Injecting Drugs Often Leads to HCV Reinfection Which Reduces Over Time

Alain H. Litwin, MD, MPH

Credit: Clemson, School of Health Research

A high rate of people who injected drugs had a hepatitis C virus (HCV) reinfection in the period immediately following sustained virologic response (SVR), a recent study found.¹

“Rates of reinfection were highest during the initial post-SVR period and decreased progressively with longer follow-up, highlighting the importance of early intervention to prevent reinfection,” wrote investigators, led by Alain H. Litwin, MD, MPH, from the department of medicine at University of South Carolina School of Medicine.

Nearly 2.4 million US adults had an HCV infection between 2013 and 2016. Between 2014 and 2018, new HCV infections increased by 71% because of the opioid crisis with many people turning to injection drugs.

According to the World Health Organization (WHO), approximately 50 million people have chronic hepatitis C virus infection, with about 1 million new infections occurring each year.² Many people who inject drugs worry about an HCV reinfection after treatment. Due to these concerns, investigators sought to assess the incidence of HCV reinfection and associated risk factors.¹

Investigators, led by Alain H. Litwin, MD, MPH, from the department of medicine at the University of South Carolina School of Medicine, conducted a secondary analysis of a randomized clinical trial that was conducted throughout several opioid treatment programs and community health centers in the US between September 2016 and August 2018. Participants who injected drugs and received a sustained virologic response were followed for up to 42 months.

The sample included 415 participants with a mean age of 44.7 years (range: 18 – 70 years) and 72.8% males. Participants had an HCV infection and active IDU within 90 days before screening.

Participants included in the study achieved a sustained virologic response and had ≥ 1 post-sustained virologic response assessment for HCV RNA. Among the sample, 72.8% reported a recent drug injection, 46.3% lived in unstable housing, and 75.4% received recent methadone or buprenorphine for opioid use disorder (OUD).

Participants were randomized 1:1 to the arms patient navigation (PN) or modified directly observed therapy (mDOT) and received sofosbuvir and velpatasvir once daily for 12 weeks. Participants in the PN group were observed ≥ 5 days per week and had take-home doses the rest of the week.

After the treatment, patients had study visits every 12 weeks for 168 weeks. The follow-up visits gathered data on sociodemographic factors, alcohol, other drug use, injecting behaviors, treatment for substance use, depression, anxiety, and quality of life. At every follow-up, patients had their HCV RNA evaluated by Quest Diagnostics (COBAS TaqMan), and urine specimens were assessed for the presence of amphetamines, benzodiazepines, cocaine, and opioids.

The analysis was performed in March 2022. The team assessed change in reinfection rates over time using a Poisson regression model.

The reinfection rate was 11.4 per 100 person-years at risk (95% confidence interval [CI], 8.7 – 14.7 per 100 person-years) over 518 person-years of follow-up. Reinfection rates varied across sites, ranging from 2.9 per 100 person-years at risk (95% CI, 0.1 – 16.3 per 100 person-years) to 25.2 per 100 person-years at risk (95% CI, 15.6 – 38.5 per 100 person-years at risk) (P = .006).

Increasing post-SVR follow-up significantly reduced incident reinfection (weeks 0 – 24, 15.5 per 100 person-years; 95% CI, 10.3 – 22.3 per 100 person-years; week 73 – 144 per 100 person-years; 95% CI, 0.9 – 12.5 per 100 person-years; 95% CI, 0.9 – 12.5 per 100 person-years (P = .008).

“Our results reinforce previous reports showing that most reinfections occur within 24 weeks of SVR, emphasizing the need to offer effective interventions early to prevent reinfection,” investigators wrote.

Participants aged ≥ 40 years had lower reinfection rates than younger participants (adjusted incidence rate ratio [aIRR], 0.32; 95% CI, 0.18 – 0.57). Moreover, participants who did not have any methamphetamine detected in urinary drug screening had lower reinfection rates than participants who had methamphetamine detected (aIRR, 0.41; 95% CI, 0.21 – 0.82). Participants who reported having a drug injection within the previous 3 months had a greater risk of reinfection than participants who did not recently have a drug injection (aIRR, 3.33; 95% CI, 1.86 – 5.97).

Investigators wrote the results were limited by a predominately urban setting and differences in participant characteristics, particularly those lost to follow-up, which could lead to an underestimation of accurate reinfection rates. Additionally, the absence of phylogenetic testing and the exclusion of potentially reinfected participants before the SVR assignment may have further obscured the study's findings.

“Clinicians and public health leaders should provide full access to treatment in injecting networks and communities all at once to reduce community viral load through the implementation of simplified algorithms for treatment and decentralized models of care,” investigators wrote. “These data will inform public health strategies to achieve HCV elimination and minimize reinfection through identification of high-risk behaviors and the implementation of appropriate interventions for PWID who require more intensive or frequent follow-up and prompt retreatment.”

References

1. ^{Litwan, A, Tsui, J, Heo, M, et al. Hepatitis C Virus Reinfection Among People Who Inject Drugs. JAMANetworkOpen.2024;7(8):e2430024.doi:10.1001/jamanetworkopen.2024.30024.}
2. ^{Hepatitis C. World Health Organization. April 9, 2024. https://www.who.int/news-room/fact-sheets/detail/hepatitis-c#:~:text=Globally%2C%20an%20estimated%2050%20million,carcinoma%20(primary%20liver%20cancer). Accessed August 26, 2024.}