Drug checking in the fentanyl era: Utilization and interest among people who inject drugs in San Diego, California

Changes in injecting versus smoking heroin, fentanyl, and methamphetamine among people who inject drugs in San Diego, California, 2020-2023

BACKGROUND

Amidst an increasingly toxic drug supply in North America, people who inject drugs may be transitioning to smoking them. We aimed to assess changes in injecting and smoking opioids and methamphetamine among a cohort of people who inject drugs from San Diego, California.

METHODS

Over five six-month periods spanning October 2020-April 2023, we assessed prevalence of injecting and smoking opioids or methamphetamine and whether participants used these drugs more frequently by smoking than injecting. Multivariable Poisson regression via generalized estimating equations was used to examine time trends.

RESULTS

Of 362 participants, median age was 40 years; a minority were female (29%), Hispanic/Latinx/Mexican (45%), and housed (33%). Among this cohort, of whom 100% injected (and 84% injected and smoked) in period one (October 2020-April 2021), by period five (November 2022-April 2023), 34% only smoked, 59% injected and smoked, and 7% only injected. By period five, the adjusted relative risk (aRR) of injecting opioids was 0.41 (95% Confidence Interval [CI]: 0.33, 0.51) and the aRR for injecting methamphetamine was 0.50 (95% CI: 0.39, 0.63) compared to period one. Risks for smoking fentanyl rose significantly during period three (aRR=1.44, 95% CI: 1.06, 1.94), four (aRR=1.65, 95% CI: 1.24, 2.20) and five (aRR=1.90, 95% CI: 1.43, 2.53) compared to period one. Risks for smoking heroin and methamphetamine more frequently than injecting these drugs increased across all periods.

CONCLUSIONS

Opioid and methamphetamine injection declined precipitously, with notable increases in smoking these drugs. Research is needed to understand the health consequences of these trends.

HIV-1 transmission dynamics among people who inject drugs on the US/Mexico border during the COVID-19 pandemic: a prosepective cohort study

Background

We examined HIV prevalence and transmission dynamics among people who inject drugs in the U.S./Mexico border region during the COVID-19 pandemic.

Methods

People who inject drugs aged ≥18 years from 3 groups were recruited: people who inject drugs who live in San Diego (SD) and engaged in cross-border drug use in Tijuana, Mexico (SD CBDUs), and people who inject drugs in SD and Tijuana (TJ) who did not engage in cross-border drug use (NCBDUs). We computed HIV prevalence at baseline and bivariate incidence-density rates (IR) at 18-month follow-up. Bayesian phylogenetic analysis was used to identify local transmission clusters, estimate their age, and effective reproductive number (Re) over time within the clusters.

Findings

At baseline (n = 612), 26% of participants were female, 9% engaged in sex work, and HIV prevalence was 8% (4% SD CBDU, 4% SD NCBDU, 16% TJ NCBDU). Nine HIV seroconversions occurred over 18 months, IR: 1.357 per 100 person-years (95% CI: 0.470, 2.243); 7 in TJ NCBDU and 2 in SD CBDU. Out of 16 identified phylogenetic clusters, 9 (56%) had sequences from both the U.S. and Mexico (mixed-country). The age of three youngest mixed-country dyads (2018-2021) overlapped with the COVID-related US-Mexico border closure in 2020. One large mixed-country cluster (N = 15) continued to grow during the border closure (Re = 4.8, 95% Highest Posterior Density (HPD) 1.5-9.1) with 47% engaging in sex work.

Interpretation

Amidst the COVID-19 pandemic and the border closure, cross-border HIV clusters grew. Efforts to end the HIV epidemic in the U.S. should take into account cross-border HIV-1 transmission from Tijuana. Mobile harm reduction services and coordination with municipal HIV programs to initiate anti-retroviral therapy and pre-exposure prophylaxisis are needed to reduce transmission.

Funding

This research was supported by the James B. Pendleton Charitable Trust and the San Diego Center for AIDS Research.

Changes in injecting versus smoking heroin, fentanyl, and methamphetamine among people who inject drugs in San Diego, California, 2020 to 2023

Background

Amidst a rapidly evolving drug supply in North America, people who inject drugs may be transitioning to smoking them. We aimed to assess changes in injecting and smoking heroin, fentanyl and methamphetamine among a cohort of people who injected drugs at baseline from San Diego, California.

Methods

Over five six-month periods spanning October 2020-April 2023, we assessed prevalence of injecting and smoking opioids or methamphetamine and whether participants used these drugs more frequently by smoking than injecting. Multivariable Poisson regression via Generalized Estimating Equations was used to examine time trends.

Results

Of 362 participants, median age was 40 years; most were male (72%), non-Hispanic (55%), and unhoused (67%). Among this cohort, of whom 100% injected (or injected and smoked) at baseline, by period five (two years later), 34% reported only smoking, while 59% injected and smoked, and 7% only injected. By period five, the adjusted relative risk (aRR) of injecting opioids was 0.41 (95% Confidence Interval [CI]: 0.33, 0.51) compared to period one, and the aRR for injecting methamphetamine was 0.50 (95% CI: 0.39, 0.63). Compared to period one, risks for smoking fentanyl rose significantly during period three (aRR=1.44, 95% CI: 1.06, 1.94), four (aRR=1.65, 95% CI: 1.24, 2.20) and five (aRR=1.90, 95% CI: 1.43, 2.53). Risks for smoking heroin and methamphetamine more frequently than injecting these drugs increased across all periods.

Conclusions

Opioid and methamphetamine injection declined precipitously, with notable increases in smoking these drugs. Research is urgently needed to understand the health consequences of these trends.

Fentanyl Exposure and Detection Strategies Utilized by Clinical Trial Participants Seeking Linkage to Opioid Use Disorder Treatment at a Syringe Service Program

INTRODUCTION

The USA continues to face a fentanyl-driven overdose epidemic. Prior research has demonstrated users of illicit opioids are concerned about fentanyl exposure and overdose, but the strategies they report using to detect fentanyl's presence lack empirical support. This study compares self-report and biologically detected fentanyl use and investigates overdose risk and risk reduction behaviors among a sample of high-risk people who use opioids.

METHODS

Structured enrollment interviews conducted as part of a larger clinical trial assessed self-reported fentanyl exposure as well as strategies used to determine believed fentanyl exposure and prevent overdose among 240 participants enrolled at a Chicago, IL syringe service program. Urinalysis measured actual fentanyl exposure.

RESULTS

Most participants identified as African American (66.7%) and had considerable overdose experience (76.7% lifetime and 48% in the past year). Most also tested positive for fentanyl (93.75%) despite reporting no past year use of fentanyl or fentanyl-adulterated drugs (64.17%). The most utilized approaches reported for identifying fentanyl exposure were stronger effects of the drug (60.7%), sight or taste (46.9%), and being told by someone using the same drugs (34.2%). Few participants (14%) reported using fentanyl test strips. No significant associations were identified between self-report and urinalysis measures or urinalysis results and risk reduction strategies.

CONCLUSION

This study adds to prior fentanyl exposure risk research. The disconnect between participants' fentanyl detection methods and reported overdose experiences supports the need for more research to identify and understand factors driving access and use of overdose prevention resources and strategies.

Motivators of and barriers to drug checking engagement in British Columbia, Canada: Findings from a cross-sectional study

OBJECTIVE

Responding to increasing rates of illicit drug toxicity mortality in British Columbia, regional health authorities introduced various types and models of drug checking services starting in 2016. Uptake has been gradual yet consistent, but motivators and barriers of service use have not been well-described.

METHODS

The British Columbia Harm Reduction Client Survey is a cross-sectional survey conducted at harm reduction sites across British Columbia. Data for the present findings were collected between March 2021 and January 2022. Participants (n = 537) were asked about their use of drug checking services and what prevented them from using available services. Responses were analyzed with descriptive statistics and multivariable logistic regression.

RESULTS

Of all participants, 519 (96.6 %) answered the survey question on drug checking with 144 (27.7 %) reporting having used services within six months. Participants highlighted barriers such as not knowing where to access services (21.0 %), or not having services in their area (10.0 %). Among people who did not report recent use of fentanyl, 49.6 % stated they would not use their drugs if they tested positive for fentanyl. Other harm reduction behaviors were positively associated with drug checking, such as use of overdose prevention sites (adjusted odds ratio [AOR]: 2.75, 95 % confidence interval [CI]: 1.65, 4.59) and having a naloxone kit (AOR: 2.67, 95 %CI: 1.14, 6.28). Receipt of opioid agonist therapy in the previous six months was also positively associated with drug checking (AOR: 1.72, 95 %CI: 1.05, 2.83).

DISCUSSION

Drug checking uptake remains low in British Columbia, however this study identified desire for services among participants, suggesting a need for expanded drug checking services. Behavioral change was reported among a high proportion of people who said they would not use their drugs if they tested positive for fentanyl, meaning that immunoassay strips alone have utility in the context of a pervasive fentanyl supply.

A survey of North American drug checking services operating in 2022

BACKGROUND

Drug overdose deaths have reached record-breaking levels in North America. Drug checking services (DCS) provide localized information on the contents of drugs to individuals and communities. Depending on the design, individuals can submit drug samples for onsite "real-time" testing or offsite testing. The results can shed light on emerging drugs in the community and support ongoing prevention and surveillance efforts. We sought to describe and report aggregate outcomes of DCS operating in North America.

METHODS

The North American Drug Checking Survey was launched in 2022 to characterize and monitor DCS operating in the region. Sixteen organizations from the US (n = 9), Canada (n = 5), and Mexico (n = 2) responded to the survey. Each organization reported on their program's operations and provided service delivery outcomes (site- or program-level) in the aggregate.

RESULTS

Participating organizations reported testing a total of 49,786 drug samples between 2014 and 2022. DCS were run by community-led organizations (44%), health departments (25%), universities (19%), or clinical/private laboratories (19%). The types of samples tested differed between programs (e.g., solids vs. liquids, drug paraphernalia accepted). While most organizations tested onsite using fentanyl test strips (88%) and Fourier-transform infrared (FTIR) spectroscopy (63%), many sent samples offsite for confirmatory testing (63%), most often with mass spectrometry. Common facilitators of operating a DCS included: interest of clients (69%), interest of service providers (63%), and receiving external technical assistance (63%). Barriers included: the lack of funding (81%) or staff (50%), gaps in technical expertise (38%), as well as laws banning the possession and/or distribution of illicit drug samples, drug paraphernalia, or drug checking equipment (38%).

CONCLUSION

DCS are scaling up in North America. Given the evolving and localized nature of illicit drug supplies, supporting the establishment and operations of DCS could enhance the public's understanding of local drug supplies to reduce drug-related harms over time.