Increased Prevalence of Controlled Viremia and Decreased Rates of HIV Drug Resistance Among HIV-Positive People Who Use Illicit Drugs During a Community-wide Treatment-as-Prevention Initiative

Experiencing homelessness and progression through the HIV cascade of care among people who use drugs

OBJECTIVE

To investigate the longitudinal association between periods of homelessness and progression through the HIV cascade of care among people who use drugs (PWUD) with universal access to no-cost HIV treatment and care.

DESIGN

Prospective cohort study.

METHODS

Data were analysed from the ACCESS study, including systematic HIV clinical monitoring and a confidential linkage to comprehensive antiretroviral therapy (ART) dispensation records. We used cumulative link mixed-effects models to estimate the longitudinal relationship between periods of homelessness and progression though the HIV cascade of care.

RESULTS

Between 2005 and 2019, 947 people living with HIV were enrolled in the ACCESS study and 304 (32.1%) reported being homeless at baseline. Homelessness was negatively associated with overall progression through the HIV cascade of care [adjusted partial proportional odds ratio (APPO) = 0.56, 95% confidence interval (CI): 0.49-0.63]. Homelessness was significantly associated with lower odds of progressing to each subsequent stage of the HIV care cascade, with the exception of initial linkage to care.

CONCLUSIONS

Homelessness was associated with a 44% decrease in the odds of overall progression through the HIV cascade of care, and a 41-54% decrease in the odds of receiving ART, being adherent to ART and achieving viral load suppression. These findings support calls for the integration of services to address intersecting challenges of HIV, substance use and homelessness among marginalized populations such as PWUD.

Injecting drugs alone during an overdose crisis in Vancouver, Canada

BACKGROUND

Settings throughout Canada and the USA continue to experience crises of overdose death due to the toxic unregulated drug supply. Injecting drugs alone limits the potential for intervention and has accounted for a significant proportion of overdose deaths, yet the practice remains understudied. We sought to examine the practice of injecting alone among people who inject drugs (PWID) in Vancouver, Canada.

METHODS

Data were derived from two prospective cohorts of people who use drugs between June 2016 and November 2018. This analysis was restricted to participants who, in the previous 6 months, reported any injection drug use. Rates of injecting alone were categorized as always, usually, sometimes, or occasionally. We fit a multivariable generalized linear mixed model to identify factors associated with injecting drugs alone.

RESULTS

Among 1070 PWID who contributed 3307 observations, 931 (87%) reported injecting alone at least once during the study period. In total, there were 729 (22%) reports of always injecting alone, 722 (21.8%) usually, 471 (14.2%) sometimes, 513 (15.5%) occasionally, and 872 (26.4%) never. In a multivariable model, factors positively associated with injecting drugs alone included male sex (adjusted odds ratio [AOR] 1.69; 95% confidence interval [CI] 1.20-2.37), residence in the Downtown Eastside neighbourhood (AOR 1.43; 95% CI 1.08-1.91), binge drug use (AOR 1.36; 95% CI 1.08-1.72), and experiencing physical or sexual violence or both (AOR 1.43; 95% CI 1.00-2.03). Protective factors included Indigenous ancestry (AOR 0.71; 95% CI 0.52-0.98) and being in a relationship (AOR 0.30; 95% CI 0.23-0.39).

CONCLUSION

We observed that injecting alone, a key risk for overdose mortality, was common among PWID in Vancouver. Our findings underline the need for additional overdose prevention measures that are gender-specific, culturally appropriate, violence- and trauma-informed, and available to those who inject alone.

HIV and Incarceration: Implications for HIV-Positive People Who Use Illicit Drugs During a Seek, Test, Treat, and Retain Initiative in Canada

People who use illicit drugs (PWUD) face increased exposure to the criminal justice system and disproportionate burdens of HIV infection. This article investigated the effects of incarceration on HIV cascade of care-related measures in a setting with a community-wide seek, test, treat, and retain (STTR) initiative. Using a multivariable logistic regression analysis of 935 HIV-positive PWUD between 2005 and 2017, this article showed a negative relationship between periods of incarceration and two measures of engagement in clinical care for HIV among PWUD: recent dispensation of antiretroviral therapy and suppression of HIV viral load. These findings suggest the benefits of STTR-based efforts are limited by exposure to the criminal justice system and highlight the need for additional supports for PWUD with HIV exposed to the criminal justice system.

Assessing the Temporality Between Transitions onto Opioid Agonist Therapy and Engagement with Antiretroviral Therapy in a Cohort of HIV-Positive People Who Use Opioids Daily

A robust evidence-base describes the beneficial association between opioid agonist therapy (OAT) and HIV-related outcomes among people living with HIV and opioid use disorder. While some evidence suggests the stabilizing effect of OAT on antiretroviral therapy (ART) treatment engagement, less is understood about the potential for an inverse relationship. We sought to examine the relationship between transitions in ART engagement and transitions onto OAT. We used data from a prospective cohort of people living with HIV who use drugs in Vancouver, Canada-a setting with no-cost access to ART and low or no-cost access to OAT among low-income residents. Restricting the sample to those who reported daily or greater opioid use, we used generalized linear mixed-effects models to estimate the relationships between our primary outcome of transitions onto OAT (methadone or buprenorphine/naloxone) and transitions (1) onto ART and (2) into ART adherence. Subsequent analyses assessed the temporal sequencing of transitions. Between 2005 and 2017, among 433 participants, 48.3% reported transitioning onto OAT at least once. In concurrent analyses, transitions onto ART were positively and significantly associated with transitions onto OAT. Temporal sequencing revealed that transitions into OAT were also positively and significantly associated with subsequent transitions onto ART. OAT's potential to facilitate the uptake of ART points to the continued need to scale-up low-threshold, client-centered substance use services integrated alongside HIV care.

Periods of Homelessness Linked to Higher VACS Index Among HIV-Positive People Who Use Drugs

We sought to evaluate the impact of homelessness on HIV disease progression among people who use unregulated drugs (PWUD) living with HIV and test if this association was mediated by adherence to antiretroviral therapy (ART). We applied general linear mixed-effects modeling to estimate the longitudinal relationship between homelessness and the Veterans Aging Cohort Study (VACS) Index, a validated measure of HIV disease progression that predicts all-cause mortality, among a prospective cohort of PWUD. In a longitudinal model adjusted for ART adherence, homelessness was significantly associated with increased VACS Index scores and 16% of the association was mediated by ART adherence. These findings indicate that homelessness was a significant risk factor for HIV disease progression and this association was marginally mediated by ART adherence. Future studies are needed to quantify the other mechanisms (e.g., food insecurity, mental health) by which homelessness increases mortality risk among PWUD living with HIV.

Inability to access primary care clinics among people who inject drugs in a Canadian health care setting

OBJECTIVE

To examine the prevalence and correlation of self-reported inability to access community primary care clinics among people who inject drugs (PWID).

DESIGN

Self-report questionnaire data.

SETTING

Vancouver, BC.

PARTICIPANTS

Data were derived from 3 prospective cohort studies of PWID between 2013 and 2016.

MAIN OUTCOME MEASURES

Multivariable generalized estimating equations were used to determine prevalence of and reasons for self-reported inability to access primary care, as well as factors associated with inability to access care.

RESULTS

Of 1396 eligible participants, including 525 (37.6%) women, 209 (15.0%) persons were unable to access a primary care clinic at some point during the study period. In the multivariable analysis, factors independently associated with inability to access clinics included ever being diagnosed with a mental health disorder (adjusted odds ratio [AOR] = 1.63, 95% CI 1.14 to 2.35), dealing drugs (AOR = 1.60, 95% CI 1.15 to 2.22), using emergency services (AOR = 1.51, 95% CI 1.13 to 2.02), being female (AOR = 1.49, 95% CI 1.08 to 2.08), and testing positive for HIV (AOR = 0.47, 95% CI 0.30 to 0.72) (for all factors, P < .05).

CONCLUSION

Specific exposures were linked to challenges in accessing primary care among the sample of PWID, even in a publicly funded health care setting. Notably, models designed for care of people with HIV appear to increase access to primary care among PWID. Further research is needed to determine how to effectively treat accompanying mental illness, how to provide women-centred services, and how to connect people with primary care who would likely otherwise go to the emergency department.

Withdrawal-associated injury site pain prevalence and correlates among opioid-using people who inject drugs in Vancouver, Canada

BACKGROUND

Pain can return temporarily to old injury sites during opioid withdrawal. The prevalence and impact of opioid withdrawal-associated injury site pain (WISP) in various groups is unknown.

METHODS

Using data from observational cohorts, we estimated the prevalence and correlates of WISP among opioid-using people who inject drugs (PWID). Between June and December 2015, data on WISP and opioid use behaviours were elicited from participants in three ongoing prospective cohort studies in Vancouver, Canada, who were aged 18 years and older and who self-reported at least daily injection of heroin or non-medical presciption opioids.

RESULTS

Among 631 individuals, 276 (43.7 %) had a healed injury (usually pain-free), among whom 112 (40.6 %) experienced WISP, representing 17.7 % of opioid-using PWID interviewed. In a multivariable logistic regression model, WISP was positively associated with having a high school diploma or above (Adjusted Odds Ratio [AOR] = 2.23, 95 % Confidence Interval [CI]: 1.31-3.84), any heroin use in the last six months (AOR = 2.00, 95 % CI: 1.14-3.57), feeling daily pain that required medication (AOR = 2.06, CI: 1.18-3.63), and negatively associated with older age at first drug use (AOR = 0.96, 95 % CI: 0.93-0.99). Among 112 individuals with WISP, 79 (70.5 %) said that having this pain affected their opioid use behaviour, of whom 57 (72.2 %) used more opioids, 19 (24.1 %) avoided opioid withdrawal, while 3 (3.8 %) no longer used opioids to avoid WISP.

CONCLUSIONS

WISP is prevalent among PWID with a previous injury, and may alter opioid use patterns. Improved care strategies for WISP are warrented.

Sociodemographic, Ecological, and Spatiotemporal Factors Associated with Human Immunodeficiency Virus Drug Resistance in Florida: A Retrospective Analysis

BACKGROUND

Persons living with human immunodeficiency virus (HIV) with resistance to antiretroviral therapy are vulnerable to adverse HIV-related health outcomes and can contribute to transmission of HIV drug resistance (HIVDR) when nonvirally suppressed. The degree to which HIVDR contributes to disease burden in Florida-the US state with the highest HIV incidence- is unknown.

METHODS

We explored sociodemographic, ecological, and spatiotemporal associations of HIVDR. HIV-1 sequences (n = 34 447) collected during 2012-2017 were obtained from the Florida Department of Health. HIVDR was categorized by resistance class, including resistance to nucleoside reverse-transcriptase , nonnucleoside reverse-transcriptase , protease , and integrase inhibitors. Multidrug resistance and transmitted drug resistance were also evaluated. Multivariable fixed-effects logistic regression models were fitted to associate individual- and county-level sociodemographic and ecological health indicators with HIVDR.

RESULTS

The HIVDR prevalence was 19.2% (nucleoside reverse-transcriptase inhibitor resistance), 29.7% (nonnucleoside reverse-transcriptase inhibitor resistance), 6.6% (protease inhibitor resistance), 23.5% (transmitted drug resistance), 13.2% (multidrug resistance), and 8.2% (integrase strand transfer inhibitor resistance), with significant variation by Florida county. Individuals who were older, black, or acquired HIV through mother-to-child transmission had significantly higher odds of HIVDR. HIVDR was linked to counties with lower socioeconomic status, higher rates of unemployment, and poor mental health.

CONCLUSIONS

Our findings indicate that HIVDR prevalence is higher in Florida than aggregate North American estimates with significant geographic and socioecological heterogeneity.

Behavioural, social and structural-level risk factors for developing AIDS among HIV-positive people who use injection drugs in a Canadian setting, 1996-2017

People who use injection drugs (PWID) experience high rates of HIV acquisition and, as a result of lower rates of optimal access and adherence to combination antiretroviral therapy (ART), experience worse HIV treatment outcomes than other key affected populations. However, the incidence and risk factors for the development of AIDS among HIV-positive PWID have not been completely described. We used data from a community-recruited prospective cohort of HIV-positive PWID in Vancouver, Canada, a setting with universal no-cost ART and a comprehensive clinical monitoring registry. We used multivariable extended Cox models to identify factors associated with time to AIDS. Between 1996 and 2017, 396 participants, including 140 (35.4%) women, were followed for a median of 39.0 months (interquartile range: 16.6-76.2), among whom 165 (41.7%) developed AIDS. In a multivariable model, homelessness (Adjusted Hazard Ratio [AHR] = 1.76 (1.18-2.61)) and injection drug use within the preceding six months (AHR = 1.74 (1.17-2.58)) were independently associated with a higher risk of developing AIDS. Despite widespread scale-up of programmes to improve ART utilization, significant risk factors for the development of AIDS remain among HIV-positive PWID in this setting.

The effect of injecting alone on the use of drug checking services among people who inject drugs

OBJECTIVES

Drug checking services aim to provide people who use drugs with information on the content and purity of their substances as a harm reduction intervention. The objective of this study was to determine the relationship between injecting alone and use of drug checking services in Vancouver, Canada.

METHODS

Data were derived from three prospective cohort studies of people who inject drugs (PWID). We conducted bivariable and multivariable logistic regression analysis to estimate the effect of injecting alone on use of drug checking services.

RESULTS

Between May 2018 and December 2018, a total of 793 people who inject drugs were included in the study: 579 (73.0%) reported injecting alone and 177 (22.3%) reported use of drug checking services. In a multivariable model adjusted for various confounders (including various sociodemographic variables, drug use patterns, and whether participants had suffered physical attacks/violence), injecting alone was negatively associated with use of drug checking services (Adjusted Odds Ratio = 0.65; 95% Confidence Interval: 0.44-0.97).

CONCLUSIONS

We observed a negative association between injecting drugs alone and use of drug checking services, which may be due in part to a number of exogenous factors that prevent people who inject alone from accessing drug checking services (e.g., stigma, location of services). As these individuals are at heightened risk of experiencing overdoses, there is a need to pursue other strategies to reach this group of people who use drugs.

Moving into an urban drug scene among people who use drugs in Vancouver, Canada: Latent class growth analysis

Background

Urban drug scenes are characterized by high prevalence of illicit drug dealing and use, violence and poverty, much of which is driven by the criminalization of people who use illicit drugs (PWUD) and the associated stigma. Despite significant public health needs, little is understood about patterns of moving into urban drug scenes among PWUD. Therefore, we sought to identify trajectories of residential mobility (hereafter ‘mobility’) among PWUD into the Downtown Eastside (DTES), an urban neighbourhood with an open drug scene in Vancouver, Canada, as well as characterize distinct trajectory groups among PWUD.

Methods

Data were derived from three prospective cohort studies of community-recruited PWUD in Vancouver between 2005 and 2016. We used latent class growth analysis (LCGA) to identify distinct patterns of moving into the DTES among participants residing outside of DTES at baseline. Multivariable multinomial logistic regression was used to determine baseline factors associated with each trajectory group.

Results

In total, 906 eligible participants (30.9% females) provided 9,317 observations. The LCGA assigned four trajectories: consistently living outside of DTES (52.8%); early move into DTES (11.9%); gradual move into DTES (19.5%); and move in then out (15.8%). Younger PWUD, those of Indigenous ancestry, those who were homeless or living in a single-room occupancy hotel (SRO), and those injecting drugs daily were more likely to move in then out of DTES (all p<0.05). Living in an SRO, daily injection drug use, and recent incarceration were also positively associated with early mobility (all p<0.05).

Conclusions

Nearly half of the participants moved into the DTES. Younger PWUD and Indigenous peoples appeared to have particularly high mobility, as did those with markers of social-structural vulnerability and high intensity drug use. These findings indicate a need to tailor existing social and health services within the DTES and expand affordable housing options outside the DTES.

Predictors of Antiretroviral Adherence Self-efficacy Among People Living With HIV/AIDS in a Canadian Setting

BACKGROUND

Suboptimal adherence to antiretroviral therapy (ART) among people living with HIV/AIDS (PLWHA) who use illicit drugs remains an ongoing health concern. Although health outcomes associated with adherence self-efficacy have been well-documented, there is dearth research exploring the predictors of this construct. This study sought to identify possible determinants of adherence self-efficacy among a cohort of PLWHA who use illicit drugs.

METHODS

From December 2004 to May 2014, we collected data from the AIDS Care Cohort to evaluate Exposure to Survival Services, a prospective cohort of adult PLWHA who use illicit drugs in Vancouver, Canada. We used multivariate generalized estimating equation analyses to identify longitudinal factors independently associated with higher adherence self-efficacy.

RESULTS

Among 742 participants, 493 (66.4%) identified as male and 406 (54.7%) reported white ancestry. In multivariate generalized estimating equation analysis, older age at ART initiation (adjusted odds ratio [AOR] = 1.02, 95% confidence interval [CI]: 1.00 to 1.03) and recent year of baseline interview (AOR = 1.08, 95% CI: 1.05 to 1.11) were independently associated with higher adherence self-efficacy, whereas homelessness (AOR = 0.78, 95% CI: 0.65 to 0.94), ≥daily crack smoking (AOR = 0.81, 95% CI: 0.68 to 0.96), experienced violence (AOR = 0.82, 95% CI: 0.69 to 0.98), and childhood abuse (AOR = 0.75, 95% CI: 0.60 to 0.92) were negatively associated.

CONCLUSIONS

These findings highlight the potential role that personal and contextual factors can play in predicting levels of ART adherence self-efficacy. Future research should seek to identify and validate strategies to optimize adherence self-efficacy.

Criminal Justice System Involvement as a Risk Factor for Detectable Plasma HIV Viral Load in People Who Use Illicit Drugs: A Longitudinal Cohort Study

Among HIV-positive people who use illicit drugs (PWUD) in our setting, repeated periods of incarceration adversely affect ART adherence in a dose-dependent manner. However, the impact of non-custodial criminal justice involvement on HIV-related outcomes has not been previously investigated. Data were obtained from a longitudinal cohort of HIV-positive PWUD in a setting of universal no-cost ART and complete dispensation records. Multivariate generalized estimating equations were used to calculate the longitudinal odds of having a detectable HIV VL (VL) associated with custodial and non-custodial CJS exposure. Between 2005 and 2014, 716 HIV-positive ART-exposed PWUD were recruited. In multivariate analysis, both custodial [Adjusted odds ratio (AOR) 0.61, 95% CI 0.45-0.82] and noncustodial (AOR 0.78, 95% CI 0.62-0.99) involvement in the criminal justice system was associated with detectable HIV VL. Among HIV-positive PWUD, both custodial and non-custodial criminal justice involvement is associated with worse HIV treatment outcomes. Our findings highlight the need for increased ART adherence support across the full spectrum of the criminal justice system.

Engagement in Maximally-Assisted Therapy and Adherence to Antiretroviral Therapy Among a Cohort of Indigenous People Who Use Illicit Drugs

Throughout the world, Indigenous populations experience a disproportionate burden of HIV infection. Maximally-assisted therapy (MAT) is an interdisciplinary care intervention that includes ART dispensation to support individuals with a history of addiction and homelessness. This study sought to longitudinally evaluate the relationship between engagement in MAT and achieving optimal adherence using data from an ongoing cohort of HIV-positive individuals who use drugs in Vancouver, Canada, where HIV/AIDS treatment is offered at no cost. Between December 2005 and November 2016, 354 HIV-positive Indigenous participants were enrolled and data were analyzed using generalized mixed-effects (GLMM) and marginal structural modeling. In both multivariable analyses, engagement in MAT was independently associated with optimal adherence to ART (GLMM: AOR = 4.92, 95% CI 3.18-7.62; marginal structural model: AOR = 5.76, 95% CI 3.34-9.96). MAT-based programmes could be a part of a renewed evidence-base to elevated levels of preventable HIV/AIDS-associated morbidity, mortality and viral transmission among Indigenous peoples in Canada.

Prevalence and Correlates of Reporting Difficulty Taking Antiretroviral Treatment Among HIV-Positive Illicit Drug Users in Vancouver, Canada: A Longitudinal Analysis

People living with HIV who use illicit drugs continue to experience high rates of suboptimal treatment outcomes from antiretroviral therapy (ART). Although previous studies have identified important behavioural, social and structural barriers to ART adherence, the effects of patient-level factors have not been fully evaluated. Thus, we sought to investigate the prevalence and correlates of reporting ART was difficult to take among a cohort of illicit drug users in Vancouver, Canada. We accessed data from the AIDS Care Cohort to evaluate Exposure to Survival Services (ACCESS), an ongoing prospective cohort of HIV-positive illicit drug users linked to comprehensive HIV clinical monitoring records. We used generalized linear mixed-effects modeling to identify factors longitudinally associated with periods in which individuals reported they found ART difficult to take. Between December 2005 and May 2014, 746 ART-exposed illicit drug users were recruited and contributed at least one study interview. Finding ART hard to take was reported by 209 (28.0%) participants at baseline, and 460 (61.7%) participants throughout the study period. Patients ingesting a greater daily pill count (adjusted odds ratio [AOR] = 1.12 per pill, 95% confidence interval [CI] 1.08-1.17) and experiencing barriers to healthcare (AOR = 1.64, 95% CI 1.34-2.01) were more likely to report difficulty taking ART. Patients less likely to report satisfaction with their HIV physician (AOR = 0.76, 95% CI 0.58-1.00) and achieve a non-detectable HIV viral load (AOR = 0.62, 95% CI 0.51-0.74) were more likely to report finding ART hard to take. In this community-recruited cohort of ART-exposed illicit drug users, a substantial proportion reported they found HIV treatment hard to take, which was clearly linked to higher dissatisfaction with healthcare experiences and, most importantly, a lower likelihood of experiencing optimal virologic outcomes. Our findings reveal a number of opportunities to improve HIV treatment experiences and outcomes for people who use illicit drugs, including the use of treatment regimens with lower pill burdens, as well as reducing barriers to healthcare access.

High-intensity cannabis use is associated with retention in opioid agonist treatment: a longitudinal analysis

BACKGROUND AND AIMS

Cannabis use is common among people on opioid agonist treatment (OAT), causing concern for some care providers. However, there is limited and conflicting evidence on the impact of cannabis use on OAT outcomes. Given the critical role of retention in OAT in reducing opioid-related morbidity and mortality, we aimed to estimate the association of at least daily cannabis use on the likelihood of retention in treatment among people initiating OAT. As a secondary aim we tested the impacts of less frequent cannabis use.

DESIGN

Data were drawn from two community-recruited prospective cohorts of people who use illicit drugs (PWUD). Participants were followed for a median of 81 months (interquartile range = 37-130).

SETTING

Vancouver, Canada.

PARTICIPANTS

This study comprised a total of 820 PWUD (57.8% men, 59.4% of Caucasian ethnicity, 32.2% HIV-positive) initiating OAT between December 1996 and May 2016. The proportion of women was higher among HIV-negative participants, with no other significant differences.

MEASUREMENTS

The primary outcome was retention in OAT, defined as remaining in OAT (methadone or buprenorphine/naloxone-based) for two consecutive 6-month follow-up periods. The primary explanatory variable was cannabis use (at least daily versus less than daily) during the same 6-month period. Confounders assessed included: socio-demographic characteristics, substance use patterns and social-structural exposures.

FINDINGS

In adjusted analysis, at least daily cannabis use was positively associated with retention in OAT [adjusted odds ratio (aOR) = 1.21, 95% confidence interval (CI) = 1.04-1.41]. Our secondary analysis showed that compared with non-cannabis users, at least daily users had increased odds of retention in OAT (aOR = 1.20, 95% CI = 1.02-1.43), but not less than daily users (aOR = 1.00, 95% CI = 0.87-1.14).

CONCLUSIONS

Among people who use illicit drugs initiating opioid agonist treatment in Vancouver, at least daily cannabis use was associated with approximately 21% greater odds of retention in treatment compared with less than daily consumption.

Substance Use and Adherence to Antiretroviral Therapy: What Is Known and What Is Unknown

PURPOSE OF REVIEW

People who use drugs face multiple challenges to achieve optimal HIV treatment outcomes. This review discusses the current knowledge in substance use and antiretroviral therapy adherence, highlighting recent findings and potential interventions.

RECENT FINDINGS

Studies continue to demonstrate the negative impacts of substance use and related disorders on antiretroviral therapy adherence, with the exception of cannabis. Evidence-based addiction treatment, in particular, opioid agonist therapy, appears to improve adherence levels. Most individual-level adherence specific interventions did not provide sustained effects, and no studies evaluating structural-level interventions were found. Findings suggest the urgent need to scale-up opioid agonist therapy, as well as to simultaneously address multiple structural barriers to care to optimize HIV treatment outcomes among people who use drugs.

Patterns of Transmitted Drug Resistance and Virological Response to First-line Antiretroviral Treatment Among Human Immunodeficiency Virus-Infected People Who Use Illicit Drugs in a Canadian Setting

Background

Transmitted drug resistance (TDR) may compromise response to antiretroviral therapy (ART). However, there are limited data on TDR patterns and impacts among people who use illicit drugs (PWUD).

Methods

Data were drawn from 2 prospective cohorts of PWUD in Vancouver, Canada. We characterized patterns of TDR among human immunodeficiency virus (HIV)-infected PWUD, and assessed its impacts on first-line ART virological outcomes.

Results

Between 1996 and 2015, among 573 ART-naive PWUD (18% with recent HIV infection), the overall TDR prevalence was 9.8% (95% confidence interval [CI], 7.3%-12.2%), with an increasing trend over time, from 8.5% in 1996-1999 to 21.1% in 2010-2015 (P = .003), mainly driven by resistance to nonnucleoside reverse transcriptase inhibitors (NNRTIs). TDR-associated mutations were more common for NNRTIs (5.4%), followed by nucleoside reverse transcriptase inhibitors (3.0%) and protease inhibitors (1.9%). TDR prevalence was lower among recently infected PWUD (adjusted odds ratio, 0.39 [95% CI, .15-.87]). Participants with TDR had higher risk of virological failure than those without TDR (log-rank P = .037) in the first year of ART.

Conclusions

Between 1996 and 2015, TDR prevalence increased significantly among PWUD in Vancouver. Higher risk of virological failure among PWUD with TDR may be explained by some inappropriate ART prescribing, as well as undetected minority resistant variants in participants with chronic HIV infection. Our findings support baseline resistance testing early in the course of HIV infection to guide ART selection among PWUD in our setting.

Social and structural factors associated with greater time with a plasma HIV-1 RNA viral load above log10(1500) copies/ml among illicit drug users

OBJECTIVES

Although previous cross-sectional studies have identified correlates of detectable plasma HIV-1 RNA viral load (VL) among HIV-positive people who use drugs (PWUD), longitudinal factors associated with heightened HIV transmission potential have not been well described. Therefore, we longitudinally examined factors associated with amount of person-time spent above log10(1500) copies/ml plasma among HIV-positive PWUD in Vancouver, Canada.

DESIGN

Data were derived from a long-running prospective cohort of HIV-positive PWUD linked to comprehensive clinical records including systematic VL monitoring.

METHODS

We used generalized estimating equations modeling to longitudinally examine factors associated with person-time (in days) with a VL more than log10(1500) copies/ml plasma in the previous 180 days.

RESULTS

Between December 2005 and May 2014, 845 PWUD were eligible and included in the study. Participants spent an average of 26.8% of observation time with a VL more than log10(1500) copies/ml. In multivariable analyses, homelessness (Adjusted Rate Ratio [ARR] = 1.45) and lack of social support (ARR = 1.27) were positively associated with person-time with a VL more than log10(1500) copies/ml. Older age (ARR = 0.97) and enrolment in addiction treatment (ARR = 0.75) were negatively associated with the outcome in multivariable analyses (all P < 0.05).

CONCLUSION

Social and structural factors, including periods of homelessness or lacking in social support, were independently associated with greater amount of time with heightened HIV transmission potential. These findings suggest the need for targeted efforts to address modifiable contextual factors that contribute to increased risk of onward HIV transmission among PWUD.

HIV treatment as prevention among people who inject drugs - a re-evaluation of the evidence

Background

Population-level associations between community measures of HIV viral load and HIV incidence have been interpreted as evidence for HIV anti-retroviral treatment (ART) as prevention among people who inject drugs (PWID). However, investigation of concurrent HCV and HIV incidence trends allows examination of alternative explanations for the fall in HIV incidence. We estimate the contribution of ART and reductions in injecting risk for reducing HIV incidence in Vancouver between 1996 and 2007.

Methods

A deterministic model of HIV and HCV transmission among PWID was calibrated to the baseline (1996) HIV and HCV epidemic among PWID in Vancouver. While incorporating parameter uncertainty, the model projected what levels of ART protection and decreases in injecting risk could reproduce the observed reduction in HIV and HCV incidence for 1996-2007, and so what impact would have been achieved with just ART or just reductions in injecting risk.

Results

Model predictions suggest the estimated reduction (84%) in HCV incidence for 1996-2007 required a 59% (2.5-97.5 percentile range 49-76%) reduction in injecting risk, which accounted for nine-tenths of the observed decrease in HIV incidence; the remainder was achieved with a moderate ART efficacy for reducing sexual HIV infectivity (70%, 51-89%) and an uncertain ART efficacy for reducing injection-related HIV infectivity (44%, 0-96%). Despite this uncertainty, projections suggest that the decrease in injecting risk reduced HIV incidence by 76% (63-85%) and ART further reduced HIV incidence by 8% (2-19%), or on its own by 3% (-34-37%).

Conclusions

Observed declines in HIV incidence in Vancouver between 1996 and 2007 should be seen as a success for intensive harm reduction, whereas ART probably played a small role.

The impact of methadone maintenance therapy on access to regular physician care regarding hepatitis C among people who inject drugs

Background & aims

People who inject drugs (PWID) living with hepatitis C virus (HCV) infection often experience barriers to accessing HCV treatment and care. New, safer and more effective direct-acting antiviral-based therapies offer an opportunity to scale-up HCV-related services. Methadone maintenance therapy (MMT) programs have been shown to be effective in linking PWID to health and support services, largely in the context of HIV. The objective of the study was to examine the relationship between being enrolled in MMT and having access to regular physician care regarding HCV among HCV antibody-positive PWID in Vancouver, Canada.

Design

Three prospective cohort studies of people who use illicit drugs.

Setting

Vancouver, Canada.

Participants

We restricted the study sample to 1627 HCV-positive PWID between September 2005 and May 2015.

Measurements

A marginal structural model using inverse probability of treatment weights was used to estimate the longitudinal relationship between being enrolled in MMT and having a regular HCV physician and/or specialist.

Findings

In total, 1357 (83.4%) reported having access to regular physician care regarding HCV at least once during the study period. A marginal structural model estimated a 2.12 (95% confidence interval [CI]: 1.77–2.20) greater odds of having a regular HCV physician among participants enrolled in MMT compared to those not enrolled.

Conclusions

HCV-positive PWID who enrolled in MMT were more likely to report access to regular physician care regarding HCV compared to those not enrolled in MMT. These findings demonstrate that opioid agonist treatment may be helpful in linking PWID to HCV care, and highlight the need to better engage people who use drugs in substance use care, when appropriate.

Where is the greatest impact of uncontrolled HIV infection on AIDS and non-AIDS events in HIV?

OBJECTIVE

The extent to which controlled and uncontrolled HIV interact with ageing, European region of care and calendar year of follow-up is largely unknown.

METHOD

EuroSIDA participants were followed after 1 January 2001 and grouped according to current HIV progression risk; high risk (CD4 cell count ≤350/μl, viral load ≥10 000 copies/ml), low risk (CD4 cell count ≥500 cells/μl, viral load <50 copies/ml) and intermediate (other combinations). Poisson regression investigated interactions between HIV progression risk, age, European region of care and year of follow-up and incidence of AIDS or non-AIDS events.

RESULTS

A total of 16 839 persons were included with 136 688 person-years of follow-up. In persons aged 30 years or less, those at high risk had a six-fold increased incidence of non-AIDS compared with those at low risk, compared with a two-to-three-fold increase in older persons (P = 0.0004, interaction). In Eastern Europe, those at highest risk of non-AIDS had a 12-fold increased incidence compared with a two-to-four-fold difference in all other regions (P = 0.0029, interaction). Those at high risk of non-AIDS during 2001-2004 had a two-fold increased incidence compared with those at low risk, increasing to a five-fold increase between 2013 and 2016 (P < 0.0001, interaction). Differences among high, intermediate and low risk of AIDS were similar across age groups, year of follow-up and Europe (P = 0.57, 0.060 and 0.090, respectively, interaction).

CONCLUSION

Factors other than optimal control of HIV become increasingly important with ageing for predicting non-AIDS, whereas differences across Europe reflect differences in patient management as well as underlying socioeconomic circumstances. The differences between those at high, intermediate and low risk of non-AIDS between 2013 and 2016 likely reflects better quality of care.

Exposure to Rats and Rat-Associated Leptospira and Bartonella Species Among People Who Use Drugs in an Impoverished, Inner-City Neighborhood of Vancouver, Canada

Rat infestations are common, particularly in impoverished, inner-city neighborhoods. However, there has been little research into the nature and consequences of rat exposure in these neighborhoods, particularly in Canada. In this study, we sought to characterize exposure to rats and rat-associated Leptospira interrogans and Bartonella tribocorum, as well as risk factors associated with exposure, in residents (n = 202) of the Downtown Eastside (DTES) neighborhood of Vancouver, Canada. There was no evidence of exposure to rat-associated L. interrogans but 6/202 (3.0%) of participants were exposed to B. tribocorum, which is known to be circulating among DTES rats. We also found that frequent and close rat exposure was common among DTES residents, and that this exposure was particularly associated with injection drug use and outdoor income-generating activities (e.g., drug dealing). These risk factors may be good targets for interventions geared toward effectively reducing rat exposure.

Association between public injecting and drug-related harm among HIV-positive people who use injection drugs in a Canadian setting: A longitudinal analysis

BACKGROUND

and Aims Injecting illicit drugs in public settings has been linked to a higher risk of a range of drug-related harms, including overdose and HIV infection. However, the factors associated with public injecting among HIV-positive individuals have not been previously explored. We investigated the links between public drug injecting, drug-related harm, and HIV treatment measures among a cohort of HIV-positive persons who inject drugs (PWID) in a Canadian setting.

METHODS

We used data from a prospective cohort of HIV-positive PWID recruited from community settings in Vancouver, Canada, linked to comprehensive clinical monitoring data in the context of an ongoing Treatment-as-Prevention (TasP) initiative to examine harms associated with public injecting. We used generalized linear mixed-effects analyses to identify longitudinal factors associated with self-reported public drug injection.

RESULTS

Between 2005 and 2014, 626 HIV-seropositive PWID were recruited, of whom 213 (34%) reported public injection in the preceding 180days. In a longitudinal multivariable model, public injection was positively associated with daily heroin injection (Adjusted Odds Ratio [AOR]=2.63), incarceration (AOR=1.78), and detectable plasma HIV-1 RNA viral load (VL, AOR=1.42).

CONCLUSIONS

Public injecting was linked to numerous drug-related harms among HIV-seropositive PWID in this setting. Given its link with detectable VL, an important marker of poor HIV treatment outcomes, our findings support prioritizing individuals engaged in public injecting with harm reduction strategies as well as clinical and social supports as a part of TasP-based efforts to prevent HIV-related morbidity and mortality, and HIV transmission.

HIV, Tat and dopamine transmission

Human Immunodeficiency Virus (HIV) is a progressive infection that targets the immune system, affecting more than 37 million people around the world. While combinatorial antiretroviral therapy (cART) has lowered mortality rates and improved quality of life in infected individuals, the prevalence of HIV associated neurocognitive disorders is increasing and HIV associated cognitive decline remains prevalent. Recent research has suggested that HIV accessory proteins may be involved in this decline, and several studies have indicated that the HIV protein transactivator of transcription (Tat) can disrupt normal neuronal and glial function. Specifically, data indicate that Tat may directly impact dopaminergic neurotransmission, by modulating the function of the dopamine transporter and specifically damaging dopamine-rich regions of the CNS. HIV infection of the CNS has long been associated with dopaminergic dysfunction, but the mechanisms remain undefined. The specific effect(s) of Tat on dopaminergic neurotransmission may be, at least partially, a mechanism by which HIV infection directly or indirectly induces dopaminergic dysfunction. Therefore, precisely defining the specific effects of Tat on the dopaminergic system will help to elucidate the mechanisms by which HIV infection of the CNS induces neuropsychiatric, neurocognitive and neurological disorders that involve dopaminergic neurotransmission. Further, this will provide a discussion of the experiments needed to further these investigations, and may help to identify or develop new therapeutic approaches for the prevention or treatment of these disorders in HIV-infected individuals.

Continuing Links Between Substance Use and HIV Highlight the Importance of Nursing Roles

Links between HIV and substance use were identified early in the U.S. HIV epidemic. People who use drugs are at risk of HIV infection through shared injection equipment and risky sexual behaviors. In addition, substance use has negative health consequences for people living with HIV. The prescription opioid misuse epidemic, linked to injection drug use, hepatitis C infection, and HIV, poses a new threat to declining HIV rates. We reviewed evidence-based interventions that decrease HIV risk in people who use drugs (needle/syringe programs, medication-assisted treatment, engagement in HIV care, and preexposure prophylaxis/postexposure prophylaxis). The critical roles of nurses in HIV prevention/care for this population are described, including applying the principles of harm reduction, screening for substance use, and undertaking implementation and research efforts. As the nation's largest health care profession, nurses are positioned to contribute to the quality of HIV-related prevention/care for people who use drugs and to lead practice initiatives.

HIV and hepatitis C treatment uptake among people who use drugs participating in the Amsterdam Cohort Studies, 1985-2015

BACKGROUND

HIV-positive people who use drugs (PWUD) start antiretroviral therapy (ART) later than other risk groups, and among HCV-positive PWUD, HCV treatment uptake is low. Nowadays, HCV direct-acting antivirals (DAAs) are available and reimbursed in the Netherlands (since 2014). The Amsterdam Cohort Studies (ACS), initiated in 1985, provides us the opportunity to describe temporal trends in ART and HCV-treatment uptake among PWUD through 2015.

METHODS

We analyzed data from PWUD participating in the ACS between 1985 and 2015. ART and HCV-treatment data were obtained from ACS questionnaires and medical records. Treatment uptake was defined by: treatment initiation (the proportion initiating any kind of ART/HCV treatment when treatment-naïve) and coverage (the proportion ever treated for HIV/HCV) among all HIV-/HCV-RNA-positive PWUD. Each was calculated per calendar year. We estimated the cumulative probability of ART uptake in the pre-cART (<1996) and cART era (January 1, 1996) among HIV seroconverters, with all-cause mortality as a competing risk.

RESULTS

Of 1305 PWUD, 263 (20.2%) were HIV-antibody positive and 810 (62.1%) were HCV-antibody positive, at study entry. ART coverage increased over time, from 5.7% in 1990 and 42.2% in 1996 to 91.7% in 2015. The proportion initiating ART ranged from 4.8% in 1990 to 33.3% in 2011. At 8 years after HIV seroconversion, cumulative probability of ART uptake was 42.5% in the pre-cART era and 61.5% in the cART era. HCV treatment initiation peaked in 2006 (9.7%). HCV-treatment coverage was 43.9% in 2015 but lower among HIV-coinfected (23.5%) than HCV-monoinfected PWUD (52.5%). In 2015, 3.0% initiated HCV treatment with DAAs.

CONCLUSION

We observed an increase in ART and HCV-treatment coverage among PWUD over time. As expected, ART uptake was higher in the cART era than the pre-cART era. Although in 2015 HCV treatment coverage was relatively high, DAA uptake was still low.

High-intensity cannabis use and HIV clinical outcomes among HIV-positive people who use illicit drugs in Vancouver, Canada

BACKGROUND

Reforms to the legal status of medical and non-medical cannabis are underway in many jurisdictions, including Canada, as are renewed efforts to scale-up HIV treatment-as-prevention (TasP) initiatives. It has been suggested that high-intensity cannabis use may be associated with sub-optimal HIV treatment outcomes. Thus, using data from a setting with a community-wide treatment-as-prevention (TasP) initiative coinciding with increasing access to medical cannabis, we sought to investigate the possible impact of high-intensity cannabis use on HIV clinical outcomes.

METHODS

Data was derived from the ACCESS study, a prospective cohort of HIV-positive people who use illicit drugs (PWUD) in Vancouver, Canada. Cohort data was confidentially linked to comprehensive clinical profiles, including records of all antiretroviral therapy (ART) dispensations and longitudinal plasma HIV-1 RNA viral load (VL) monitoring. We used generalized estimating equations (GEEs) to estimate the longitudinal bivariable and multivariable relationships between at least daily cannabis use and two key clinical outcomes: overall engagement in ART care, and achieving a non-detectable VL among ART-exposed participants.

RESULTS

Between December 2005 and June 2015, 874 HIV-positive PWUD (304 [35%] non-male) were included in this study. In total, 788 (90%) were engaged in HIV care at least once over the study period, of whom 670 (85%) achieved non-detectable VL at least once. In multivariable analyses, ≥ daily cannabis use did not predict lower odds of ART care (Adjusted Odds Ratio [AOR]: 1.02, 95% confidence interval [CI]: 0.77-1.36) or VL non-detectability among ART-exposed (AOR: 0.96, 95% CI: 0.75-1.21). Upon testing for potential interactions, ≥ daily cannabis use was found to be negatively associated with ART engagement during periods of binge alcohol use (p<0.05).

CONCLUSION

With the exception of frequent cannabis use during periods of binge alcohol use, our results showed no statistically significant impact of daily cannabis use on the likelihood of ART care or VL non-detectability among ART-exposed HIV-positive PWUD. These findings are reassuring in light of the impending legalization of cannabis in Canada and ongoing efforts to expand TasP initiatives.

Mortality and virological failure among HIV-infected people who inject drugs on antiretroviral treatment in China: An observational cohort study

OBJECTIVE

HIV-infected people who inject drugs (PWID) have a disproportionally low rate of access to antiretroviral therapy (ART). We aimed to assess the impact of ART on 12-month mortality and virological failure of HIV-infected PWID in China, stratified by methadone maintenance treatment (MMT) and active drug use status.

METHODS

HIV-infected PWID who initiated ART at 29 clinics in 2011 were enrolled and followed in this prospective cohort study. Kaplan-Meier curves and log-rank tests were used to compare the survival probability. Risk factors for mortality and virological failure were evaluated by Cox proportional hazards models and logistic regression analyses.

RESULTS

A total of 1,633 participants initiated ART. At the time of initiation, 324 were on MMT, 625 were engaged in active drug use, and 684 had discontinued drug use but were not on MMT. At the 12-month follow-up, 80.3% remained on ART, 13.5% had discontinued ART, and 6.2% had died. Among the MMT group, active drug use group, and drug abstinent group, we observed all-cause mortality of 4.9%, 12.0%, and 1.5% and virological suppression of 51.9%, 41.1%, and 68.7%, respectively. Factors associated with both mortality and virological failure were drug use status, unemployment, and treatment facility type.

CONCLUSION

For HIV-infected PWID receiving ART, engagement in MMT and discontinuation of drug use were more likely to be associated with lower mortality and virological failure compared with active drug use. In order to maximize the clinical impact of ART, HIV treatment programs in China should be further integrated with MMT and social services.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

DISCUSSION

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

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

OBJECTIVE

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

METHODS

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

RESULTS

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

DISCUSSION/CONCLUSIONS

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

HIV infection among persons who inject drugs: ending old epidemics and addressing new outbreaks

AIDS among persons who inject drugs, first identified in December 1981, has become a global epidemic. Injecting drug use has been reported in 148 countries and HIV infection has been seen among persons who inject drugs in 61 countries. Many locations have experienced outbreaks of HIV infection among persons who inject drugs, under specific conditions that promote very rapid spread of the virus. In response to these HIV outbreaks, specific interventions for persons who inject drugs include needle/syringe exchange programs, medicated-assisted treatment (with methadone or buprenorphine) and antiretroviral therapy. Through a 'combined prevention' approach, these interventions significantly reduced new HIV infections among persons who inject drugs in several locations including New York City, Vancouver and France. The efforts effectively ended the HIV epidemic among persons who inject drugs in those locations. This review examines possible processes through which combined prevention programs may lead to ending HIV epidemics. However, notable outbreaks of HIV among persons who inject drugs have recently occurred in several countries, including in Athens, Greece; Tel-Aviv, Israel; Dublin, Ireland; as well as in Scott County, Indiana, USA. This review also considers different factors that may have led to these outbreaks. We conclude with addressing the remaining challenges for reducing HIV infection among persons who inject drugs.