Estimating the size of crack cocaine users in France: Methods for an elusive population with high heterogeneity

Correlates of Stimulant Use among People Who Use Heroin Undergoing Treatment in Out-Patient Facilities in France, 2010-2020

Background: Polydrug use has been implicated in driving a "fourth wave" of the overdose crisis in North America, specifically through concurrent use of stimulants and opioids, especially fentanyl. In France, however, heroin has historically been and remains the easiest-to-access opioid, accounting for most drug treatment demand. Whether similar polydrug use is increasing in Western Europe remains understudied, despite severe health implications and potential inadequate public health responses.Methods: We take advantage of a nation-wide dataset containing information on all patients serviced in treatment centers in France from 2010 to 2020. We conduct Poisson regression to determine the main predictors of stimulant use among people who use heroin (PWUH) and opioids (PWUO) generally.Results: Heroin remains the primary opioid within drug treatment in France. A decreasing number of out-patients seeking treatment for heroin use has been accompanied by an increasing trend of stimulant use over time, most commonly with powder cocaine. Our results suggest a significant increase of crack cocaine use among the most vulnerable PWUH. Concurrent use of stimulants among PWUH was positively associated with use of alcohol, cannabis, unprescribed psychotropics and hallucinogens, and negatively with tobacco. Similar results were found for all in-treatment PWUO.Conclusions: Our results uncover heterogeneity in the profiles of PWUH that should be fully acknowledged to ensure better efficiency in substance use clinical practices and policy, while simultaneously drawing attention to trends in concurrent opioid-stimulant use outside North America. We advocate for an extension of the generalized risk framework and its implementation in prevention programs.

Recent increases in crack injection and associated risk factors among people who inject psychoactive drugs in England and Wales

BACKGROUND

Crack use is higher in the United Kingdom (UK) than other European countries. Crack is a stimulant with a short half-life, requiring frequent injection to maintain its euphoric effects, thus increasing the risk of blood borne viruses (BBVs) and skin and soft tissue infections (SSTIs). We assessed trends in the prevalence of current crack injection among people who inject drugs (PWID) and investigated harms and other factors associated with its use.

METHODS

We used data from the annual Unlinked Anonymous Monitoring Survey of PWID, which recruits people who have ever injected psychoactive drugs through specialist services. Participants provide a biological sample and self-complete a questionnaire. We included participants from England and Wales who had injected in the past month. We examined trends in crack injection over time (2011-2021) and factors associated with crack injection using multivariable logistic regression (2019-2021).

RESULTS

The proportion of people self-reporting crack injection in the past month almost doubled between 2011-2020/21, from 34 % (416/1237) to 57 % (483/850). Crack injection was more frequently reported by males than females (adjusted odds ratio 1.46, 95 % confidence interval: 1.15-1.87) and injected alongside heroin (6.67, 4.06-10.97) more frequently than alone. Crack injection was independently associated with injecting equipment sharing (1.64, 1.30-2.07), groin injection (2.03, 1.60-2.56) in the past month, overdosing in the past year (1.90, 1.42-2.53), homelessness in the past year (1.42, 1.14-1.77) and ever having hepatitis C infection (1.64, 1.31-2.06).

CONCLUSION

Crack injection has increased significantly over the past decade in England and Wales. People injecting crack are more likely to engage in behaviours that increase the risk of BBV and SSTI acquisition, such as needle/syringe sharing, groin injection and polydrug use. Harm reduction and drug treatment services should adapt to support the needs of this growing population of people injecting stimulants.

Community-based respondent-driven sampling as a strategy for drug use surveillance in a large French urban area

BACKGROUND

Understanding drug use and behavior within the PWUD population is crucial to adapt harm reduction and prevention strategies, and provide improved addiction and medical treatment. However, in most countries such as France, the knowledge of drug use behaviors is likely biased as it originates from addiction centers which are attended by only an unknown proportion of PWUD. The objectives of this study were to describe drug use behavior in a population of active PWUD in the urban area of Montpellier, South of France.

METHODS

We implemented a community-based respondent-driven sampling survey (RDSS), a validated strategy to obtain a representative sample of a population, to recruit PWUD in the city. Adult individuals reporting frequent psychoactive drug use other than cannabis, with confirmation by urine test, were eligible. Beside HCV and HIV testing, trained peers interviewed participants on their drug consumption and behavior using standardized questionnaires. Fifteen seeds launched the RDSS.

RESULTS

During the 11 weeks of the RDSS, 554 actives PWUD were consecutively included. They were mostly men (78.8%), had a median age of 39 years, and only 25.6% had a stable living place. On average, participants consumed 4.7 (± 3.1) different drugs, and 42.6% smoked free-base cocaine. Unexpectedly, heroin and methamphetamine were consumed by 46.8% and 21.5% of participants, respectively. Among the 194 participants injecting drugs, 33% declared sharing their equipment.

CONCLUSION

This RDSS highlighted a high consumption of heroin, crack and methamphetamine in this PWUD population. These unexpected results can be explained by low attendance to addiction centers, the source of drug use reports. Despite free care and risk reduction equipment in the city, sharing was very frequent among injectors, challenging the current program of harm reduction.

Spatial and temporal assessment of crack cocaine use in 13 European cities through wastewater-based epidemiology

Already in early 2000s, concerns have been growing in the EU about increasing use of cocaine and it is estimated that below 1 % of the population administer the drug by smoking crack cocaine. New available data suggests an increase in the use of crack cocaine and an increase in the number of crack cocaine users entering treatment has been reported in several European countries. Robust estimations of crack cocaine use are however not available yet. The use of crack cocaine has long been associated with severe adverse socio-economic conditions as well as mental health problems, such as suicide ideation and depression. The aim of this study was to assess spatial trends in population-normalized mass loads of crack cocaine biomarkers (i.e., anhydroecgonine and anhydroecgonine methyl ester) in 13 European cities in six countries (the Netherlands, Belgium, Ireland, Portugal, Spain and Italy). Furthermore, temporal trends over a five-year period were evaluated through the analysis of historic samples collected in the Netherlands. Finally, the stability of the crack cocaine biomarkers in wastewater was investigated through batch experiments. The samples were analyzed with a new developed and validated hydrophilic interaction liquid chromatography coupled to mass spectrometry method. Targeted crack cocaine biomarkers were found in all cities. Also, crack cocaine biomarker was detected in wastewater from 2017 to 2021 in the Netherlands, but no significance between the years were found. With respect to biomarker in-sample stability, AEME was found to be stable in wastewater. This study assessed crack cocaine use for the first time on a broad scale, both temporal and in cities across Europe, with wastewater-based epidemiology and it shows the importance of wastewater analysis to monitor community loads of crack cocaine use.

Sociological and spatial dynamics of an evolving Parisian open drug scene: the case of the “Colline du Crack”

Purpose

In November 2019, an open drug scene, commonly called “Colline du crack” and located in Paris was forcibly closed after 10 years of existence. This paper aims to understand how that space has evolved over the years to become a major hub for drug use.

Design/methodology/approach

The authors used a qualitative approach that included interviews with 52 people who use drugs (PWUD) and 54 field professionals and ethnographic observations. The authors asked questions about the evolution of the major sites of crack visibility in Paris and about social representations related to these spaces. They compared their datas with datas drawn from gray literature.

Findings

La Colline emerged on an isolated slope, away from police repression and local anti-crack organizations. In the beginning, it was a discrete, communal space regulated by PWUD. Starting in 2015, social transformations in the neighborhood turned la Colline into a central hub for dealing and using crack. La Colline became an open scene which led to its evacuation in 2019.

Originality/value

This paper contributes to literature on community building of drug consumers. The authors are also using a wide variety of methodological tools.