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.

Reaching Hard-to-Reach People Who Use Drugs: A Community-Based Strategy for the Elimination of Hepatitis C.

Background: Elimination of hepatitis C virus (HCV) among people who use drugs (PWUD) remains a challenge even in countries in which HCV care is provided free of cost. We assessed whether an innovative community-based, respondent-driven sampling (RDS) survey, coupled with HCV screening and immediate treatment, could be efficient to detect and cure current PWUD with chronic HCV in a large city of Southern France. Methods: At a community site with peers, PWUD (cannabis not included) were enrolled after confirmation by a urine drug test. Participants were then screened for hepatitis B virus, HCV, and human immunodeficiency virus and benefited from onsite HCV treatment evaluation and prescription. Peer support was provided during treatment, and a systematic visit was scheduled 12 weeks after the end of treatment. The cost of the intervention was estimated. Results: Five hundred fifty-four participants were enrolled. Most were male (78.8%) with a median age of 39 years (interquartile range, 33-46). Cocaine (73.1%) and heroine (46.8%) were the main drugs consumed. Overall, 32.6% of PWUD (N = 181) were HCV seropositive, 49 (27.1%) of which had detectable HCV ribonucleic acid and were thus eligible for treatment. Ten of these patients had severe fibrosis. Hepatitis C virus treatment was initiated for 37 (75.5%) patients, 30 (81.1%) of whom completed their treatment and 27 (73.0%) achieved sustained viral response at week 12. The total cost was 161 euros € per screened patient and 1816€ per patient needing treatment. Conclusions: A community-based RDS survey approach, involving peers, proved efficient and cost-effective to reach and cure PWUD for HCV. This innovative strategy could be key for the final step of HCV elimination. Clinical trial registration. ClinicalTrials.gov, NCT04008927.