Methadone Use in Relation to Hepatitis C Virus Testing in British Columbia

Abstract

We examined methadone use among a large cohort of individuals undergoing serologic testing for hepatitis C virus (HCV) infection. 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. 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, 6732 (65%) had a positive anti-HCV test during the study period. Laboratory anti-HCV serostatus was known at MMT initiation in 70%; of these, 2596 (36%) were anti-HCV negative and 4638 (64%) were anti-HCV positive at first methadone dispensation. Seroconversion from anti-HCV negative to positive following MMT initiation was confirmed in 288 persons. 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.