Injection of cocaine is associated with a recent HIV outbreak in people who inject drugs in Luxembourg

Molecular epidemiology of HIV among people who inject drugs after the HIV-outbreak in Athens, Greece: Evidence for a 'slow burn' outbreak

BACKGROUND

New diagnoses of HIV-1 infection among people who inject drugs (PWID) in Athens, Greece, saw a significant increase in 2011 and a subsequent decline after 2013. Despite this, ongoing HIV-1 transmission persisted from 2014 to 2020 within this population. Our objective was to estimate the time of infection for PWID in Athens following the HIV-1 outbreak, explore the patterns of HIV-1 dispersal over time, and determine the duration from infection to diagnosis.

METHODS

Time from HIV-1 infection to diagnosis was estimated for 844 individuals infected within 4 PWID-specific clusters and for 8 PWID infected with sub-subtype A6 diagnosed during 2010-2019. Phylogeny reconstruction was performed using the maximum-likelihood method. HIV-1 infection dates were based on molecular clock calculations.

RESULTS

In total 86 of 92 (93.5%) sequences from PWID diagnosed during 2016-2019 were either related to the previously identified PWID-specific clusters (n = 81) or belonged to a new A6 cluster (n = 5). The median time between infection and diagnosis was 0.42 years during the outbreak period and 0.70 years during 2016-2019 (p < 0.001). The proportion of clustered sequences from PWID was very low at 5.3% during the pre-outbreak period (1998-2009), saw an increase to 41.7% one year before the outbreak in 2010, and consistently remained high during the whole period after 2011, spanning the post-outbreak period (2016-2019) with a range from 92.9% to 100%.

CONCLUSIONS

The substantial proportion of clustered infections (93.5%) during 2016-2019 implies a persistent 'slow burn' HIV outbreak among PWID in Athens, suggesting that the outbreak was not successfully eliminated. The consistently high proportion of clustered sequences since the onset of the outbreak suggests the persistence of ongoing HIV-1 transmission attributed to injection practices. Our findings underscore the importance of targeted interventions among PWID, considering the ongoing transmission rate and prolonged time from infection to diagnosis.

Gender identity, stimulant drug use, and criminal justice history on internalized stigma among a nationally representative sample of adults who misuse opioids

PURPOSE

The rise of fatal stimulant use among adults who use opioids is a public health problem. Internalized stigma is a barrier to substance use treatment, which is greater for women and populations with criminal justice involvement.

METHODS

Using a nationally representative sample of adults in the United States from a probability-based survey on household opinions in 2021, we examined characteristics of women (n = 289) and men (n = 416) who misuse opioids. In gender-stratified multivariable linear regression, we investigated factors associated with internalized stigma, and tested for the interaction of stimulant use and criminal justice involvement.

RESULTS

Compared to men, women reported greater mental health symptom severity (3.2 vs. 2.7 on a 1 to 6 scale, p < 0.001). Internalized stigma was similar between women (2.3 ± 1.1) and men (2.2 ± 0.1). Among women and not men, however, stimulant use was positively associated with internalized stigma (0.36, 95% CI [0.07, 0.65]; p = 0.02). Interaction between stimulant use and criminal justice involvement was negatively associated with internalized stigma among women (- 0.60, 95% CI [- 1.16, -0.04]; p = 0.04); among men, the interaction was not significant. Predictive margins illustrate among women, stimulant use eliminated the gap in internalized stigma such that women with no criminal justice involvement had a similar level of internalized stigma as women with criminal justice involvement.

CONCLUSION

Internalized stigma between women and men who misuse opioids differed based on stimulant use and criminal justice involvement. Future research should assess whether internalized stigma influences treatment utilization among women with criminal justice involvement.

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.

Incarceration history is associated with HIV infection among community-recruited people who inject drugs in Europe: A propensity-score matched analysis of cross-sectional studies

AIMS

We measured the association between a history of incarceration and HIV positivity among people who inject drugs (PWID) across Europe.

DESIGN, SETTING AND PARTICIPANTS

This was a cross-sectional, multi-site, multi-year propensity-score matched analysis conducted in Europe. Participants comprised community-recruited PWID who reported a recent injection (within the last 12 months).

MEASUREMENTS

Data on incarceration history, demographics, substance use, sexual behavior and harm reduction service use originated from cross-sectional studies among PWID in Europe. Our primary outcome was HIV status. Generalized linear mixed models and propensity-score matching were used to compare HIV status between ever- and never-incarcerated PWID.

FINDINGS

Among 43 807 PWID from 82 studies surveyed (in 22 sites and 13 countries), 58.7% reported having ever been in prison and 7.16% (n = 3099) tested HIV-positive. Incarceration was associated with 30% higher odds of HIV infection [adjusted odds ratio (aOR) = 1.32, 95% confidence interval (CI) = 1.09-1.59]; the association between a history of incarceration and HIV infection was strongest among PWID, with the lowest estimated propensity-score for having a history of incarceration (aOR = 1.78, 95% CI = 1.47-2.16). Additionally, mainly injecting cocaine and/or opioids (aOR = 2.16, 95% CI = 1.33-3.53), increased duration of injecting drugs (per 8 years aOR = 1.31, 95% CI = 1.16-1.48), ever sharing needles/syringes (aOR = 1.91, 95% CI = 1.59-2.28) and increased income inequality among the general population (measured by the Gini index, aOR = 1.34, 95% CI = 1.18-1.51) were associated with a higher odds of HIV infection. Older age (per 8 years aOR = 0.84, 95% CI = 0.76-0.94), male sex (aOR = 0.77, 95% CI = 0.65-0.91) and reporting pharmacies as the main source of clean syringes (aOR = 0.72, 95% CI = 0.59-0.88) were associated with lower odds of HIV positivity.

CONCLUSIONS

A history of incarceration appears to be independently associated with HIV infection among people who inject drugs (PWID) in Europe, with a stronger effect among PWID with lower probability of incarceration.

A new outbreak of HIV infection among people who inject drugs during the COVID-19 pandemic in Greece

BACKGROUND

Multiple HIV outbreaks have been recorded among people who inject drugs (PWID) since 2010. During an intervention for PWID in 2019-2021 in Thessaloniki, Greece, an increasing number of HIV cases was documented. Here, we provide an analysis of this new outbreak.

METHODS

ALEXANDROS was a community-based program and participation included interviewing, rapid HIV/HCV tests, counselling and linkage to care. PWID were recruited through Respondent-Driven Sampling (RDS) in five sampling rounds. Crude and RDS-weighted HIV prevalence estimates were obtained. HIV incidence was estimated from data on 380 initially seronegative PWID with at least two tests. Multivariable Cox proportional hazards model was used to assess risk factors for HIV seroconversion.

RESULTS

In total, 1,101 PWID were recruited. At first participation, 53.7% were current PWID, 20.1% homeless, 20.3% on opioid substitution treatment and 4.8% had received syringes in the past 12 months. HIV prevalence (95% CI) was 7.0% (5.6-8.7%) and an increasing trend was observed over 2019-2021 (p = 0.002). Two-thirds of the cases (67.5%) were new diagnoses. HIV incidence was 7.0 new infections/100 person-years (95% CI:4.8-10.2). Homelessness in the past 12 months (HR:2.68; 95% CI:1.24-5.81) and receptive syringe sharing (HR:3.86; 95% CI:1.75-8.51) were independently associated with increased risk of seroconversion. By the end of the program, 67.3% of the newly diagnosed cases initiated antiretroviral treatment.

CONCLUSIONS

A new HIV outbreak among PWID was documented in Greece during the COVID-19 pandemic with homelessness and syringe sharing being associated with increased risk of HIV acquisition. Peer-driven programs targeting the population of high-risk underserved PWID can be used to early identify emerging outbreaks and to improve linkage to HIV care.

Impact of COVID-19 & Response Measures on HIV-HCV Prevention Services and Social Determinants in People Who Inject Drugs in 13 Sites with Recent HIV Outbreaks in Europe, North America and Israel

HIV/HCV prevention among people who inject drugs (PWID) is of key public health importance. We aimed to assess the impact of COVID-19 and associated response measures on HIV/HCV prevention services and socio-economic status of PWID in high-HIV-risk sites. Sites with recent (2011-2019) HIV outbreaks among PWID in Europe North America and Israel, that had been previously identified, were contacted early May 2020. Out of 17 sites invited to participate, 13 accepted. Semi-structured qualitative site reports were prepared covering data from March to May 2020, analyzed/coded and confirmed with a structured questionnaire, in which all sites explicitly responded to all 103 issues reported in the qualitative reports. Opioid maintenance treatment, needle/syringe programs and antiretroviral treatment /hepatitis C treatment continued, but with important reductions and operational changes. Increases in overdoses, widespread difficulties with food and hygiene needs, disruptions in drug supply, and increased homelessness were reported. Service programs rapidly reformed long established, and politically entrenched, restrictive service delivery policies. Future epidemic control measures should include mitigation of negative side-effects on service provision and socio-economic determinants in PWID.

Ongoing HIV transmission following a large outbreak among people who inject drugs in Athens, Greece (2014-20)

BACKGROUND AND AIMS

The human immunodeficiency virus (HIV) outbreak among people who inject drugs (PWID) in Athens, Greece in 2011-13 was the largest recent epidemic in Europe and North America. We aimed to assess trends in HIV prevalence, drug use and access to prevention among PWID in Athens to estimate HIV incidence and identify risk factors and to explore HIV-1 dispersal using molecular methods during 2014-20.

METHODS

Two community-based HIV/hepatitis C programmes on PWID were implemented in 2012-13 (n = 3320) and 2018-20 (n = 1635) through consecutive respondent-driven sampling (RDS) rounds. PWID were uniquely identified among rounds/programmes. We obtained RDS-weighted HIV prevalence estimates per round for 2018-20 and compared them to 2012-13. We assessed changes in HIV status, behaviours and access to prevention in PWID participating in both periods. We estimated HIV incidence in a cohort of seronegative PWID as the number of HIV seroconversions/100 person-years during 2014-20 and used Cox regression to identify associated risk factors. Molecular sequencing and phylogenetic analysis were performed in HIV seroconverters.

RESULTS

HIV prevalence per round ranged between 12.0 and 16.2% in 2012-13 and 10.7 and 11.3% in 2018-20 with overlapping 95% confidence intervals (95% CI). Among PWID participating in both programmes, HIV prevalence (95% CI) increased from 14.2% (11.7-17.1%) in 2012-13 to 22.0% (19.0-25.3%) in 2018-20 (P < 0.001). There was a deterioration in socio-economic characteristics such as homelessness [from 16.2% (95% CI = 13.5-19.2%) to 25.6% (22.3-29.0%)], a shift in cocaine use [16.6% (13.9-19.6%) versus 28.1% (24.7-31.7%], reduced access to free syringes [51.8% (48.0-55.7%) versus 44.5% (40.7-48.3%)] and a decrease in daily injecting [36.2% (32.6-39.9%) versus 28.5% (25.2-32.1%)]. HIV incidence (95% CI) in 2014-20 was 1.94 (1.50-2.52) new cases/100 person-years and younger age, lower educational level, larger injection network and daily injecting were risk factors. Almost 9% of HIV seroconversions occurred within a newly expanding phylogenetic cluster.

CONCLUSIONS

In Athens, Greece, compared with the period 2012-13, in the period 2018-20 there was a deterioration in socio-economic conditions among people who inject drugs, an increase in the use of cocaine, reduced access to needle and syringe programmes and stable low levels of human immunodeficiency virus testing. Ongoing human immunodeficiency virus transmission was documented during 2014-20 in existing as well as new transmission clusters.

Epidemiology of HIV infection and associated behaviours among people who inject drugs in England, Wales, and Northern Ireland: Nearly 40 years on

Introduction

People who inject drugs are at high risk of blood‐borne infections. We describe the epidemiology of HIV among people who inject drugs in England, Wales, and Northern Ireland (EW&NI) since 1981.

Methods

National HIV surveillance data were used to describe trends in diagnoses (1981–2019), prevalence (1990–2019), and behaviours (1990–2019) among people who inject drugs aged ≥15 years in EW&NI. HIV care and treatment uptake were assessed among those attending in 2019.

Results

Over the past four decades, the prevalence of HIV among people who inject drugs in EW&NI remained low (range: 0.64%–1.81%). Overall, 4978 people who inject drugs were diagnosed with HIV (3.2% of cases). Diagnoses peaked at 234 in 1987, decreasing to 78 in 2019; the majority were among white men born in the UK/Europe (90%), though the epidemic diversified over time. Late diagnosis (CD4 <350 cells/µl) was common (2010–2019: 52% [429/832]). Of those who last attended for HIV care in 2019, 97% (1503/1550) were receiving HIV treatment and 90% (1375/1520) had a suppressed viral load (<200 copies/ml).

HIV testing uptake has steadily increased among people who inject drugs (32% since 1990). However, in 2019, 18% (246/1404) of those currently injecting reported never testing. The proportion of people currently injecting reporting sharing needles/syringes decreased from 1999 to 2012, before increasing to 20% (288/1426) in 2019, with sharing of any injecting equipment at 37% (523/1429).

Conclusion

The HIV epidemic among people who inject drugs in EW&NI has remained relatively contained compared with in other countries, most likely because of the prompt implementation of an effective national harm reduction programme. However, risk behaviours and varied access to preventive interventions among people who inject drugs indicate the potential for HIV outbreaks.

An outbreak of HIV infection among people who inject drugs in northeastern Massachusetts: findings and lessons learned from a medical record review

BACKGROUND

We conducted a medical record review for healthcare utilization, risk factors, and clinical data among people who inject drugs (PWID) in Massachusetts to aid HIV outbreak response decision-making and strengthen public health practice.

SETTING

Two large community health centers (CHCs) that provide HIV and related services in northeastern Massachusetts.

METHODS

Between May and July 2018, we reviewed medical records for 88 people with HIV (PWH) connected to the outbreak. The review period included care received from May 1, 2016, through the date of review. Surveillance data were used to establish date of HIV diagnosis and assess viral suppression.

RESULTS

Sixty-nine (78%) people had HIV infection diagnosed during the review period, including 10 acute infections. Persons had a median of 3 primary care visits after HIV diagnosis and zero before diagnosis. During the review period, 72% reported active drug or alcohol use, 62% were prescribed medication assisted treatment, and 41% were prescribed antidepressants. The majority (68, 77%) had a documented ART prescription. HIV viral suppression at < 200 copies/mL was more frequent (73%) than the overall across the State (65%); it did not correlate with any of the sociodemographic characteristics studied in our population. Over half (57%) had been hospitalized at least once during the review period, and 36% had a bacterial infection at hospitalization.

CONCLUSIONS

Medical record review with a field investigation of an outbreak provided data about patterns of health care utilization and comorbidities not available from routine HIV surveillance or case interviews. Integration of HIV screening with treatment for HIV and SUD can strengthen prevention and care services for PWID in northeastern Massachusetts.

Crossroads of Drug Abuse and HIV Infection: Neurotoxicity and CNS Reservoir

Drug abuse is a common comorbidity in people infected with HIV. HIV-infected individuals who abuse drugs are a key population who frequently experience suboptimal outcomes along the HIV continuum of care. A modest proportion of HIV-infected individuals develop HIV-associated neurocognitive issues, the severity of which further increases with drug abuse. Moreover, the tendency of the virus to go into latency in certain cellular reservoirs again complicates the elimination of HIV and HIV-associated illnesses. Antiretroviral therapy (ART) successfully decreased the overall viral load in infected people, yet it does not effectively eliminate the virus from all latent reservoirs. Although ART increased the life expectancy of infected individuals, it showed inconsistent improvement in CNS functioning, thus decreasing the quality of life. Research efforts have been dedicated to identifying common mechanisms through which HIV and drug abuse lead to neurotoxicity and CNS dysfunction. Therefore, in order to develop an effective treatment regimen to treat neurocognitive and related symptoms in HIV-infected patients, it is crucial to understand the involved mechanisms of neurotoxicity. Eventually, those mechanisms could lead the way to design and develop novel therapeutic strategies addressing both CNS HIV reservoir and illicit drug use by HIV patients.

Soft Tissue, Bone, and Joint Infections in People Who Inject Drugs

Infections are a common complication among people who inject drugs (PWID). Skin and soft tissue infections (SSTI) as well as bone and joint infections comprise a significant source of morbidity and mortality among this population. The appropriate recognition and management of these infections are critical for providers, as is familiarity with harm-reduction strategies. This review provides an overview of the presentation and management of SSTI and bone and joint infections among PWID, as well as key prevention measures that providers can take.

Drug Injection-Related Norms and High-Risk Behaviors of People Who Inject Drugs in Athens, Greece

Drug use involves social interactions. Therefore, norms in the proximal environment of people who inject drugs (PWID) can favor behaviors that may result in HIV transmission. This work aimed at studying drug injection-related norms and their potential association with risky behaviors among PWID in Athens, Greece, in the context of economic recession and political activism that followed the fiscal crisis and soon after a recent HIV outbreak had leveled off. The Transmission Reduction Intervention Project (TRIP) was a social network-based approach (June 2013 to July 2015) that involved two groups of PWID seeds-with recent HIV infection and with long-term HIV infection and one control group of HIV-negative PWID. Network contacts of seeds were also enrolled. TRIP participants answered a questionnaire that included items on injection-related norms and behaviors. TRIP recruited 320 PWID (HIV positive, 44.4%). TRIP participants, especially those without HIV, often recalled or perceived as normative among their partners and in their networks some behaviors that can lead to HIV transmission. TRIP participants who recalled that they were encouraged by their regular drug partners to use an unclean syringe were almost twice as likely to report that they share syringes [odds ratio (OR) = 2.03; 95% confidence interval (CI) = 1.86-2.21], or give syringes to someone else (OR = 1.70; 95% CI = 1.42-2.04) as those who did not recall such an encouragement. Associations were modified by HIV status. HIV negatives, who were reportedly encouraged to share nonsyringe injecting equipment, were almost 4.5 times as likely to share that material as HIV-negative participants who were not encouraged (OR = 4.59, 95% CI = 4.12-5.11). Further research is needed on the multiple determinants (social, economic, and political) of norms in the social environments of PWID. Since peer norms are associated with risky behaviors, interventions should be developed to encourage norms and peer pressure against the sharing of injection equipment.

Molecular Epidemiological Analysis of the Origin and Transmission Dynamics of the HIV-1 CRF01_AE Sub-Epidemic in Bulgaria

HIV-1 subtype CRF01_AE is the second most predominant strain in Bulgaria, yet little is known about the molecular epidemiology of its origin and transmissibility. We used a phylodynamics approach to better understand this sub-epidemic by analyzing 270 HIV-1 polymerase (pol) sequences collected from persons diagnosed with HIV/AIDS between 1995 and 2019. Using network analyses at a 1.5% genetic distance threshold (d), we found a large 154-member outbreak cluster composed mostly of persons who inject drugs (PWID) that were predominantly men. At d = 0.5%, which was used to identify more recent transmission, the large cluster dissociated into three clusters of 18, 12, and 7 members, respectively, five dyads, and 107 singletons. Phylogenetic analysis of the Bulgarian sequences with publicly available global sequences showed that CRF01_AE likely originated from multiple Asian countries, with Vietnam as the likely source of the outbreak cluster between 1988 and 1990. Our findings indicate that CRF01_AE was introduced into Bulgaria multiple times since 1988, and infections then rapidly spread among PWID locally with bridging to other risk groups and countries. CRF01_AE continues to spread in Bulgaria as evidenced by the more recent large clusters identified at d = 0.5%, highlighting the importance of public health prevention efforts in the PWID communities.

Implementation and evaluation of an educational intervention for safer injection in people who inject drugs in Europe: a multi-country mixed-methods study

BACKGROUND

Harm reduction (HR) interventions are essential to reduce human immunodeficiency virus (HIV) and hepatitis C virus (HCV) transmission in people who inject drugs (PWID). Preliminary testing of the Individually Tailored Support and Education for Safer Injection (ITSESI) evidence-based educational intervention for PWID was performed in France in 2011. We created the Eurosider project to implement and evaluate ITSESI at a wider European level, with a view to its future pan-European diffusion.

METHODS

We performed a mixed-methods study involving quantitative (a 6-month before-after study with PWID) and qualitative (focus groups with field workers) components. The study was conducted in 2018-2019 with 307 eligible PWID participating in four existing HR programmes in Bulgaria, Greece, Portugal, and Romania. ITSESI consists in trained field workers observing PWID injection practices and providing an educational exchange. For the present study, PWID participants were allocated to either the control group (i.e., they continued receiving only the current HR services) or the intervention group (i.e., current HR services plus ITSESI). We used the RE-AIM QuEST framework to assess the effectiveness of ITSESI and its acceptability by field workers. Effectiveness was defined as a reduction in both syringe sharing - the highest HIV/HCV transmission risk practice - and in cutaneous abscesses. We used a multivariable mixed logit model to analyse both effectiveness outcomes and to provide adjusted odds ratios (aOR) and 95% confidence intervals (CI). Field workers' acceptability of the intervention was described using a thematic analysis of the qualitative data.

RESULTS

Of the 307 PWID, 55% received ITSESI. Syringe sharing and cutaneous abscesses decreased during follow-up in the intervention group (from 25 to 16% and from 27 to 14%, respectively). Reductions were smaller in the control group (from 29 to 24% and from 23 to 18%, respectively). The multivariable analyses confirmed the effect of the intervention on both of these outcomes (aOR [95% CI]: 0.38 [0.17, 0.85]) and (aOR [95% CI]: 0.38 [0.16, 0.90], respectively). Our qualitative data on acceptability showed the feasibility of involving field workers as proactive research partners in making ITSESI more accessible and acceptable across Europe.

CONCLUSIONS

We demonstrated both the effectiveness of ITSESI in reducing syringe sharing and cutaneous abscesses in four European countries, and a high level of intervention acceptability by field workers. Our findings provide important insights into how ITSESI can be adapted for pan-European implementation.

HIV outbreaks among people who inject drugs in Europe, North America, and Israel

During 2011-16, HIV outbreaks occurred among people who inject drugs (PWID) in Canada (southeastern Saskatchewan), Greece (Athens), Ireland (Dublin), Israel (Tel Aviv), Luxembourg, Romania (Bucharest), Scotland (Glasgow), and USA (Scott County, Indiana). Factors common to many of these outbreaks included community economic problems, homelessness, and changes in drug injection patterns. The outbreaks differed in size (from under 100 to over 1000 newly reported HIV cases among PWID) and in the extent to which combined prevention had been implemented before, during, and after the outbreaks. Countries need to ensure high coverage of HIV prevention services and coverage higher than the current UNAIDS recommendation might be needed in areas in which short acting drugs are injected. In addition, monitoring of PWID with special attention for changing drug use patterns, risk behaviours, and susceptible subgroups (eg, PWID experiencing homelessness) needs to be in place to prevent or rapidly detect and contain new HIV outbreaks.

High-risk behaviors and their association with awareness of HIV status among participants of a large-scale prevention intervention in Athens, Greece

Background

Aristotle was a seek-test-treat intervention during an outbreak of human immunodeficiency virus (HIV) infection among people who inject drugs (PWID) in Athens, Greece that started in 2011. The aims of this analysis were: (1) to study changes of drug injection-related and sexual behaviors over the course of Aristotle; and (2) to compare the likelihood of risky behaviors among PWID who were aware and unaware of their HIV status.

Methods

Aristotle (2012–2013) involved five successive respondent-driven sampling rounds of approximately 1400 PWID each; eligible PWID could participate in multiple rounds. Participants were interviewed using a questionnaire, were tested for HIV, and were classified as HIV-positive aware of their status (AHS), HIV-positive unaware of their status (UHS), and HIV-negative. Piecewise linear generalized estimating equation models were used to regress repeatedly measured binary outcomes (high-risk behaviors) against covariates.

Results

Aristotle recruited 3320 PWID (84.5% males, median age 34.2 years). Overall, 7110 interviews and blood samples were collected. The proportion of HIV-positive first-time participants who were aware of their HIV infection increased from 21.8% in round A to 36.4% in the last round. The odds of dividing drugs at least half of the time in the past 12 months with a syringe someone else had already used fell from round A to B by 90% [Odds Ratio (OR) (95% Confidence Interval-CI): 0.10 (0.04, 0.23)] among AHS and by 63% among UHS [OR (95% CI): 0.37 (0.19, 0.72)]. This drop was significantly larger (p = 0.02) among AHS. There were also decreases in frequency of injection and in receptive syringe sharing in the past 12 months but they were not significantly different between AHS (66 and 47%, respectively) and UHS (63 and 33%, respectively). Condom use increased only among male AHS from round B to the last round [OR (95% CI): 1.24 (1.01, 1.52)].

Conclusions

The prevalence of risky behaviors related to drug injection decreased in the context of Aristotle. Knowledge of HIV infection was associated with safer drug injection-related behaviors among PWID. This highlights the need for comprehensive interventions that scale-up HIV testing and help PWID become aware of their HIV status.