Abstract
Objective: We examined methadone use among a large cohort of individuals undergoing serologic testing for hepatitis C virus (HCV) infection.
Methods: In British Columbia, community pharmacy methadone dispensations are recorded in the PharmaNet database and HCV antibody (anti-HCV) test results are recorded by the Provincial Public Reference Laboratory. Provincial HCV laboratory testing records from 1992 to 2004 were linked to methadone dispensation records from 1995–2006. We describe methadone maintenance treatment (MMT) among individuals undergoing anti-HCV testing between 1992 and 2004.
Results: Between 1992 and 2004, 404,941 individuals were tested for anti-HCV in BC; 32,918 (8%) were positive. Overall, methadone was dispensed to 10,314 (2.5%) of individuals tested for anti-HCV; 1% of negative testers and 21% of positive testers. Of 10,314 individuals receiving methadone, 6,732 (65%) had a positive anti-HCV test during the study period. Laboratory anti-HCV serostatus was known at MMT initiation in 70%; of these, 2,596 (36%) were anti-HCV negative and 4,638 (64%) were anti-HCV positive at first methadone dispensation. Seroconversion from anti-HCV negative to positive following MMT initiation was confirmed in 288 persons.
Conclusion: Methadone used in conjunction with other harm reduction initiatives can reduce the transmission of blood-borne infections among individuals who inject opiates, however many who enter the BC Methadone Program are already anti-HCV positive and others seroconvert after MMT initiation. Our data suggest there are missed prevention opportunities for MMT and other harm reduction services. Linkage of laboratory and health service data can provide a population lens to identify and evaluate potential prevention strategies.
Key words: Hepatitis C, injection drug use, methadone, addiction, harm reduction
Résumé
Objectif: Étudier l’utilisation de la méthadone dans une vaste cohorte de sujets ayant passé un test sérologique de dépistage du virus de l’hépatite C (VHC).
Méthode: En Colombie-Britannique (C.-B.), les distributions de méthadone par les pharmacies communautaires sont enregistrées dans la base de données PharmaNet, et les résultats des tests de sérodétection des anticorps anti-VHC sont enregistrés par le laboratoire de référence provincial. Nous avons relié les données des épreuves de laboratoire provinciales pour le VHC de 1992 à 2004 aux données de distribution de méthadone de 1995 à 2006. Nous décrivons le traitement de maintien à la méthadone (TMM) chez les sujets ayant subi un test sérologique anti-VHC entre 1992 et 2004.
Résultats: Entre 1992 et 2004, 404 941 personnes ont passé un test anti-VHC en C.-B.; 32 918 de ces tests (8 %) étaient séropositifs. Dans l’ensemble, la méthadone a été distribuée à 10 314 (2,5 %) des personnes testées pour le VHC: 1 % des sujets séronégatifs et 21 % des sujets séropositifs. Sur les 10 314 personnes ayant reçu de la méthadone, 6 732 (65 %) avaient eu un test anti-VHC positif durant la période de l’étude. L’état sérologique pour le VHC déterminé en laboratoire était connu au début du TMM dans 70 % des cas; sur ces personnes, 2 596 (36 %) étaient séronégatives pour le VHC et 4 638 (64 %) étaient séropositives pour le VHC à la première distribution de méthadone. La séroconversion d’un statut séronégatif pour le VHC à un statut séropositif après le début du TMM a été confirmée chez 288 personnes.
Conclusion: La méthadone, utilisée conjointement avec d’autres méthodes de réduction des méfaits, peut réduire la transmission des infections véhiculées par le sang chez les utilisateurs d’opiacés par injection, mais un bon nombre des sujets qui s’inscrivent au programme de méthadone de la C.-B. sont déjà séropositifs pour le VHC, et d’autres le deviennent après le début du TMM. Ces données montrent qu’il pourrait y avoir des occasions de prévention manquées par le TMM et d’autres services de réduction des méfaits. Le jumelage des données des laboratoires et des services de santé peut fournir une optique en population pour définir et évaluer les stratégies de prévention possibles.
Mots clés: hépatite C; toxicomanie intraveineuse; méthadone, dépendance; réduction des dangers
Footnotes
Conflict of Interest: None to declare.
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