Challenges in hepatitis C elimination despite highly effective antiviral agents in patients with and without intravenous drug use.

Aim: To assess the adherence to treatment, sustained virologic response (SVR) rate, and reinfection rate in hepatitis C patients with and without intravenous drug use.

Methods: This retrospective study included hepatitis C patients, evaluated and treated in our hepatology outpatient clinic between January 2014 and October 2019. The following information was extracted from the patient's file: the presence of positive viral load for hepatitis C virus (HCV), active and recent (in the last 6 months) use of i.v. drugs, HCV genotype, treatment regimen, SVR, HCV reinfection rate, coinfection with human immunodeficiency virus (HIV) and ongoing opioid substitution therapy (OST).

Results: We included 431 hepatitis C patients, 234 people who inject drugs (PWID) and 197 non-PWID. Most patients were treated with direct-acting antivirals (DAA) only. The rate of documented SVR by treated patients was significantly higher in the non-PWID cohort (91.5% vs. 61.5%, p < 0.0001), while noncompliance (did not show up to start treatment) rate or refusal of treatment was significantly higher in the PWID cohort (19.4% vs. 8.9%, p = 0.004). In the PWID cohort, younger age and recent (in the last 6 months) or ongoing i.v. drug use was associated with noncompliance: 31.1 ± 8.4 years vs. 35.8 ± 10.6 years (p = 0.02) and 33.3% vs. 12.8% (p = 0.0008), respectively. Ongoing OST was associated with better compliance: 61.1% vs. 46.1% (p = 0.04).

Conclusion: To achieve elimination of hepatitis C better treatment strategies are needed, especially in PWIDs.