Recent fentanyl use among people who inject drugs: Results from a rapid assessment in Baltimore, Maryland

The Fourth Wave of the Opioid Epidemic: Increasing Combination of Fentanyl With Stimulants

Objectives. To identify drug prevalence through the analysis of drug material and paraphernalia (DMP) collected from scenes of fentanyl-involved fatal accidental drug overdoses in San Francisco, California, throughout 2022. Methods. We conducted gas chromatography-mass spectrometry testing on 409 items of DMP (e.g., glass pipes, syringes, aluminum foil, powders) from 137 cases, and we further tested 132 DMP items using liquid chromatography-tandem mass spectrometry in context with decedent information and toxicology findings. Results. We detected fentanyl in 106 cases (77%); 35 (33%) contained fentanyl either alone or with fentanyl precursors or breakdown products. Of the 106 fentanyl-positive cases, we codetected cocaine in 29 (27%) and methamphetamine in 16 (15%). Overall, we detected methamphetamine in 58 (42%) cases (25 in isolation), cocaine in 68 (50%) cases (18 in isolation), and fentanyl analogs in 33 (24%) cases (4 in isolation). We detected 38 novel fentanyl analogs and precursors of analogs. Conclusions. We observed fentanyl use in combination with stimulants (a characteristic pattern of the opioid epidemic fourth wave). Smoking fentanyl powder using aluminum foil or snorting were the most inferred. We established polysubstance use and emerging potent novel fentanyl analogs use. (Am J Public Health. 2025;115(4):555-565. https://doi.org/10.2105/AJPH.2024.307948).

Correlates of fentanyl preference among people who use drugs in Rhode Island

BACKGROUND

Fentanyl is increasingly pervasive in the unregulated drug supply and is a driver of drug overdose deaths in the United States. The aims of this study were to characterize and identify correlates of fentanyl preference among people who use drugs (PWUD) in Rhode Island (RI).

METHODS

Using bivariate analysis, we examined associations between fentanyl preference and sociodemographic and psychosocial characteristics at baseline among participants enrolled in the RI Prescription Drug and Illicit Drug Study from August 2020-February 2023. Fentanyl preference was operationalized based on responses to a five-point Likert scale: "I prefer using fentanyl or drugs that have fentanyl in them." Participants who responded that they "strongly disagree," "disagree," or were "neutral" with respect to this statement were classified as not preferring fentanyl, whereas participants who responded that they "agree" or "strongly agree" were classified as preferring fentanyl.

RESULTS

Among 506 PWUD eligible for inclusion in this analysis, 15% expressed a preference for fentanyl or drugs containing fentanyl as their drug of choice. In bivariate analyses, preference for fentanyl was positively associated with younger age, white race, lifetime history of overdose, history of injection drug use, past month enrollment in a substance use treatment program, past month treatment with medications for opioid use disorder, and preferences for heroin and crystal methamphetamine (all p < 0.05). Descriptive data yielded further insight into reasons for fentanyl preference, the predominant having to do with perceived effects of the drug and desire to avoid withdrawal symptoms.

CONCLUSIONS

Only a relatively small subset of study participants preferred drugs containing fentanyl. Given the increased prevalence of fentanyl contamination across substances within the unregulated drug market, the result for PWUD is increasingly less agency with respect to choice of drug; for example, people may be forced to use fentanyl due to restricted supply and the need to mitigate withdrawal symptoms, or may be using fentanyl without intending to do so. Novel and more effective interventions for PWUD, including increased access to age-appropriate harm reduction programs such as fentanyl test strips and overdose prevention centers, are needed to mitigate fentanyl-related harms.

Structural and social changes due to the COVID-19 pandemic and their impact on engagement in substance use disorder treatment services: a qualitative study among people with a recent history of injection drug use in Baltimore, Maryland

BACKGROUND

Substance use disorder treatment and recovery support services are critical for achieving and maintaining recovery. There are limited data on how structural and social changes due to the COVID-19 pandemic impacted individual-level experiences with substance use disorder treatment-related services among community-based samples of people who inject drugs.

METHODS

People with a recent history of injection drug use who were enrolled in the community-based AIDS Linked to the IntraVenous Experience study in Baltimore, Maryland participated in a one-time, semi-structured interview between July 2021 and February 2022 about their experiences living through the COVID-19 pandemic (n = 28). An iterative inductive coding process was used to identify themes describing how structural and social changes due to the COVID-19 pandemic affected participants' experiences with substance use disorder treatment-related services.

RESULTS

The median age of participants was 54 years (range = 24-73); 10 (36%) participants were female, 16 (57%) were non-Hispanic Black, and 8 (29%) were living with HIV. We identified several structural and social changes due the pandemic that acted as barriers and facilitators to individual-level engagement in treatment with medications for opioid use disorder (MOUD) and recovery support services (e.g., support group meetings). New take-home methadone flexibility policies temporarily facilitated engagement in MOUD treatment, but other pre-existing rigid policies and practices (e.g., zero-tolerance) were counteracting barriers. Changes in the illicit drug market were both a facilitator and barrier to MOUD treatment. Decreased availability and pandemic-related adaptations to in-person services were a barrier to recovery support services. While telehealth expansion facilitated engagement in recovery support group meetings for some participants, other participants faced digital and technological barriers. These changes in service provision also led to diminished perceived quality of both virtual and in-person recovery support group meetings. However, a facilitator of recovery support was increased accessibility of individual service providers (e.g., counselors and Sponsors).

CONCLUSIONS

Structural and social changes across several socioecological levels created new barriers and facilitators of individual-level engagement in substance use disorder treatment-related services. Multilevel interventions are needed to improve access to and engagement in high-quality substance use disorder treatment and recovery support services among people who inject drugs.

Longitudinal patterns of use of stimulants and opioids in the AIDS linked to the IntraVenous experience cohort, 2005-2019

BACKGROUND

Overdoses involving opioids and stimulants are on the rise, yet few studies have examined longitudinal trends in use of both substances. We sought to describe use and co-use of opioids and stimulants, 2005-2019, in the AIDS Linked to the Intravenous Experience (ALIVE) cohort - a community-based cohort of people with a history of injection drug use living in or near Baltimore, MD.

METHODS

We included 2083 ALIVE participants, who had at least two visits during the study period. Our outcome was based on self-reported use of opioids and stimulants in the prior 6 months. We estimated prevalence of 4 categories of use (neither stimulants nor opioids, only stimulants, only opioids, stimulants and opioids), using a non-parametric multi-state model, accounting for the competing event of death and weighting for informative loss to follow-up. All analyses were stratified by enrollment cohort, with the main analysis including participants who enrolled prior to 2015 and a sub-analysis including participants who enrolled 2015-2018.

RESULTS

In the main analysis, prevalence of using stimulants and opioids decreased from 38 % in 2005 to 12 % 2013 but stabilized from 2014 onwards (13-19 %). The prevalence of using only stimulants (7-11 %) and only opioids (5-10 %) was stable across time. Participants who reported using both were more likely to report homelessness, depression, and other substance use (e.g., marijuana and heavy alcohol use) than participants in the other use categories. On average, 65 % of visits with use of both were followed by a subsequent visit with use of both; of participants transitioning out of using both, 13% transitioned to using neither.

CONCLUSIONS

While use of stimulants and opioids declined in the cohort through 2013, a meaningful proportion of participants persistently used both. More research is needed to understand and develop strategies to mitigate harms associated with persistent use of both stimulants and opioids.

Systematic review on intentional non-medical fentanyl use among people who use drugs

Objectives

Fentanyl is a highly potent opioid and has, until recently, been considered an unwanted contaminant in the street drug supply among people who use drugs (PWUD). However, it has become a drug of choice for an increasing number of individuals. This systematic review evaluated intentional non-medical fentanyl use among PWUD, specifically by summarizing demographic variance, reasons for use, and resulting patterns of use.

Methods

The search strategy was developed with a combination of free text keywords and MeSH and non-MeSH keywords, and adapted with database-specific filters to Ovid MEDLINE, Embase, Web of Science, and PsychINFO. Studies included were human studies with intentional use of non-medical fentanyl or analogues in individuals older than 13. Only peer-reviewed original articles available in English were included.

Results

The search resulted in 4437 studies after de-duplication, of which 132 were selected for full-text review. Out of 41 papers included, it was found that individuals who use fentanyl intentionally were more likely to be young, male, and White. They were also more likely to have experienced overdoses, and report injection drug use. There is evidence that fentanyl seeking behaviours are motivated by greater potency, delay of withdrawal, lower cost, and greater availability.

Conclusions

Among PWUD, individuals who intentionally use fentanyl have severe substance use patterns, precarious living situations, and extensive overdose history. In response to the increasing number of individuals who use fentanyl, alternative treatment approaches need to be developed for more effective management of withdrawal and opioid use disorder.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42021272111.

Characterizing Opioid Withdrawal Experiences and Consequences Among a Community Sample of People Who Use Opioids

BACKGROUND

Opioid withdrawal symptoms are a highly salient and consequential health condition experienced by people who use opioids (PWUO). This study utilized qualitative interviews to explore opioid withdrawal experiences and consequences among PWUO in Los Angeles County, USA.

METHODS

Semi-structured qualitative interviews were conducted with 22 PWUO (aged 27-63 years) between May 2021 and May 2022. Participants self-reported opioid and injection drug use in the last 30 days. We employed an inductive thematic approach to systematically code and synthesize textual interview data.

RESULTS

Participants experienced withdrawal symptoms frequently, with many going to great lengths to avoid them. Withdrawal pain was described as incapacitating and interfered with PWUO's ability to sustain regular employment and ensure stable housing. Avoiding withdrawal was described as influential in driving decisions to continue using opioids. Mechanisms for managing withdrawal included using other substances to the point of sedation. PWUO who transitioned from heroin to fentanyl use revealed more frequent, painful, and faster onset of withdrawal symptoms. Adverse withdrawal experiences and fear of precipitated withdrawal from buprenorphine were barriers to treatment initiation and continuation.

CONCLUSION

Withdrawal symptoms among PWUO increase health risk. Improved strategies to treat opioid withdrawal are urgently needed. Solutions such as safe supply and intentional opioid withdrawal interventions (educational trainings, withdrawal comfort kits) are needed to improve withdrawal management and reduce opioid-related harm.

Trends in reported and biologically confirmed drug use among people who use ecstasy in the nightclub/festival-attending population, 2016-2022

Background

Nightclub/festival attendees are a population with high rates of party drug use, but research is needed to determine whether there have been shifts in unintended drug exposure in this population (e.g., via adulterants) to inform prevention and harm reduction efforts.

Methods

Adults entering nightclubs and festivals in New York City were asked about past-year drug use in 2016 through 2022, with a subset providing a hair sample for testing. We focused on the 1943 who reported ecstasy use (of which 247 had a hair sample analyzed) and compared trends in self-reported drug use, drug positivity, and adjusted prevalence (adjusting for unreported use).

Results

MDMA positivity decreased from 74.4 % to 42.3 %, and decreases occurred regarding detection of synthetic cathinones ("bath salts"; a 100.0 % decrease), MDA (a 76.9 % decrease), amphetamine (an 81.3 % decrease), methamphetamine (a 64.2 % decrease), and ketamine (a 33.4 % decrease) (ps < .05). Although prevalence of MDA and synthetic cathinone use was comparable between self-report and adjusted report in 2022, gaps in prevalence were wider in 2016 (ps < .01). Adjusted prevalence of synthetic cathinone use decreased more across time than prevalence based on self-report (a 79.4 % vs. 69.1 % decrease) and adjusted report for MDA use decreased more than prevalence based on self-report (a 50.6 % vs. 38.9 % decrease).

Conclusions

Combining self-report and toxicology tests helped us determine that decreases in drug use/exposure were steeper regarding adjusted prevalence. Underreported drug exposure-possibly due to exposure to adulterants-appears to have had less of an effect on prevalence in 2022 than it did in 2016.

Trends in self-reported non-fatal overdose and patterns of substance use before and during the COVID-19 pandemic in a prospective cohort of adults who have injected drugs - Baltimore, Maryland, 2014-2022

BACKGROUND

Overdose deaths increased during the COVID-19 pandemic in the United States. Less is known about drug use behavior changes during the same time period. We examined differences in non-fatal overdose and drug use behaviors before and after the start of the COVID-19 pandemic in a community-recruited cohort of adults who have injected drugs.

METHODS

721 participants attended 7401 visits between Jan 2014 and Mar 2022. Outcomes (non-fatal overdose, drug route of administration, type of drugs used) were assessed via self-report in the last six months. We compared pre-pandemic (Jan 2014-Mar 2020) to inter-pandemic (Dec 2020-Mar 2022) prevalence of each outcome using Cohcrane-Maentel-Haeszel odds ratios (CMH-OR). We then estimated probabilities for transitioning between specific behaviors from participants' last pre-pandemic visit to their first inter-pandemic visit.

RESULTS

Comparing pre-pandemic visits to inter-pandemic visits, the prevalence of non-fatal overdose did not change (CMH-OR 1.06, 95% CI 0.75-1.50); the prevalence of injection (CMH-OR 0.13, 95% CI 0.1-0.17) and non-injection (CMH-OR 0.51, 95% CI 0.42-0.61) drug use declined. More than a third (35.7%) of persons using both injection and non-injection drugs pre-pandemic transitioned to exclusive non-injection use during the pandemic. By contrast, few (4.0%) persons using non-injection drugs exclusively pre-pandemic transitioned to injecting during the pandemic.

CONCLUSION

Among adults who have injected drugs, the start of the COVID-19 pandemic was associated with a reduced drug use prevalence and transitions from injection to non-injection use. Average overdose prevalence was unchanged, but these behavior changes may have helped mitigate overdose harm.

Trends and correlates of discordant reporting of drug use among nightclub/festival attendees, 2019-2022

INTRODUCTION

People who attend nightclubs and festivals are known for high prevalence of party drug use, but more research is needed on underreporting in this population, in part because unintentional drug exposure through adulterated drug products is common. We examined the prevalence of drug use in this population, based both on self-reporting and on hair test results, with a focus on the detection of underreported use.

METHODS

Adults entering nightclubs and festivals in New York City were asked about past-year drug use in 2019-2022 (n = 1,953), with 328 providing an analyzable hair sample for testing. We compared trends in self-reported drug use, drug positivity, and "corrected" prevalence, adjusting for unreported use, and delineated correlates of testing positive for ketamine and cocaine after not reporting use (discordant reporting).

RESULTS

Of the 328 who provided a sample, cocaine and ketamine were the most frequently detected drugs (55.2% [n = 181] and 37.2% [n = 122], respectively), but these were also the two most underreported drugs, with 37.1% (n = 65) and 26.4% (n = 65), respectively, testing positive after not reporting use. Between 2019 and 2022, positivity decreased for cocaine, ketamine, 3,4-methylenedioxy-metamfetamine, and amfetamine, and underreported exposure to cocaine and ketamine also decreased (P < 0.05). Underreporting of the use of these drugs was common, but we also detected underreported exposure to ethylone, fentanyl, 3,4-methylenedioxyamfetamine, metamfetamine, and synthetic cannabinoids. Prevalence of discordant reporting of cocaine use was higher among those testing positive for ketamine exposure (adjusted prevalence ratio = 2.63; 95% CI: 1.48-4.69) and prevalence of discordant reporting of ketamine use was lower post-coronavirus disease caused by the SARS-CoV-2 virus (adjusted prevalence ratio = 0.39; 95% CI: 0.16-0.91) and among those reporting cocaine use (adjusted prevalence ratio = 0.53; 95% CI: 0.32-0.89).

DISCUSSION

Underreporting of drug use was common, suggesting the need for researchers to better deduce intentional underreporting versus unknown drug exposure via adulterants.

CONCLUSIONS

Researchers should consider both self-report and toxicology results from biological samples when examining trends in use.

Trajectories of drug treatment and illicit opioid use in the AIDS Linked to the IntraVenous Experience cohort, 2014-2019

BACKGROUND

Medication for opioid use disorder (MOUD) is an effective intervention to combat opioid use disorder and overdose, yet there is limited understanding of engagement in treatment over time in the community, contextualized by ongoing substance use. We aimed to identify concurrent trajectories of methadone prescriptions, buprenorphine prescriptions, and illicit opioid use among older adults with a history of injection drug use.

METHODS

We used data on 887 participants from the AIDS Linked to the IntraVenous Experience cohort, who were engaged in the study in 2013 and attended ≥1 visit during follow-up (2014-2019). Outcomes were self-reported MOUD prescription and illicit opioid use in the last 6 months. To identify concurrent trajectories in all 3 outcomes, we used group-based multi-trajectory modeling. We examined participant characteristics, including sociodemographics, HIV status, and other substance use, overall and by cluster.

RESULTS

We identified 4 trajectory clusters: (1) no MOUD and no illicit opioid use (43%); (2) buprenorphine and some illicit opioid use (11%); (3) methadone and no illicit opioid use (28%); and (4) some methadone and illicit opioid use (18%). While prevalence of each outcome was stable across time, transitions on/off treatment or on/off illicit opioid use occurred, with the rate of transition varying by cluster. The rate of transition was highest in Cluster 3 (0.74/person-year) and lowest in Cluster 1 (0.18/person-year). We saw differences in participant characteristics by cluster, including that the buprenorphine cluster had the highest proportion of people with HIV and participants who identified as non-Hispanic Black.

CONCLUSIONS

Most participants had discontinued illicit opioid use and were also not accessing MOUD. Trajectories defined by engagement with buprenorphine or methadone had distinct sociodemographic and behavioral characteristics, indicating that tailored interventions to expand access to both types of treatment are likely needed to reduce harms associated with untreated opioid use disorder.

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.

Changes in daily dose in open-label compared to double-blind: The role of clients' expectations in injectable opioid agonist treatment

Introduction

Though double-blind studies have indicated that hydromorphone and diacetylmorphine produce similar effects when administered through injectable opioid agonist treatment (iOAT) programs, participant preference may influence some aspects of medication dispensation such as dose.

Methods

 This is a retrospective longitudinal analysis. Participants (n = 131) were previously enrolled in a double-blind clinical trial for iOAT who continued to receive treatment in an open-label follow up study. Data included medication dispensation records from 2012 to 2020. Using linear regression and paired t-tests, average daily dose totals of hydromorphone and diacetylmorphine were examined comparatively between double-blind and open-label periods. A subgroup analysis explored dose difference by preference using the proxy, blinding guess, a variable used to facilitate the measurement of treatment masking during the clinical trial by asking which medication the participant thought they received.

Results

During the open-label period, participants prescribed diacetylmorphine received 49.5 mg less than during the double-blind period (95% CI -12.6,-86.4). Participants receiving hydromorphone did not see a significant dose decrease. Participants who guessed they received hydromorphone during the clinical trial, but learned they were on diacetylmorphine during the open-label period, saw a decrease in total daily dose of 78.3 mg less (95% CI -134.3,-22.4) during the open-label period.

Conclusion

If client preference is considered in the treatment of chronic opioid use disorder, clients may be able to better moderate their dose to suit their individual needs. Together with their healthcare providers, clients can participate in their treatment trajectories collaboratively to optimize client outcomes and promote person-centered treatment options.

Estimated Clinical Outcomes and Cost-effectiveness Associated With Provision of Addiction Treatment in US Primary Care Clinics

Importance

US primary care practitioners (PCPs) are the largest clinical workforce, but few provide addiction care. Primary care is a practical place to expand addiction services, including buprenorphine and harm reduction kits, yet the clinical outcomes and health care sector costs are unknown.

Objective

To estimate the long-term clinical outcomes, costs, and cost-effectiveness of integrated buprenorphine and harm reduction kits in primary care for people who inject opioids.

Design, Setting, and Participants

In this modeling study, the Reducing Infections Related to Drug Use Cost-Effectiveness (REDUCE) microsimulation model, which tracks serious injection-related infections, overdose, hospitalization, and death, was used to examine the following treatment strategies: (1) PCP services with external referral to addiction care (status quo), (2) PCP services plus onsite buprenorphine prescribing with referral to offsite harm reduction kits (BUP), and (3) PCP services plus onsite buprenorphine prescribing and harm reduction kits (BUP plus HR). Model inputs were derived from clinical trials and observational cohorts, and costs were discounted annually at 3%. The cost-effectiveness was evaluated over a lifetime from the modified health care sector perspective, and sensitivity analyses were performed to address uncertainty. Model simulation began January 1, 2021, and ran for the entire lifetime of the cohort.

Main Outcomes and Measures

Life-years (LYs), hospitalizations, mortality from sequelae (overdose, severe skin and soft tissue infections, and endocarditis), costs, and incremental cost-effectiveness ratios (ICERs).

Results

The simulated cohort included 2.25 million people and reflected the age and gender of US persons who inject opioids. Status quo resulted in 6.56 discounted LYs at a discounted cost of $203 500 per person (95% credible interval, $203 000-$222 000). Each strategy extended discounted life expectancy: BUP by 0.16 years and BUP plus HR by 0.17 years. Compared with status quo, BUP plus HR reduced sequelae-related mortality by 33%. The mean discounted lifetime cost per person of BUP and BUP plus HR were more than that of the status quo strategy. The dominating strategy was BUP plus HR. Compared with status quo, BUP plus HR was cost-effective (ICER, $34 400 per LY). During a 5-year time horizon, BUP plus HR cost an individual PCP practice approximately $13 000.

Conclusions and Relevance

This modeling study of integrated addiction service in primary care found improved clinical outcomes and modestly increased costs. The integration of addiction service into primary care practices should be a health care system priority.

Prevalence and factors associated with neck injection among people who inject drugs in San Francisco, California

BACKGROUND

Groin and neck injections are generally a last resort for people who inject drugs (PWID) who do not have easy access to functioning veins. These alternative injection practices can lead to an increased likelihood of adverse health outcomes. There is still much we do not know about groin and neck injections among PWID in the US, as the literature to-date comes from studies primarily focused on groin injections outside the US. We assessed prevalence, predictors, and associated behaviors of neck injection through a survey fielded in San Francisco, California, US.

METHODS

The sample comes from a longitudinal observational study that used targeted sampling to recruit PWID in San Francisco. The current study sample includes 239 PWID who completed their 12-month survey between June 2019 and June 2020.

RESULTS

About a third of the sample reported injecting in their neck in the past 30 days, with the most common reason being lack of available veins. Age, past 6-month abscess / soft tissue infection, and past 30-day use of opioids mixed with cocaine were significantly associated with past 30-day neck injection in the final multivariate model. Past 30-day neck injection was also significantly associated with being injected by another person in the past 30 days.

CONCLUSIONS

PWID at higher risk for vein deterioration were more likely to inject into their neck. Harm reduction strategies such as safer injection counseling, safe smoking supplies, use of "street doctors," and safe consumption sites may reduce instances of neck injection and/or associated health risks.

Characteristics and correlates of fentanyl preferences among people with opioid use disorder

OBJECTIVES

Fentanyl has come to dominate the U.S. illicit opioid supply. We aimed to characterize and examine correlates of preferences for fentanyl vs. other opioids among individuals starting OUD treatment.

METHODS

We interviewed 250 adults initiating buprenorphine treatment with positive fentanyl toxicology at intake. We characterized opioid preferences and examined bivariate associations between opioid preference (preference for heroin, fentanyl, heroin-fentanyl mix, or other opioid) and sociodemographic characteristics, psychosocial factors, and substance use behaviors. We then used multinomial logistic regression to examine factors independently associated with fentanyl preferences.

RESULTS

Over half (52.0 %) of participants preferred fentanyl (21.2 % fentanyl alone, 30.8 % heroin-fentanyl mix). In bivariate comparisons, participants who preferred fentanyl were a higher acuity group with respect to risks and problems in general. In the multinomial logistic regression, people who preferred fentanyl, either alone or mixed with heroin, used non-prescribed buprenorphine less in the 30 days preceding treatment entry compared to people who preferred heroin or other opioids (RRRalone= 0.88 [0.78, 0.99]; P = 0.037 and RRRmixed= 0.91 [0.84, 0.99]; P = 0.046). People who preferred fentanyl alone were also younger (RRR= 0.93 [0.90, 0.97]; P < 0.001) and more likely to have severe mental illness (RRR= 2.5 [1.1, 5.6]; P = 0.027) than people who prefer heroin or other opioids.

CONCLUSIONS

Many people with OUD report preferring fentanyl. People who express preference for fentanyl differ substantively from those with other opioid preferences, and may be at elevated risk for poor health outcomes. Understanding preferences surrounding fentanyl could inform treatment and harm reduction interventions.

A pilot study of a mixed-method approach to design an ED-based peer mHealth referral tool for HIV/HCV and opioid overdose prevention services

BACKGROUND

The intersecting epidemics of opioid misuse, injection drug use, and HIV/HCV have resulted in record overdose deaths and sustained high levels of HIV/HCV transmissions. Literature on social networks suggests opportunities to connect people who use drugs (PWUD) and their peers to HIV/HCV and opioid overdose prevention services. However, little evidence exists on how to design such peer referral interventions in emergency department (ED) settings.

METHODS

A mixed-method study was conducted to assess the feasibility of an mHealth-facilitated 'patient to peer social network referral program' for PWUD. In-depth interviews (IDIs) and quantitative surveys were conducted with urban ED patients (n = 15), along with 3 focus group discussions (FGDs) (n = 19).

RESULTS

Overall, 34 participants were enrolled (71 % males, 53 % Black). 13/15 IDI participants reported a history of opioid overdose; all had witnessed overdose events; all received HIV/HCV testing. From survey responses, most would invite their peers for HIV/HCV testing and naloxone training; and anticipated peers to accept referrals (HIV: 60 %, HCV: 73 %, naloxone: 93 %). Qualitative data showed PWUD shared health-related information with each other but preferred word of mouth rather than text messages. Participants used smartphones regularly and suggested using Internet advertising for prevention services. Participants expressed enthusiasm for ED-based peer mHealth referral platform to prevention services, as well as referring their peers to proposed services, with monetary incentives.

CONCLUSION

ED-based peer referral intervention to HIV/HCV testing and naloxone training was viewed favorably by PWUD. Frequent smartphone use among PWUD suggests that the medium could be a promising mode for peer referral.

Fentanyl preference among people who use opioids in New York City

BACKGROUND

Several studies have pointed to a sub-sample of people who use drugs (PWUD) who prefer the use of non-pharmaceutical fentanyl (NPF) and, as such, pose a unique challenge for public health initiatives amidst the continued rise in overdose mortality. However, matters of drug preference and autonomy of choice remain under-studied and often misunderstood. This paper examined the experiences of PWUD reporting a preference for NPF or an NPF-heroin mixture, specifically how they navigate the perceived benefits of NPF and its established risks.

METHODS

22 in-depth interviews were conducted in New York City between March 2018 and August 2019 with PWUD who self-reported a preference for NPF or an NPF-heroin mix. Interviews were audio-recorded, and the resulting transcripts analyzed using a thematic approach.

RESULTS

Participants highlighted various factors that contributed to expressed preference for NPF or an NPF-heroin mix, including a desire to feel good, financial resources, drug availability, decreased consumer autonomy, and physiological demand. Participants reported practicing several risk reduction strategies; however, they highlighted that many, particularly carrying naloxone and always using with someone else, were difficult to implement in the context of illicit drug use.

CONCLUSIONS

Our results demonstrate participants' decreased consumer agency and greater exposure to systemic factors in the illicit markets, highlighting the need for expansion of various services, including drug checking resources and systems of outreach for PWUD who do not use intravenously. To promote tailored interventions, continued efforts in overdose prevention ought to more thoughtfully consider the context, perceptions, preferences, and behaviors of PWUD.

Trends in characteristics of fentanyl-related poisonings in the United States, 2015-2021

Background: Fentanyl-related deaths continue to increase in the United States; however, most national studies focus on fatal overdose. More research, including data on nonfatal overdose, is needed.Objective: We examined trends in characteristics of fatal and nonfatal fentanyl-related poisonings ("exposures") in the US.Methods: National Poison Control data were examined to estimate trends in characteristics of reported exposures between 2015 and 2021 (N = 15,391; 38.7% female). We also delineated correlates of experiencing a major adverse effect or death.Results: The proportion of exposures increased among all age groups between ages 13 and 39 (ps < .05) with the largest increase among those age 13-19 (a 127.8% increase). With respect to reasons for use, the proportion of cases involving fentanyl "abuse" increased by 63.8% (p < .001). The proportion involving fentanyl inhalation increased 427.6% from 5.7% to 29.9% and injection increased from 6.7% to 9.6%, a 42.3% increase (ps < .01). The proportion also increased for co-use of methamphetamine (by 669.0%), cocaine (by 374.0%), and heroin (by 159.5%). The proportion of major adverse effects increased from 15.5% to 39.6% (p < .001). In the multivariable model, "abuse", suspected suicide attempts, and use via inhalation were risk factors for experiencing a major effect or death, and misuse, ingestion, dermal use, and co-use of methamphetamine were associated with lower risk.Conclusion: Poison Control data suggest that characteristics of individuals exposed to fentanyl continue to shift, with use via inhalation increasing and medical outcomes of nonfatal poisonings becoming more severe. These results complement mortality data and inform prevention and harm reduction efforts.

"It's probably going to save my life;" attitudes towards treatment among people incarcerated in the era of fentanyl

INTRODUCTION

In recent years, there has been a dramatic increase in overdose deaths involving illicitly manufactured fentanyl. The risk of death due to fentanyl exposure is far higher for people without adequate tolerance, such as those being released from incarceration. However, little is known about knowledge and perceptions of fentanyl among people who are incarcerated.

METHODS

We conducted 40 semi-structured qualitative interviews with people who were incarcerated at the Rhode Island Department of Corrections (RIDOC). We explored the impressions of, preferences for and experiences with fentanyl among these people. Analysis employed a general, inductive approach using NVivo 12.

RESULTS

We found that a majority of the participants were familiar with fentanyl, sought to avoid it and utilized harm reduction techniques when using drugs and taking treatment with medication for opioid use disorder (MOUD) to reduce their risk of overdose.

DISCUSSION

Our findings suggest that broad access to MOUD, especially for incarcerated people, is increasingly necessary in the era of fentanyl, both to aid people seeking recovery due to the increased overdose risk of drug use and to reduce overdose morbidity for people who use drugs.

Mortality among people who inject drugs: a prospective cohort followed over three decades in Baltimore, MD, USA

BACKGROUND AND AIMS

During the past decades, people who inject drugs (PWID) have been impacted by the development of combination antiretroviral therapy (cART) to combat HIV/AIDS, the prescription opioid crisis and increased use of lethal synthetic opioids. We measured how these dynamics have impacted mortality among PWID in an urban US city.

DESIGN

Prospective cohort study using data from the AIDS Linked to the Intravenous Experience (ALIVE).

SETTING

Baltimore, MD, USA from 1988 to 2018.

PARTICIPANTS

A total of 5506 adult PWIDs (median age at baseline 37 years).

MEASUREMENTS

Mortality was identified by linkage to National Death Index-Plus (NDI-Plus) and categorized into HIV/infectious disease (HIV/ID) deaths, overdose and violence-related (drug-related) deaths and chronic disease deaths. Person-time at risk accrued from baseline and ended at the earliest of death or study period. All-cause and cause-specific mortality were calculated annually. The Fine & Gray method was used to estimate the subdistribution hazards of cause-specific deaths accounting for competing risks.

FINDINGS

Among 5506 participants with 84 226 person-years of follow-up, 43.9% were deceased by 2018. Among all deaths, 30.5% were HIV/ID deaths, 24.4% drug-related deaths and 33.3% chronic disease deaths. Age-standardized all-cause mortality increased from 23 to 45 per 1000 person-years from 1988 to 1996, declined from 1996 to 2014, then trended upward to 2018. HIV/ID deaths peaked in 1996 coincident with the availability of cART, then continuously declined. Chronic disease deaths increased continuously as the cohort aged. Drug-related deaths declined until 2011, but increased more than fourfold by 2018. HIV/HCV infection and active injecting were independently associated with HIV/ID and drug-related deaths. Female and black participants had a higher risk of dying from HIV/ID deaths and a lower risk of dying from drug-related deaths than male and non-black participants.

CONCLUSIONS

Deaths in Baltimore, MD, USA attributable to HIV/ID appear to have declined following the widespread use of combination antiretroviral therapy. Increases in the rates of drug-related deaths in Baltimore were observed prior to and continue in conjunction with national mortality rates associated with the opiate crisis.

Simulated Cost-effectiveness and Long-term Clinical Outcomes of Addiction Care and Antibiotic Therapy Strategies for Patients With Injection Drug Use-Associated Infective Endocarditis

IMPORTANCE

Emerging evidence supports the use of outpatient parenteral antimicrobial therapy (OPAT) and, in many cases, partial oral antibiotic therapy for the treatment of injection drug use-associated infective endocarditis (IDU-IE); however, long-term outcomes and cost-effectiveness remain unknown.

OBJECTIVE

To compare the added value of inpatient addiction care services and the cost-effectiveness and clinical outcomes of alternative antibiotic treatment strategies for patients with IDU-IE.

DESIGN, SETTING, AND PARTICIPANTS

This decision analytical modeling study used a validated microsimulation model to compare antibiotic treatment strategies for patients with IDU-IE. Model inputs were derived from clinical trials and observational cohort studies. The model included all patients with injection opioid drug use (N = 5 million) in the US who were eligible to receive OPAT either in the home or at a postacute care facility. Costs were annually discounted at 3%. Cost-effectiveness was evaluated from a health care sector perspective over a lifetime starting in 2020. Probabilistic sensitivity, scenario, and threshold analyses were performed to address uncertainty.

INTERVENTIONS

The model simulated 4 treatment strategies: (1) 4 to 6 weeks of inpatient intravenous (IV) antibiotic therapy along with opioid detoxification (usual care strategy), (2) 4 to 6 weeks of inpatient IV antibiotic therapy along with inpatient addiction care services that offered medication for opioid use disorder (usual care/addiction care strategy), (3) 3 weeks of inpatient IV antibiotic therapy along with addiction care services followed by OPAT (OPAT strategy), and (4) 3 weeks of inpatient IV antibiotic therapy along with addiction care services followed by partial oral antibiotic therapy (partial oral antibiotic strategy).

MAIN OUTCOMES AND MEASURES

Mean percentage of patients completing treatment for IDU-IE, deaths associated with IDU-IE, life expectancy (measured in life-years [LYs]), mean cost per person, and incremental cost-effectiveness ratios (ICERs).

RESULTS

All modeled scenarios were initialized with 5 million individuals (mean age, 42 years; range, 18-64 years; 70% male) who had a history of injection opioid drug use. The usual care strategy resulted in 18.63 LYs at a cost of $416 570 per person, with 77.6% of hospitalized patients completing treatment. Life expectancy was extended by each alternative strategy. The partial oral antibiotic strategy yielded the highest treatment completion rate (80.3%) compared with the OPAT strategy (78.8%) and the usual care/addiction care strategy (77.6%). The OPAT strategy was the least expensive at $412 150 per person. Compared with the OPAT strategy, the partial oral antibiotic strategy had an ICER of $163 370 per LY. Increasing IDU-IE treatment uptake and decreasing treatment discontinuation made the partial oral antibiotic strategy more cost-effective compared with the OPAT strategy. When assuming that all patients with IDU-IE were eligible to receive partial oral antibiotic therapy, the strategy was cost-saving and resulted in 0.0247 additional discounted LYs. When treatment discontinuation was decreased from 3.30% to 2.65% per week, the partial oral antibiotic strategy was cost-effective compared with OPAT at the $100 000 per LY threshold.

CONCLUSIONS AND RELEVANCE

In this decision analytical modeling study, incorporation of OPAT or partial oral antibiotic approaches along with addiction care services for the treatment of patients with IDU-IE was associated with increases in the number of people completing treatment, decreases in mortality, and savings in cost compared with the usual care strategy of providing inpatient IV antibiotic therapy alone.

Investigating opioid preference to inform safe supply services: A cross sectional study

BACKGROUND

The drug toxicity crisis continues to be a significant cause of death. Over 24,600 people died from opioid toxicity in Canada over the last 5 years. Safe supply programs are required now more than ever to address the high rate of drug toxicity overdose deaths caused by illicit fentanyl and its analogues. This study aims to identify opioid preferences and associated variables to inform further phases of safe supply program implementation.

METHODS

The Harm Reduction Client Survey, an annual cross-sectional survey of people who use drugs (PWUD), was administered at harm reduction supply distribution sites in BC in October-December 2019. The survey collects information on substance use patterns, associated harms, stigma, and utilization of harm reduction services. Eligibility criteria for survey participation included aged 19 years or older; self-reported substance use of any illicit substance in the past six months, and ability to provide verbal informed consent. We conducted multivariate logistic regression to investigate associations with opioid preference. We used the dichotomized preference for either heroin or fentanyl as an outcome variable. Explanatory variables of interest included: geographic region, urbanicity, gender, age category, Indigenous identity, housing, employment, witnessing or experiencing an overdose, using drugs alone, using drugs at an observed consumption site, injection as preferred mode of use, injecting any drug, frequency of use, and drugs used in last 3 days.

RESULTS

Of the 621 survey participants, 405 reported a preferred opioid; of these 57.8% preferred heroin, 32.8% preferred fentanyl and 9.4% preferred prescription opioids. The proportion of participants who preferred heroin over fentanyl significantly increased with age. The adjusted odds of a participant 50 or older preferring heroin was 6.76 (95% CI: 2.78-16.41, p-value: < 0.01) times the odds of an individual 29 or under. The adjusted odds of an Indigenous participant reporting a preference for heroin compared to fentanyl was 1.75 (95% CI: 1.03-2.98, p-value: 0.04) the odds of a non-Indigenous participant reporting the same. Adjusted odds of heroin preference also differed between geographic regions within British Columbia, Canada.

CONCLUSION

Opioid preference differs by age, geographic area, and Indigenous identity. To create effective safe supply programs, we need to engage PWUD about their drugs of choice.

Long-term Infective Endocarditis Mortality Associated With Injection Opioid Use in the United States: A Modeling Study

BACKGROUND

The expansion of the US opioid epidemic has led to significant increases in infections, such as infective endocarditis (IE), which is tied to injection behaviors. We aimed to estimate the population-level IE mortality rate among people who inject opioids and compare the risk of IE death against the risks of death from other causes.

METHODS

We developed a microsimulation model of the natural history of injection opioid use. We defined injection behavior profiles by both injection frequency and injection techniques. We accounted for competing risks of death and populated the model with primary and published data. We modeled cohorts of 1 million individuals with different injection behavior profiles until age 60 years. We combined model-generated estimates with published data to project the total expected number of IE deaths in the United States by 2030.

RESULTS

The probabilities of death from IE by age 60 years for 20-, 30-, and 40-year-old men with high-frequency use with higher infection risk techniques compared to lower risk techniques for IE were 53.8% versus 3.7%, 51.4% versus 3.1%, and 44.5% versus 2.2%, respectively. The predicted population-level attributable fraction of 10-year mortality from IE among all risk groups was 20%. We estimated that approximately 257 800 people are expected to die from IE by 2030.

CONCLUSIONS

The expected burden of IE among people who inject opioids in the United States is large. Adopting a harm reduction approach, including through expansion of syringe service programs, to address injection behaviors could have a major impact on decreasing the mortality rate associated with the opioid epidemic.

Detecting risk level in individuals misusing fentanyl utilizing posts from an online community on Reddit

INTRODUCTION

Opioid misuse is a public health crisis in the US, and misuse of synthetic opioids such as fentanyl have driven the most recent waves of opioid-related deaths. Because those who misuse fentanyl are often a hidden and high-risk group, innovative methods for identifying individuals at risk for fentanyl misuse are needed. Machine learning has been used in the past to investigate discussions surrounding substance use on Reddit, and this study leverages similar techniques to identify risky content from discussions of fentanyl on this platform.

METHODS

A codebook was developed by clinical domain experts with 12 categories indicative of fentanyl misuse risk, and this was used to manually label 391 Reddit posts and comments. Using this data, we built machine learning classification models to identify fentanyl risk.

RESULTS

Our machine learning risk model was able to detect posts or comments labeled as risky by our clinical experts with 76% accuracy and 76% sensitivity. Furthermore, we provide a vocabulary of community-specific, colloquial words for fentanyl and its analogues.

DISCUSSION

This study uses an interdisciplinary approach leveraging machine learning techniques and clinical domain expertise to automatically detect risky discourse, which may elicit and benefit from timely intervention. Moreover, our vocabulary of online terms for fentanyl and its analogues expands our understanding of online "street" nomenclature for opiates. Through an improved understanding of substance misuse risk factors, these findings allow for identification of risk concepts among those misusing fentanyl to inform outreach and intervention strategies tailored to this at-risk group.

Characteristics of adults reporting illicitly manufactured fentanyl or heroin use or prescription opioid misuse in the United States, 2019

BACKGROUND

Deaths involving illicitly manufactured fentanyl (IMF) have increased since 2013 in the United States. Little research has examined individuals using IMF. This study aims to explore the characteristics of US adults who used IMF, heroin, or misused prescription opioids and examine the associations between demographic, clinical, psychosocial characteristics and IMF use.

METHODS

A convenience sample of adults aged ≥ 18 years being assessed for substance use disorder (SUD) treatment was collected between January-December 2019 using the Addiction Severity Index-Multimedia Version instrument. We used a multivariable logistic regression model to examine the associations between demographic, clinical, psychosocial characteristics and IMF use.

RESULTS

Adults reporting IMF as their primary lifetime substance use problem also reported using other substances-most often alcohol or heroin-both in the past 30 days and during their lifetime. Characteristics associated with increased odds of reporting IMF as the primary lifetime substance use problem included age 18-24 years (adjusted odds ratio (aOR) = 1.68; 95% confidence interval (CI) = 1.18-2.38) versus 45-54 years, non-Hispanic Black persons (aOR = 1.44; 95% CI = 1.11-1.85) versus non-Hispanic White persons, being assessed in Northeast (aOR = 15.46; 95% CI = 8.67-27.56) versus West, and having a history of at least one lifetime overdose (1 overdose (aOR = 1.91; 95% CI = 1.49-2.44); 2 overdoses (aOR = 1.95; 95% CI = 1.48-2.58); 3 or more overdoses (aOR = 2.27; 95% CI = 1.82-2.82)).

CONCLUSIONS

These findings provide new insights into this high-risk population and help identify strategies to address increasing overdose death rates involving IMF. Opportunities for intervention include expanding naloxone distribution and harm reduction programs and connecting individuals with nonfatal overdoses to SUD treatment.

Transition from injecting opioids to smoking fentanyl in San Francisco, California

BACKGROUND

The introduction of illicitly made fentanyl in the United States has slowly replaced heroin. New illicit drugs are often associated with changes in frequency and modes of administration. We assessed changes in injection frequency and smoking fentanyl in the new era of fentanyl availability in San Francisco.

METHODS

We used targeted sampling to recruit 395 people who inject drugs (PWID) into an observational cohort study in San Francisco 2018-2020. We assessed changes in injection frequency, opioid injection frequency and fentanyl smoking frequency in four six-month periods. We also conducted qualitative interviews with PWID asking about motivations for injecting and smoking opioids.

RESULTS

The median number of past-month injections steadily decreased by semi-annual calendar year from 92 injections in July to December 2018 to 17 injections in January to June 2020. The rate of opioid injections reduced by half (Adjusted Incidence Rate Ratio = 0.41; 95 % Confidence Interval = 0.25, 0.70; p < 0.01). The number of days smoking fentanyl was associated with fewer number of injections (X2(2) = 11.0; p < 0.01). Qualitative interviews revealed that PWID's motivation for switching from injecting tar heroin to smoking fentanyl was related to difficulties accessing veins. After switching to smoking fentanyl, they noticed many benefits including how the drug felt, improved health, fewer financial constraints, and reduced stigma.

CONCLUSION

Between 2018 and 2020, there was a shift from injecting tar heroin to smoking fentanyl in San Francisco. Reductions in injection of illicit drugs may offer public health benefit if it reduces risk of blood-borne viruses, abscesses and soft-tissue infections, and infective endocarditis.

Predictors of intentional fentanyl use: Market availability vs consumer demand

BACKGROUND

Attempts to reduce opioid overdoses have been complicated by the dramatic rise in fentanyl use. While market forces contributing to fentanyl proliferation in the illicit drug supply have increased inadvertent exposure to the drug, rising fentanyl use may also be driven by growing consumer demand. Interventions to reduce the spread of fentanyl must be based on an understanding of the motivations underlying its use.

METHODS

Data for this cross-sectional study were derived from a computerized self-administered survey completed by a convenience sample of 432 people who use illicit opioids (PWUO) recruited from methadone and detoxification programs in NJ. The anonymous survey was based on a prior qualitative study of attitudes and behaviors surrounding opioid use. Multivariate analysis identified correlates of intentional fentanyl use in the full sample and among sub-populations of white and non-white PWUO.

RESULTS

In the full sample, intentional fentanyl use was associated with white race/ethnicity, younger age, polydrug use, and a preference for the drug effects of fentanyl, which more than tripled the probability of intentional use (AOR=3.02; 95% CI=1.86-4.89; p=.000). Among whites, a preference for the fentanyl drug effects was also the strongest predictor of intentional use (AOR=5.34; 95% CI=2.78-10.28; p=.000). Among non-whites, however, exposure, not preference, was the primary driver of use, with intentional use more than doubling (AOR=2.48; 95% CI=1.04-5.91; p<.05) among those living in high fentanyl dispersion counties.

CONCLUSION

The motivations underlying fentanyl use are multifactorial and vary across populations of PWUO, indicating a need for targeted interventions to counter the increasing spread and adverse consequences of fentanyl use. In order to counteract the increasing spread and adverse consequences of fentanyl use, these findings indicate a need for harm-reduction interventions, like drug testing or supervised injection sites, that address the differing motivations for fentanyl use among PWUO.

Purposeful Fentanyl Use and Associated Factors among Opioid-Dependent People Who Inject Drugs

Introduction: In recent years, opioid-related mortality has increased steadily in the United States. Fentanyl, a synthetic opioid, has been a primary driver of the current wave of overdose-related deaths. Little is known, however, about fentanyl use among opioid-dependent people who inject drugs (PWID). We, therefore, sought to characterize purposeful fentanyl use among PWID. Methods: A cross-sectional survey was administrated to 104 opioid-dependent PWID on methadone who self-reported drug- or sex-related risk behaviors. Participants were recruited between July 2018 and October 2019 from a methadone clinic in New Haven, Connecticut. Multivariable logistic regressions were used to identify independent correlates of purposeful fentanyl use. Results: Overall, 43.2% and 22.1% of the participants reported any (lifetime) or recent (past 30 days) purposeful fentanyl use, respectively. Independent correlates of any purposeful fentanyl use were younger age (aOR= 0.94; p = 0.021), recent daily injection (aOR= 3.52; p = 0.047), recent cocaine use (aOR= 3.54; p = 0.041), and moderate/severe depression (aOR= 3.82; p = 0.028). Independent correlates of recent purposeful fentanyl use were moderate/severe depression (aOR= 10.94; p = 0.031), recently sharing injection equipment (aOR= 2.96; p = 0.044), and recently engaging in transactional sex (aOR= 3.60; p = 0.026). Conclusions: These findings indicate that opioid-dependent PWID on methadone remain at increased risk for overdose given the high prevalence of ongoing purposeful fentanyl exposure. Interventions to reduce the harms associated with fentanyl use should target young PWID and active fentanyl users, with an emphasis on achieving adequate methadone dosage and screening and treating depression in methadone-maintained patients who preferentially seek fentanyl.

Epidemiological serosurvey and molecular characterization of sexually transmitted infections among 1890 sheltered homeless people in Marseille: Cross-sectional one day-surveys (2000-2015)

OBJECTIVES

We observed the prevalence and distribution of potential risk factors for sexually transmitted infections (STIs) among Marseille homeless population.

METHODS

Over the 2000-2015 period, we enrolled 1890 sheltered homeless adults and collected serum samples. Markers of hepatitis B and C viruses (HBV, HCV) and Treponema pallidum were searched using the CMIA testing. Positive HBsAg or anti-HCV samples underwent sequencing; positive anti-T. pallidum sera were subjected to the RPR test.

RESULTS

The overall prevalence of HBsAg, anti-HBs, anti-HBc, anti-HCV and anti-T. pallidum (by CMIA and RPR) was 4.1%, 22.9%, 35.5%, 5.3% and (6.8%, 1.0%), respectively. We found a significantly higher prevalence of HBsAg and anti-T. pallidum among individuals born in sub-Saharan Africa (or Asia) compared to those born in Europe. Being older (>42 years), toxicomania status, cannabis use and underweight status (compared to normal status) were independent factors associated with HCV seropositivity. Using sequencing, we obtained a substantial diversity of HBV and HCV genotypes. One HCV sequence harbouring a L31M substitution in the NS5a protein may be associated with reduced drug sensitivity.

CONCLUSIONS

The positive relationship between toxicomania and HCV suggests the need for effective prevention programmes including health education activities and addiction treatment.

Agency in the fentanyl era: Exploring the utility of fentanyl test strips in an opaque drug market

BACKGROUND

In Baltimore, the emergence of fentanyl and its analogues exacerbated an existing heroin crisis and increased uncertainty about drug composition and potency. In an effort to reduce overdoses, harm reduction organizations and health departments across the U.S. began distributing fentanyl test strips, a low barrier, inexpensive drug checking strategy. Studies show that people who use drugs (PWUD) frequently suspect that their drugs contain fentanyl and are interested in using fentanyl test strips to check their drugs; however, some people question their usefulness in regions where fentanyl presence is assumed. Understanding the utility of fentanyl test strips in fentanyl-saturated markets is a priority to best tailor interventions.

METHODS

In-depth interviews (N = 20) were conducted with individuals who reported recent (past 30 days) opioid use in Baltimore, MD.

RESULTS

Fentanyl was viewed as pervasive, dangerous, and difficult to avoid in the local drug supply. This dominant narrative characterized PWUD as disempowered by the heightened unpredictability of the drug market. While several strategies are used to navigate the drug market, respondents wanted more information about their drugs. In this context, fentanyl test strips were used in unique and unexpected ways to empower PWUD to be savvier market consumers, including avoiding fentanyl when there could be negative social or legal consequences, negotiating with dealers, and helping others in their social network navigate the opaque drug market.

CONCLUSION

These findings add nuance and place fentanyl preference and use in the context of the drug market. When fentanyl presence is assumed, people used fentanyl test strips in unexpected ways to gain some control over their drug use. Novel uses for fentanyl test strips strengthen existing strategies used to navigate the drug market and mitigate overdose risk, and highlight their potential to quickly disseminate valuable information about the local drug supply.

Preclinical Evaluation of Vaccines to Treat Opioid Use Disorders: How Close are We to a Clinically Viable Therapeutic?

The ongoing opioid crisis, now into its second decade, represents a global public health challenge. Moreover, the opioid crisis has manifested despite clinical access to three approved opioid use disorder medications: the full opioid agonist methadone, the partial opioid agonist buprenorphine, and the opioid antagonist naltrexone. Although current opioid use disorder medications are underutilized, the ongoing opioid crisis has also identified the need for basic research to develop both safer and more effective opioid use disorder medications. Emerging preclinical evidence suggests that opioid-targeted vaccines or immunopharmacotherapies may be promising opioid use disorder therapeutics. One premise for this article is to critically examine whether vaccine effectiveness evaluated using preclinical antinociceptive endpoints is predictive of vaccine effectiveness on abuse-related endpoints such as drug self-administration, drug discrimination, and conditioned place preference. A second premise is to apply decades of knowledge in the preclinical evaluation of candidate small-molecule therapeutics for opioid use disorder to the preclinical evaluation of candidate opioid use disorder immunopharmacotherapies. We conclude with preclinical experimental design attributes to enhance preclinical-to-clinical translatability and potential future directions for immunopharmacotherapies to address the dynamic illicit opioid environment.