OBJECTIVES Injection drug use is a major risk factor for hepatitis C virus (HCV) infection; however, limited data on this topic are available in Korea. Thus, this study aimed to investigate the epidemiological and clinical characteristics, treatment uptake, and outcomes of HCV infection among people who inject drugs (PWID).

METHODS We used the data from the Korea HCV cohort, which prospectively enrolled patients with HCV infection between 2007 and 2019. Clinical data and results of a questionnaire survey on lifetime risk factors for HCV infection were analyzed according to a self-reported history of injection drug use (PWID vs. non-PWID group).

RESULTS Among the 2,468 patients, 166 (6.7%) were in the PWID group, which contained younger patients (50.6±8.2 vs. 58.2±13.1 years) and a higher proportion of male (81.9 vs. 48.8%) than the non-PWID group. The distribution of PWID showed significant regional variations. Exposure to other risk factors for HCV infection was different between the groups. The proportion of patients with genotype non-2 infection was higher in the PWID group. Treatment uptake was higher in the PWID group in the interferon era; however, it was comparable between the groups in the direct-acting antiviral era. The rate of sustained virological response did not significantly differ between the groups.

CONCLUSIONS As of 2019, PWID constituted a minority of HCV-infected people in Korea. The epidemiological characteristics, but not treatment uptake and outcomes, were different between the PWID and non-PWID groups. Therefore, active HCV screening and treatment should be offered to PWID in Korea.