Gender Differences in HIV, HCV risk and Prevention Needs Among People who Inject drug in Vietnam.

We examined gender differences among people who inject drug (PWID) in Hai Phong, Vietnam in term of blood-borne infections, risk behaviors, and access to care. Using respondent-driven-sampling surveys, we recruited 3146 PWID from 2016 to 2018. Inclusion criteria included a positive urine test for heroin and recent injection marks. There were 155 female PWID (4,9%), including 82 at RDS-2016, 32 at RDS-2017 and 38 at RDS-2018. The age mean was 36.3 ± 7.2 years. The majority of female PWID had less than high school education (90.9%) and were unemployed (51.3%). There was no difference in the proportion of HIV and HCV positive by gender. However, women had several significant differences in risk behaviors than men in multivariable logistic regression. Being a woman was independently associated with being unemployed, being a sex worker, having unstable housing, having uses drugs for less than 5 years, more use of methamphetamine, having a partner who ever injected drugs, and less access to methadone treatment. Interventions targeting female PWID are needed, possibly through community organizations and peer educators.

Rapid point-of-care (POC) testing for Hepatitis C antibodies in a very high prevalence setting: persons injecting drugs in Tallinn, Estonia.

BACKGROUND: Between December 2018 and January of 2019, we evaluated the accuracy of the point-of-care Hepatitis C (HCV) antibody test (POC; OraQuick HCV) used at a community-based needle and syringe exchange program serving persons who inject drugs in Tallinn, Estonia. METHODS: We compared the results of screening for HCV antibodies by OraQuick (oral swab) and enzyme immunoassay (EIA; blood draw) and assessed test results implications in a high prevalence setting. Findings Of the 100 participants, 88 (88%) had reactive POC test results, and 93 were HCV antibody positive on EIA testing. Sensitivity, specificity and negative predictive value (NPV) for the POC assay with EIA as the relevant reference test were as follows: 94.6% (95% CI 90.0-99.2%), 100% and 58.3% (95% CI 30.4-86.2%). Of the 12 testing, HCV-negative with the POC only 7 (58.3%) were true negatives. CONCLUSIONS: Oral swab rapid testing HCV screening in this nonclinical setting was sensitive and specific but had unacceptably low NPV. In high prevalence settings, POC tests with high sensitivity and that directly measure HCV RNA may be warranted.

HIV Treatment Knowledge in the Context of "Treatment as Prevention" (TasP).

According to 2012 universal ART guidelines, as part of "treatment as prevention" (TasP), all people living with HIV (PLWH) should immediately initiate antiretroviral therapy post-diagnosis to facilitate viral suppression. PLWH who are virally suppressed have no risk of sexually transmitting HIV. This study used descriptive analysis of quantitative data (N = 99) and thematic analysis of qualitative interviews (n = 36) to compare participants recruited from a hospital-based detoxification (detox) unit, largely diagnosed with HIV pre-2012 (n = 63) vs. those recruited from public, urban sexual health clinics (SHCs), mainly diagnosed in 2012 or later (n = 36). Detox participants were significantly more knowledgeable than SHC participants about HIV treatment, except regarding TasP. SHC participants' desire for rapid linkage to care and ART initiation was in line with 2012 universal ART guidelines and TasP messaging regarding viral suppression. More targeted messaging to PLWH pre-2012 could ensure that all PLWH benefit from scientific advances in HIV treatment.

DSM-5 substance use disorder symptom clusters and HIV antiretroviral therapy (ART) adherence.

This study examines self-reported 30-day antiretroviral therapy (ART) adherence among 101 people living with HIV and substance use disorders (SUD) in New York City in terms of Diagnostic and Statistical Manual - 5th Edition (DSM-5) SUD symptom clusters: impaired control, social impairment, risky use and pharmacological criteria. Overall, 60.4% met DSM-5 criteria for stimulant, 55.5% for alcohol, 34.7% for cannabis and 25.7% for opioid SUD. Of the 76 participants with a current ART prescription, 75.3% reported at least 90% 30-day adherence. Participants with vs. without alcohol SUD were significantly less likely to report ART adherence (64.3% vs. 88.2%, p = .017). Endorsement of social impairment significantly differed among adherent vs. non-adherent participants with alcohol SUDs (74.1% vs. 100%, p = .038) and with opioid SUDs (94.1% vs. 50.0%, p = .040). Understanding specific SUD symptom clusters may assist providers and patients in developing strategies to improve ART adherence.

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.

Feasibility of a simple and scalable cognitive-behavioral intervention to treat problem substance use.

OBJECTIVE: Our proof-of-concept study tested a simple cognitive-behavioral strategy based on experimental psychology research that draws on the concept of self-distancing and is consistent with mindfulness principles - using non-first person self-talk when facing substance use cues or cravings -- to help people achieve substance use goals. We evaluated participants' understanding, use, and utility of the intervention at follow-up. METHOD: We recruited 17 New York City residents who used drugs. At baseline, we collected demographic and substance use data and conducted the intervention. At one-week follow-up, participants were asked about their understanding, use, and perceived utility of the intervention, and asked to complete an anonymous five-item assessment of the intervention. RESULTS: Sixteen participants completed follow-up. Understanding was judged "acceptable" or better for 15; 11 used their scripts during follow-up; four described their scripts as very useful, one as moderately, five as a little, and one as not useful. Nine returned assessments; ratings were strongly favorable. CONCLUSIONS: Results from our pilot are encouraging and point to further research on this intervention. The intervention is suitable for integration into longer-term therapy and we envision non-first person self-talk as one strategy alongside others individuals can employ to moderate their substance use.

"It's Never Just About the HIV:" HIV Primary Care Providers' Perception of Substance Use in the Era of "Universal" Antiretroviral Medication Treatment.

Antiretroviral therapy (ART) is recommended for all people living with HIV (PLWH), regardless of disease status. Substance use disorders (SUD) are common barriers to successful HIV treatment; however, few studies have comprehensively explored how HIV primary care providers take SUDs into account in the context of universal ART implementation. This study uses thematic analysis of qualitative interviews to explore providers' (N = 25) substance use assessment and factors associated with ART initiation. 64% of providers had 15 or more years of HIV treatment experience. Almost all providers agreed with the guidelines for universal ART initiation despite the presence of SUD. Still, identification and management of SUD is challenged by inconsistent assessment, providers' misperceptions about SUD and patients' willingness to discuss it, and lack of accessible treatment resources when SUD is identified. Greater guidance in systematic SUD assessment and management, combined with integrated addiction services, could enhance universal ART implementation among PLWH/SUD.

Risk Behaviors for HIV and HCV Infection Among People Who Inject Drugs in Hai Phong, Viet Nam, 2014.

We examined the potential for HIV and hepatitis C (HCV) transmission across persons who inject drugs (PWID), men-who-have-sex-with-men (MSM) and female commercial sex workers (CSW) PWID and the potential for sexual transmission of HIV from PWID to the general population in Hai Phong, Viet Nam. Using respondent driven and convenience sampling we recruited 603 participants in 2014. All participants used heroin; 24% used non-injected methamphetamine. HIV prevalence was 25%; HCV prevalence was 67%. HIV infection was associated with HCV prevalence and both infections were associated with length of injecting career. Reported injecting risk behaviors were low; unsafe sexual behavior was high among MSM-PWID and CSW-PWID. There is strong possibility of sexual transmission to primary partners facilitated by methamphetamine use. We would suggest future HIV prevention programs utilize multiple interventions including "treatment as prevention" to potential sexual transmission of HIV among MSM and CSW-PWID and from PWID to the general population.

Another frontier for harm reduction: contraceptive needs of females who inject drugs in Estonia, a cross-sectional study.

BACKGROUND: Despite increasing contraceptive availability, unintended pregnancy remains a global problem. Developing strategies to reverse this trend and increasing occurrence of withdrawal syndrome among newborn children of females currently injecting drugs warrants special attention. The knowledge base on the uptake of effective contraception among females who inject drugs (FWID) is scant. We aimed to examine the prevalence of and factors associated with the use of non-condom contraceptives among sexually active FWID with the focus on effective contraception. METHODS: In a series of cross-sectional studies (2007-2013), 265 current FWID were recruited through respondent-driven sampling (RDS), interviewed, and tested for HIV. RDS weights were used to estimate the prevalence of effective contraception (hormonal contraception, intrauterine device, sterilization) use in the last 6 months. RESULTS: Of the sexually active women with main partners (n = 196) 4.8% (95% CI 2.3-9.7) were using effective contraception, 52.7% (95% CI 42.5-62.7) less-effective or no contraception. 42.5% (95% CI 32.7-52.9) relied on condoms for contraception. The odds for using effective contraception were higher among women with > 10 years of education (OR 7.29, 95% CI 1.4-38.8). None of the women lacking health insurance (n = 84) were using effective contraception. CONCLUSIONS: The very low coverage with effective contraception highlights the need to improve contraceptive services for FWID. Reproductive health service including contraception should be considered essential components of harm reduction and of comprehensive prevention and care for HIV among persons who use drugs.

Rapid Decline in HIV Incidence Among Persons Who Inject Drugs During a Fast-Track Combination Prevention Program After an HIV Outbreak in Athens.

Background: A "seek-test-treat" intervention (ARISTOTLE) was implemented in response to an outbreak of human immunodeficiency virus (HIV) infection among persons who inject drugs (PWID) in Athens. We assess trends in HIV incidence, prevalence, risk behaviors and access to prevention/treatment. Methods: Methods included behavioral data collection, provision of injection equipment, HIV testing, linkage to opioid substitution treatment (OST) programs and HIV care during 5 rounds of respondent-driven sampling (2012-2013). HIV incidence was estimated from observed seroconversions. Results: Estimated coverage of the target population was 88% (71%-100%; 7113 questionnaires/blood samples from 3320 PWID). The prevalence of HIV infection was 16.5%. The incidence per 100 person-years decreased from 7.8 (95% confidence interval, 4.6-13.1) (2012) to 1.7 (0.55-5.31) (2013; P for trend = .001). Risk factors for seroconversion were frequency of injection, homelessness, and history of imprisonment. Injection at least once daily declined from 45.2% to 18.8% (P < .001) and from 36.8% to 26.0% (P = .007) for sharing syringes, and the proportion of undiagnosed HIV infection declined from 84.3% to 15.0% (P < .001). Current OST increased from 12.2% to 27.7% (P < .001), and 48.4% of unlinked seropositive participants were linked to HIV care through 2013. Repeat participants reported higher rates of adequate syringe coverage, linkage to HIV care and OST. Conclusions: Multiple evidence-based interventions delivered through rapid recruitment in a large proportion of the population of PWID are likely to have helped mitigate this HIV outbreak.

Homelessness and Other Risk Factors for HIV Infection in the Current Outbreak Among Injection Drug Users in Athens, Greece.

Objectives. We examined HIV prevalence and risk factors among injection drug users (IDUs) in Athens, Greece, during an HIV outbreak. Methods. We used respondent-driven sampling (RDS) to recruit 1404 IDUs to the Aristotle intervention in August to October 2012. We interviewed participants and tested for HIV. We performed bivariate and multivariate analyses. Results. Estimated HIV prevalence was 19.8% (RDS-weighted prevalence = 14.8%). Odds of infection were 2.3 times as high in homeless as in housed IDUs and 2.1 times as high among IDUs who injected at least once per day as among less frequent injectors (both, P < .001). Six percent of men and 23.5% of women reported transactional sex in the past 12 months, and condom use was low. Intercourse with non-IDUs was common (53.2% of men, 25.6% of women). Among IDUs who had been injecting for 2 years or less the estimated incidence rate was 23.4 new HIV cases per 100 person-years at risk. Conclusions. Efforts to reduce HIV transmission should address homelessness as well as scaling up prevention services, such as needle and syringe distribution and other risk reduction interventions.

Incidence and prevalence of hepatitis C in prisons and other closed settings: results of a systematic review and meta-analysis.

UNLABELLED: People detained in prisons and other closed settings are at elevated risk of infection with hepatitis C virus (HCV). We undertook a systematic review and meta-analysis with the aim of determining the rate of incident HCV infection and the prevalence of anti-HCV among detainees in closed settings. We systematically searched databases of peer-reviewed literature and widely distributed a call for unpublished data. We calculated summary estimates of incidence and prevalence among general population detainees and detainees with a history of injection drug use (IDU), and explored heterogeneity through stratification and meta-regression. The summary prevalence estimates were used to estimate the number of anti-HCV positive prisoners globally. HCV incidence among general detainees was 1.4 per 100 person-years (py; 95% confidence interval [CI]: 0.1, 2.7; k = 4), and 16.4 per 100 py (95% CI: 0.8, 32.1; k = 3) among detainees with a history of IDU. The summary prevalence estimate of anti-HCV in general detainees was 26% (95% CI: 23%, 29%; k = 93), and in detainees with a history of IDU, 64% (95% CI: 58%, 70%; k = 51). The regions of highest prevalence were Central Asia (38%; 95% CI 32%, 43%; k = 1) and Australasia (35%; 95% CI: 28%, 43%; k = 9). We estimate that 2.2 million (range: 1.4-2.9 million) detainees globally are anti-HCV positive, with the largest populations in North America (668,500; range: 553,500-784,000) and East and Southeast Asia (638,000; range: 332,000-970,000). CONCLUSION: HCV is a significant concern in detained populations, with one in four detainees anti-HCV-positive. Epidemiological data on the extent of HCV infection in detained populations is lacking in many countries. Greater attention towards prevention, diagnosis, and treatment of HCV infection among detained populations is urgently required.

Smoking characteristics and comorbidities in the power to quit randomized clinical trial for homeless smokers.

INTRODUCTION: Smoking prevalence in homeless populations is strikingly high (∼70%); yet, little is known about effective smoking cessation interventions for this population. We conducted a community-based clinical trial, Power To Quit (PTQ), to assess the effects of motivational interviewing (MI) and nicotine patch (nicotine replacement therapy [NRT]) on smoking cessation among homeless smokers. This paper describes the smoking characteristics and comorbidities of smokers in the study. METHODS: Four hundred and thirty homeless adult smokers were randomized to either the intervention arm (NRT + MI) or the control arm (NRT + Brief Advice). Baseline assessment included demographic information, shelter status, smoking history, motivation to quit smoking, alcohol/other substance abuse, and psychiatric comorbidities. RESULTS: Of the 849 individuals who completed the eligibility survey, 578 (68.1%) were eligible and 430 (74.4% of eligibles) were enrolled. Participants were predominantly Black, male, and had mean age of 44.4 years (S D = 9.9), and the majority were unemployed (90.5%). Most participants reported sleeping in emergency shelters; nearly half had been homeless for more than a year. Nearly all the participants were daily smokers who smoked an average of 20 cigarettes/day. Nearly 40% had patient health questionnaire-9 depression scores in the moderate or worse range, and more than 80% screened positive for lifetime history of drug abuse or dependence. CONCLUSIONS: This study demonstrates the feasibility of enrolling a diverse sample of homeless smokers into a smoking cessation clinical trial. The uniqueness of the study sample enables investigators to examine the influence of nicotine dependence as well as psychiatric and substance abuse comorbidities on smoking cessation outcomes.

Non-fatal drug overdose among persons who inject drugs during first two years of the COVID-19 pandemic in New York City: Prevalence, risk factors.

Background: We examined non-fatal drug overdoses during the COVID-19 pandemic among persons who inject drugs (PWID) in New York City (NYC). Methods: We recruited 275 PWID through respondent driven sampling and staff outreach from Oct. 2021-Sept. 2022 and enrolled in a cross-sectional survey. Information was collected on demographics, drug use behaviors, overdose experiences, substance use treatment history and strategies for coping with overdose threat. We compared PWID who did and did not experience non-fatal overdoses during lifetime and during the COVID-19 pandemic. Results: Participants were 71% male, and the mean age was 49 (SD 10). Heroin was the most frequently reported drug used (79%), 82% were fentanyl positive at enrollment urinalysis, 60% had overdosed in their lifetime and 34% had overdosed during the COVID-19 pandemic. In multivariable logistic regression, having previous overdosed, having a received a psychiatric diagnosis, and having a regular group of injectors were independently associated with experiencing an overdose during the pandemic. Overdose during the pandemic was unexpectedly high (approximately 30%) among persons reporting less than daily use of their main drug. Among PWID, 95% reported practicing at least one and 75% at least two overdose coping strategies. Practicing the different strategies, however, was generally not associated with a lower probability of experiencing an overdose. Conclusions: There has been a high rate of non-fatal overdoses among PWID in NYC during the pandemic. Fentanyl is almost ubiquitous in the drug supply in the city. PWID coping strategies are not yet providing strong protective effects against non-fatal overdose.

Understanding intentionality of fentanyl use and drug overdose risk: Findings from a mixed methods study of people who inject drugs in New York City.

BACKGROUND: As the proportion of drug overdose deaths involving fentanyl continues to increase in the US, monitoring exposure to and possible changes in intention to use fentanyl among people who use drugs (PWUD) is of great public health importance. This mixed methods study examines intentionality of fentanyl use among persons who inject drugs (PWID) in New York City during a period of unprecedently high rates of drug overdose mortality. METHODS: Between October 2021 and December 2022, N = 313 PWID were enrolled in a cross-sectional study that included a survey and urine toxicology screening. A subset of N = 162 PWID also participated in an in-depth interview (IDI) examining drug use patterns, including fentanyl use and experiences with drug overdose. RESULTS: 83% of PWID were urine-toxicology positive for fentanyl, though only 18% reported recent intentional fentanyl use. Intentionality of fentanyl use was associated with being younger, white, increased drug use frequency, recent overdose (OD), recent stimulant use, among other characteristics. Qualitative findings suggest PWID tolerance to fentanyl may be increasing, which could result in an increased preference for fentanyl. Concern about overdose was common with nearly all PWID using overdose prevention strategies to avoid it. CONCLUSION: The findings from this study demonstrate a high prevalence of fentanyl use among PWID in NYC, despite an expressed preference for heroin. Our results suggest that the pervasiveness of fentanyl may be increasing fentanyl use and tolerance, which may contribute to an increased risk for drug overdose. Expanding access to existing evidence-based interventions such as naloxone and medications for opioid use disorder is necessary to reduce overdose mortality. Further, exploring the implementation of additional novel strategies to reduce the risk of drug overdose should be considered, including other forms of opioid maintenance treatment and expansion and government support for overdose prevention centers.

Global epidemiology of abortion among female sex workers: a systematic review, meta-analysis, and meta-regression.

PURPOSE: Despite the evidence of a high rate of unintended pregnancy, there remains limited information about the prevalence and experiences of abortion among female sex workers (FSWs). In response, we aimed to summarize the available evidence on abortion among FSWs. METHODS: We searched Medline, Embase, PsycINFO, CINAHL, Scopus, and Web of Science from inception to January 29, 2023 . We pooled data from the included studies using random-effects meta-analyses. We also grouped countries for the legality of elective abortion stratified by the United Nations database on abortion laws and policies. RESULTS: We identified 60 eligible studies from 2031 potentially eligible records. The pooled lifetime prevalence of at least one and multiple induced abortions was 37.7% (95% confidence interval, 31.8-43.7) and 21.7% (14.9-29.2), respectively. Among FSWs recruited in countries where elective abortion is illegal, at least one induced abortion prevalence was 35.1% (28.1-42.4), and multiple induced abortion prevalence was 23.1% (12.4-35.9). In countries where elective abortion is legal, at least one induced abortion prevalence was 44.6% (34.8-54.6), and multiple induced abortion prevalence was 19.9% (11.9-29.3). Among FSWs experiencing abortion, self-managed abortion prevalence was estimated at 32.8% (23.6-42.7) overall, 42.8% (37.2-48.5) for countries where elective abortion is illegal, and 15.6% (3.9-32.7) for countries that legally allow elective abortion. CONCLUSIONS: Induced abortion is prevalent among FSWs, highlighting the need for interventions to increase access to effective contraception and safe abortion care. While induced abortion prevalence did not significantly differ across the legal grounds for abortion, self-managed abortion prevalence was higher in countries where elective abortion was illegal, highlighting the urgent need for accessible abortion services for FSWs in criminalized settings. Moving forward necessitates implementing and evaluating culturally acceptable models of safe abortion and post-abortion care for FSWs to increase access to the full spectrum of sexual and reproductive health services.

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.

Modeling HIV transmission among persons who inject drugs (PWID) at the "End of the HIV Epidemic" and during the COVID-19 pandemic.

BACKGROUND: We explore injecting risk and HIV incidence among PWID in New York City (NYC), from 2012 to 2019, when incidence was extremely low, <0.1/100 person-years at risk, and during disruption of prevention services due to the COVID-19 pandemic. METHODS: We developed an Agent-Based model (ABM) to simulate sharing injecting equipment and measure HIV incidence in NYC. The model was adapted from a previous ABM model developed to compare HIV transmission with "high" versus "low" dead space syringes. Data for applying the model to NYC during the period of very low HIV incidence was taken from the "Risk Factors" study, a long-running study of participants entering substance use treatment in NYC. Injecting risk behavior had not been eliminated in this population, with approximately 15 % reported recent syringe sharing. Data for possible transmission during COVID-19 disruption was taken from previous HIV outbreaks and early studies of the pandemic in NYC. RESULTS: The modeled incidence rates fell within the 95 % confidence bounds of all of the empirically observed incidence rates, without any additional calibration of the model. Potential COVID-19 disruptions increased the probability of an outbreak from 0.03 to 0.25. CONCLUSIONS: The primary factors in the very low HIV incidence were the extremely small numbers of PWID likely to transmit HIV and that most sharing occurs within small, relatively stable, mostly seroconcordant groups. Containing an HIV outbreak among PWID during a continuing pandemic would be quite difficult. Pre-pandemic levels of HIV prevention services should be restored as quickly as feasible.

A community-based intervention to decrease the prevalence of HIV viremia among people who inject drugs in Vietnam.

Background: In most low-to-middle-income countries, HIV control at the population level among people who inject drugs (PWID) remains a major challenge. We aimed to demonstrate that an innovative intervention can identify HIV-positive PWID in the community who are not treated efficiently, and get them treated efficiently. Methods: Between 2016 and 2020, we implemented an intervention consisting of mass HIV screening of PWID using three annual respondent-driven sampling surveys (RDSS) and a post-intervention evaluation RDSS in community-based organisation (CBO) sites, coupled with peer support to facilitate/improve access to antiretroviral and methadone therapy in Haiphong, Vietnam. The primary outcome was the proportion of identified uncontrolled HIV-positive PWID who achieved viral control. We also estimated the potential effect of the intervention on the proportion of PWID with HIV RNA >1000 copies/mL among all PWID during the study period. Findings: Over the three RDSS, 3150 different PWID were screened, i.e. two-thirds of the estimated population size. They all injected heroin, their median age was of 39 years, 95% were male, 26.5% were HIV-infected, and 78.6% of the latter had HIV RNA ≤1000 copies/mL. Among the 177 PWID identified with an unsuppressed viral load, 73 (41.2%) achieved viral suppression at the final visit. HIV viremia decreased from 7.2% at baseline to 2.9% at the final RDSS (p<0.001). Up to 42% of this observed reduction may be explained by the intervention, in the absence of any external intervention targeting PWID during the study period. Interpretation: Mass community-based screening using RDSS coupled with CBO support is a powerful tool to rapidly identify untreated HIV-positive PWID and (re)link them to care. Funding: NIDA (USA) and ANRS (France).