Epidemiology and treatment status of hepatitis C virus infection among people who have ever injected drugs in South Korea: a prospective multicenter cohort study from 2007 to 2019 in comparison with non-PWID

Objectives Injection drug use is a major risk factor for hepatitis C virus (HCV) infection; however, limited data are available in South 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 the questionnaire survey focused on the lifetime risk factors for HCV infection were analyzed based on the self-reported history of injection drug use. Results Among the 2,468 patients, 166 (6.7%) had a history of injection drug use (PWID group). In the PWID group, the patients were younger (50.68.2 vs. 58.213.1 years) and the proportion of males was higher (81.9% vs. 48.8%) than in 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 differ between the groups. Conclusion By 2019, PWID were a minority among the HCV-infected people in Korea. The epidemiological characteristics were different between the groups, but not the treatment uptake and outcomes. Therefore, active screening and treatment should be offered to PWID in Korea.