included polydrug-polyroute injectors who injected and used opiates and stimulants (9%), opiate-stimulant poly-injectors who injected amphetamine-type-stimulants with a primary opiate (7%) and opiate-opioid poly-injectors who injected opioids and opiates (16%). Non-injection stimulant co-users were injectors who also used non-injection stimulants (12%). In multivariable multinomial regressions, all four polydrug classes were associated with greater injection risks than single-drug injection, while opiate-stimulant and opiate-opioid poly-injection were also associated with having multiple sex partners. Riskier behaviours among polydrug-injectors suggest increased potential for transmission of blood-borne and sexually-transmitted infections. In addition to needles/syringes provision, services tailored to PWID drug and risk profiles, could consider drug-appropriate treatment and sexual risk reduction strategies to curb HIV transmission.

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.

Patterns of HIV testing, drug use, and sexual behaviors in people who use drugs: findings from a community-based outreach program in Phnom Penh, Cambodia

Background

People who use drugs are an important priority for HIV programs. However, data related to their utilization of HIV services are limited. This paper reports patterns of HIV testing, drug use, and risk and service perception among people who use drugs. Study participants were receiving HIV and harm reduction services from a community-based program in Phnom Penh, comprised of itinerant peer-led outreach and static drop-in centers.

Methods

This was a mixed-methods study conducted in 2014, comprising of a quantitative survey using a structured questionnaire, followed by two focus group discussions among a sub-sample of survey participants. Participants were recruited from hotspots in five HIV high-burden communes using a two-stage cluster sampling method. Quantitative descriptive analyses and qualitative thematic analyses were performed.

Results

This study included 151 people who use drugs with a mean age of 31.2 (SD = 6.5) years; 77.5% were male and 39.1% were married. The most common drugs used were methamphetamines (72.8%) and heroin (39.7%), and 38.0% injected drugs in the past 3 months. Overall, 83.3% had been tested for HIV in the past 6 months, of whom 62.5% had been tested by peers through community-based outreach. However, there were ongoing HIV risks: 37.3% were engaging in sex on drugs, only 35.6% used a condom at last sexual intercourse, and 10.8% had had a sexually transmitted infection in the last 6 months. Among people who reported injecting drugs in the past 3 months, 27.5% reported re-using needles/syringes. Almost half (46.5%) perceived themselves as being at lower risk of HIV compared to the general population. Qualitative results contextualized the findings of low perception of HIV risks and suggested that although services were often unavailable on weekends, at night, or during national holidays, peer-led community-based outreach was highly accepted.

Conclusions

A peer-led community-based approach was effective in reaching people who use drugs with HIV and harm reduction interventions. To mitigate ongoing HIV risks, expanding access to combination prevention interventions and implementing strategies to enable people who use drugs to objectively assess their HIV risks are required. Additionally, community-based programs should collect data along the care continuum, to enable decentralized tracking of progress towards 90–90–90 goals at local levels.

Effects of environmental enrichment on self-administration of the short-acting opioid remifentanil in male rats

BACKGROUND

Opioid abuse is a major problem around the world. Identifying environmental factors that contribute to opioid abuse and addiction is necessary for decreasing this epidemic. In rodents, environmental enrichment protects against the development of low dose stimulant self-administration, but studies examining the effect of enrichment and isolation (compared to standard housing) on the development of intravenous opioid self-administration have not been conducted. The present study investigated the role of environmental enrichment on self-administration of the short-acting μ-opioid remifentanil.

METHODS

Rats were raised in an enriched condition (Enr), standard condition (Std), or isolated condition (Iso) beginning at 21 days of age and were trained to lever press for 1 or 3 μg/kg/infusion remifentanil in young adulthood. Acquisition of self-administration and responding during increasing fixed ratio requirements were assessed, and a dose-response curve was generated.

RESULTS

In all phases, Enr rats lever pressed significantly less than Std and Iso rats, with Enr rats pressing between 9 and 40% the amount of Iso rats. Enr rats did not acquire remifentanil self-administration when trained with 1 μg/kg/infusion, did not increase responding over increasing FR when trained at either dose, and their dose-response curves were flattened compared to Std and Iso rats. When expressed as economic demand curves, Enr rats displayed a decrease in both essential value (higher α) and reinforcer intensity (Q 0) compared to Std and Iso rats at the 1 μg/kg/infusion training dose.

CONCLUSION

Environmental enrichment reduced remifentanil intake, suggesting that social and environmental novelty may protect against opioid abuse.

A large proportion of people who inject drugs are susceptible to hepatitis B: Results from a bio-behavioural study in eight German cities

BACKGROUND

People who inject drugs (PWID) are at high risk of hepatitis B virus (HBV) infection by sharing needles and drug use paraphernalia. In Germany, no routine surveillance of HBV prevalence and vaccination coverage among PWID exists.

METHODS

Socio-demographic and behavioural data were collected between 2011 and 2014 through face-to-face interviews, during a bio-behavioural survey of PWID recruited in eight German cities. Dried blood spots (DBS) prepared with capillary blood were tested for HBV markers. Factors associated with past/current HBV infection and vaccination status were analysed by univariable and multivariable analysis using logistic regression. The validity of self-reported HBV infection and vaccination status was analysed by comparison to the laboratory results.

RESULTS

Among 2077 participants, the prevalence of current HBV infection was 1.1%, of past HBV infection was 24%, and of vaccine-induced HBV antibodies was 32%. No detectable HBV antibodies were found in 43%. HBV infection status was significantly associated with study city, age, years of injecting, use of stimulants, migration status, and homelessness; HBV vaccination status was significantly associated with study city, age, and level of education. Correct infection status was reported by 71% and correct vaccination status by 45%.

CONCLUSIONS

HBV seroprevalence among PWID was about five times higher than in the general population in Germany, confirming PWID as an important risk group. Targeted information campaigns on HBV and HBV prevention for PWID and professionals in contact with PWID need to be intensified. Routinely offered HBV vaccination during imprisonment and opioid substitution therapy would likely improve vaccination rates among PWID.

Barriers to Access to Sterile Syringes as Perceived by Pharmacists and Injecting Drug Users: Implications for Harm Reduction in Lebanon

BACKGROUND

Access to sterile syringes to injecting drug users (IDU) reduces sharing behavior and prevents the transmission of HIV.

OBJECTIVES

To describe the barriers to access to sterile syringes for IDUs in Lebanon from the perspectives of pharmacists and IDUs.

METHODS

in this qualitative study conducted in Lebanon, data were collected from 72 syringe purchase tests at pharmacies, 64 interviewees with pharmacists and 2 focus groups with injecting drug users. Two independent researchers analyzed the verbatim transcripts.

RESULTS

Results revealed that pharmacists often deny access to sterile syringes to IDUs who are frequently stigmatized and intimidated at pharmacies. While no large gender differences in pharmacists' attitudes and practices were observed, inequalities in syringe access were noticed with men IDUs more often denied purchase. Pharmacists had several barriers to sell syringes to IDUs including fear of disease spread, increased drug use, inappropriately discarded syringes, staff and customer safety, and business concerns. IDUs had several challenges to purchase syringes including stigmatization, intimidation, physical harassment, concern to reveal identity, fear of arrest and syringe price abuse.

CONCLUSIONS

Identifying the barriers to and facilitators of access to sterile syringes to IDUs is important to guide the development of efficient policies. Findings implicate the importance of empowering IDUs to purchase syringes at pharmacies through reducing the negative attitude towards IDUs and strengthening pharmacists' role in the promotion of health of IDUs. Findings also suggest that the habit of syringe sharing would decrease if the legal and cultural barriers to access are reduced.

Willingness to use pre-exposure prophylaxis for HIV prevention among men who have sex with men in Malaysia: Findings from an online survey

Objective

We examined willingness to use pre-exposure prophylaxis (PrEP) for HIV prevention among men who have sex with men (MSM) in Malaysia.

Methods

An online survey of 990 MSM was conducted between March and April 2016. Eligibility criteria included being biological male, Malaysian citizen, 18 years of age or above, identifying as MSM, and being HIV negative or unknown status. Participants’ demographics, sexual and drug use behaviors, attitudes towards PrEP, and preferences regarding future access to PrEP were collected. Bivariate analysis and logistic regression were performed to determine factors associated with willingness to use PrEP.

Results

Fewer than half of participants (44%) knew about PrEP before completing the survey. Overall, 39% of the sample were willing to take PrEP. Multivariate logistic regression indicated that Malay men (AOR: 1.73, 95% CI:1.12, 2.70), having 2 or more male anal sex partners in the past 6 months (AOR: 1.98, 95% CI: 1.29, 3.05), previous knowledge of PrEP (AOR: 1.40, 95%CI: 1.06, 1.86), lack of confidence in practising safer sex (AOR: 1.36, 95% CI: 1.02, 1.81), and having ever paid for sex with a male partner (AOR: 1.39, 95% CI: 1.01, 1.91) were independently associated with greater willingness to use PrEP, while men who identified as heterosexual were less willing to use PrEP (AOR, 0.36, 95% CI: 0.13, 0.97). Majority of participants preferred to access PrEP at affordable cost below 100 Malaysian Ringgit (USD25) per month from community based organisations followed by private or government hospitals.

Conclusions

Overall, MSM in Malaysia reported a relatively low level of willingness to use PrEP, although willingness was higher among those previously aware of PrEP. There is a need to provide PrEP at affordable cost, increase demand and awareness of PrEP, and to provide access to this preventative medication via diverse, integrated and tailored sexual health services.

Cross-border injection drug use and HIV and hepatitis C virus seropositivity among people who inject drugs in San Diego, California

BACKGROUND

The prevalence of HIV and Hepatitis C Virus (HCV) are significantly lower among people who inject drugs (PWID) in San Diego, CA, USA compared with PWID in Tijuana, Mexico, located directly across the border. We investigated associations between cross-border injection drug use (IDU), HIV and HCV seroprevalence and engagement in injecting risk behaviours while on each side of the border.

METHODS

Using baseline interviews and serologic testing data from STAHR II, a longitudinal cohort study of PWID in San Diego, bivariate and multivariable logistic regression analyses examined associations between recent (past six months) cross-border IDU and HIV and HCV antibody seropositivity, socio-demographics, drug use characteristics, and participants' connections to, and perceptions about Mexico. Chi-squared tests and McNemar tests examined associations between cross-border IDU and injecting risk behaviours.

RESULTS

Of the 567 participants (93% U.S.-born, 73% male, median age 45 years), 86 (15%) reported recent cross-border IDU. Cross-border IDU was not associated with HIV (OR: 0.85, 95% CI: 0.37-1.95) or HCV seropositivity (OR: 1.01, 95% CI: 0.62-1.65). Age, identifying as Hispanic or Latino/a, and being concerned about risk of violence when travelling to Mexico were independently associated with decreased odds of recent cross-border IDU. Injecting cocaine at least weekly, having ever lived in Mexico and knowing PWID who reside in Mexico were associated with increased odds of recent cross-border IDU. PWID who reported cross-border IDU were significantly less likely to engage in receptive needle sharing, equipment sharing, and public injection while in Mexico compared with in San Diego (all p<0.001).

CONCLUSION

Prevalence of HIV and HCV infection was similar among PWID who had and had not injected in Mexico, possibly due to practising safer injecting while in Mexico. Research is needed to elucidate contextual factors enabling U.S. PWID to inject safely while in Mexico.

Examining the link between cocaine binging and individual, social and behavioral factors among street-based cocaine users

AIMS

To estimate the prevalence of cocaine binging and examine associated factors, to characterize binge episodes and to study the relationship between cocaine binging and HIV and HCV risk behaviors among street-based cocaine users.

METHODS

A prospective cohort study was conducted in Montréal, Canada. Interviewer-administered questionnaire were carried out at 3-month intervals. Cocaine binging was defined as using large quantities of cocaine, without stopping, over a limited period of time, until resources run out or until being physically incapable of consuming. Generalized Estimation Equations (GEE) analyses were used. Covariates considered included demographic, behavioral, mental health and social risk factors.

FINDINGS

In total, 605 participants were recruited. Prevalence of cocaine binging over the month prior to recruitment was 24.5%. Correlates of cocaine binging were older age (AOR 1.46), homelessness (AOR 1.44), criminal/marginal income strategies (AOR 1.61), high psychological distress (AOR 1.31), high cocaine dependence (AOR 3.71), drug overdoses (AOR 1.56) and smoking as the main route of cocaine administration (AOR 1.38). Additional GEE analyses showed that cocaine binging was significantly associated with the sharing of drug paraphernalia (AOR 1.35) and sexual relations under the influence of cocaine (AOR 1.21).

CONCLUSION

Cocaine binging is frequent among street-based cocaine users and is associated with markers of vulnerability. It is also associated with increased odds of both sexual and drug use risk behaviors. Interventions need to be tailored in order to help cocaine bingers develop personal strategies that could prevent binging. Harm reduction programs should help cocaine bingers adequately assess their drug equipment needs.

Heroin use is associated with lower levels of restriction factors and type I interferon expression and facilitates HIV-1 replication

Heroin use is associated with increased incidence of infectious diseases such as HIV-1 infection, as a result of immunosuppression to a certain extent. Host restriction factors are recently identified cellular proteins with potent antiviral activities. Whether heroin use impacts on the in vivo expression of restriction factors that result in facilitating HIV-1 replication is poorly understood. Here we recruited 432 intravenous drug users (IDUs) and 164 non-IDUs at high-risk behaviors. Based on serological tests, significantly higher prevalence of HIV-1 infection was observed among IDUs compared with non-IDUs. We included those IDUs and non-IDUs without HIV-1 infection, and found IDUs had significantly lower levels of TRIM5α, TRIM22, APOBEC3G, and IFN-α, -β expression than did non-IDUs. We also directly examined plasma viral load in HIV-1 mono-infected IDUs and non-IDUs and found HIV-1 mono-infected IDUs had significantly higher plasma viral load than did non-IDUs. Moreover, intrinsically positive correlation between type I interferon and TRIM5α or TRIM22 was observed, however, which was dysregulated following heroin use. Collectively, heroin use benefits HIV-1 replication that may be partly due to suppression of host restriction factors and type I interferon expression.

Overlapping substance using high-risk groups and infectious diseases: how dynamic modelling can evaluate risk and target HIV prevention

It’s difficult to develop infectious disease interventions (such as for HIV) for overlapping high-risk populations such as people who inject drugs, men who have sex with men, and female sex workers, where there are multiple transmission routes. Recent advances in dynamic modelling of coinfection epidemics could disentangle the contributions of different risk groups and behaviours to help develop more efficient and effective prevention interventions.

Impact of length of injecting career on HIV incidence among people who inject drugs

We examined the relationship between duration of injecting career and HIV seroconversion among people who inject drugs (PWID) in Vancouver, Canada. Data were derived from HIV-negative PWID enrolled in a prospective cohort study. We employed Kaplan-Meier methods and Cox regression to investigate the effect of length of time since injection drug use initiation on time to HIV seroconversion. In multivariable Cox analysis, duration of injecting career was negatively associated with time to HIV seroconversion (adjusted hazard ratio=0.82; 95% confidence interval [CI]: 0.69-0.97). Our findings highlight the need for interventions that target individuals who participate in high-risk drug use behaviors.