Reinfection rates of hepatitis C virus (HCV) following treatment with direct-acting antivirals (DAA) were assessed in a large, population-based cohort study presented at The Liver Meeting 2018.
In order to determine HCV reinfection rates following sustained virologic response (SVR) in the overall population as well as in PWID, the study authors analyzed data obtained from a population-based study that included >1.7 million people that were tested for HCV. “We assessed HCV-infected individuals treated with DAAs between 1/1/2014 and 7/1/2017 who achieved SVR and had ≥1 subsequent HCV RNA test for reinfection,” the study authors explained. Reinfection was defined as one positive HCV RNA test following SVR and persistent reinfections were considered in patients who did not spontaneously clear.
An algorithm derived from physician diagnosis and hospitalization codes was utilized to assess current (<3 years prior to SVR) and former (≥3 years prior to SVR) PWID. The study authors stated, “Crude reinfection rates per 100 person-years (PYs) were calculated and Poisson regression was used to model age and sex-adjusted incidence rate ratios (IRRs).”
A total of 4,114 patients were included in the study, of which, 21% were current PWID and 44% were former PWID; 5% of PWID reported using opiate agonist therapy (OAT).
The study authors reported that the reinfection rate was calculated to be 1.45/100 person-years (PYs) and 1.19/100 PYs for persistent reinfection. Additionally, higher crude reinfection rates were observed in current PWID (3.1/100 PYs; IRR: 8.0; 95% CI: 2.4, 27) compared to former PWID (1.4/100 PYs; IRR: 4.2; 95% CI: 1.2, 14) and non-PWID (0.3/100 PYs).
Data analysis also found reinfection rates in current PWID to be higher for patients <45 years old compared to those ≥45 years old (10.4/100 PYs vs 2.0/100 PYs, respectively) as well as in male patients compared to female patients (3.8/100 PYs vs 1.7/100 PYs, respectively). The study authors added, “Among PWID, OAT use ≥28 days since completing therapy was associated with a non-significant reduction in reinfection risk (1.5 vs. 2.1/100 PYs, IRR: 0.7, 95% CI: 0.1, 3.3).”
According to the results of this study, HCV reinfection rates appear to be elevated following DAA therapy in PWID. “Interventions to reduce reinfection risks are necessary to prevent ongoing transmission,” the study authors concluded.
Rossi C, et al, Hepatitis C Virus Reinfection after Successful Treatment with Direct-Acting Antiviral Therapy in a Large Population-Based Cohort. Presented at AASLD The Liver Meeting 2018. Study number 1593.