Current HCV Screening, Treatment Strategies Projected to Fall Short of WHO Goals

William Wong, PhD

Credit: ResearchGate

Current prevention, screening, and treatment strategies will not be sufficient to fully meet the World Health Organization (WHO) goals for reducing hepatitis C virus (HCV) incidence and deaths, according to findings from a recent study.¹

Projections from an agent-based model simulating the dynamics of HCV transmission and demographic changes from 2006-2030 using data from Ontario, Canada, suggest even with the implementation of extensive increases in screening and treatment, the mortality target may be achievable, but the target for preventing new chronic HCV cases is likely unattainable, highlighting the importance of developing enhanced harm-reduction strategies.¹

In 2016, the World Health Assembly unanimously adopted the resolution calling for the elimination of viral hepatitis by 2030. In the same year, the WHO published a Global Health Sector Strategy on viral hepatitis to reach this goal, defining elimination as a 90% reduction in incidence and a 65% reduction in mortality for hepatitis B and C from 2015 to 2030.²

“Various model-based studies have demonstrated the projection of HCV elimination for different countries. However, most models used have not yet considered the impact of transmission dynamics; COVID-19; and ongoing immigration,” William Wong, PhD, associate professor and CIHR Applied Public Health Chair in HIV and STBBI Research at the University of Waterloo, and colleagues wrote.¹ “Thus, existing models may fail to generate accurate projections necessary to assess the impact of interventions, particularly related to CHC incidence.”

To address these shortcomings of current models and project the incidence and prevalence of HCV-related health outcomes under current and prospective HCV intervention strategies, investigators developed an agent-based model including 12.2 million individuals representative of the population living in Ontario, Canada, based on the population census. The model simulation started in 2006 and incorporated the impact of immigration, births, and deaths from 2006 onward, as well as the negative impact of the COVID-19 pandemic starting in 2020.¹

To identify the best strategy to achieve HCV elimination by 2030, investigators considered 4 combinations of prevention, screening, and treatment strategies for the general population:

• Current risk-based prevention, screening, and treatment strategy (status quo)
• Aggressive treatment strategy: 90% increase in patients treated compared with the status quo
• Aggressive screening and treatment strategy: 90% increase in people screened and 90% increase in patients treated compared with the status quo
• Enhanced harm-reduction strategy: 90% reduction in transmission risk among people who inject drugs (PWID) compared with the status quo

Investigators forecasted the incidence of acute hepatitis C, chronic hepatitis C, chronic hepatitis C-induced decompensated cirrhosis, chronic hepatitis C-induced hepatocellular carcinoma, and chronic hepatitis C-induced liver-related deaths, as well as the prevalence of chronic hepatitis C in Ontario from 2015 to 2030 for each strategy.¹

Acute Hepatitis C Incidence

The agent-based model predicted the total incidence of acute hepatitis C in Ontario would slowly decrease by 6.9% from 2015 to 2030 under the status quo, while the total incidence of acute hepatitis C resulting from the “aggressive treatment strategy” and the “aggressive screening and treatment strategy” decreased by 12.6% and 15.8% from 2015 to 2030, respectively. Of note, both the status quo and the aggressive screening and treatment strategies fall below the WHO target of an 80% reduction in HCV incidence.¹

In contrast, investigators pointed out the enhanced harm-reduction strategy had the largest effect on lowering the incidence of acute hepatitis C, resulting in an 85.4% reduction from 30.0 cases per 100,000 population in 2015 to 4.4 cases in 2030.¹

Chronic hepatitis C Incidence, Prevalence

The agent-based model predicted the total incidence of chronic hepatitis C in Ontario would decrease by 11.1% overall from 2015 to 2030 under the status quo, while the total incidence resulting from the “aggressive treatment strategy” and the “aggressive screening and treatment strategy” would decrease by 15.4% and 18.2% from 2015 to 2030, respectively. Regarding acute hepatitis C, investigators noted the enhanced harm-reduction strategy was the most effective, reducing the chronic hepatitis C incidence rate by 67.2%, from 28.7 cases per 100,000 population in 2015 to 9.4 cases in 2030.¹

Owing to the availability of DAA treatment, the current status quo would result in a 57.6% decrease in the total prevalence of chronic hepatitis C in Ontario from 2015 to 2030. The aggressive treatment strategy, the aggressive screening and treatment strategy, and the enhanced harm-reduction strategy would reduce chronic hepatitis C prevalence by 65.1%, 71.3%, and 70.9% from 2015 to 2030, respectively.¹

Advanced Liver Disease Incidence

Based on the status quo, the incidence of hepatitis C-induced decompensated cirrhosis and hepatitis C-induced hepatocellular carcinoma would decrease by 79.4% and 76.1% from 2015 to 2030, respectively. Implementation of the aggressive screening and treatment strategy would result in decreases of 85.6% and 83.4% from 2015 to 2030, respectively.¹

In terms of chronic hepatitis C-induced liver-related death, the current strategy, the enhanced harm-reduction strategy, and the aggressive treatment strategy would lead to a 62.1%, 63.2%, and 72.6% reduction in incidence from 2015 to 2030, respectively. Investigators pointed out the aggressive screening and treatment strategy can further increase the percentage reduction in the incidence of CHC-induced liver-related deaths to 72.9%, from 6.4 cases per 100,000 population in 2015 to 1.7 cases in 2030.¹

Investigators acknowledged multiple limitations to these findings, including the use of historical census data to generate model population characteristics; the limited COVID statistics available and incorporated into the model; the lack of consideration for changes in the ongoing opioid epidemic; and the inability to account for coinfection with other diseases.¹

“Current risk-based screening, and subsequent treatment, will be inadequate to achieve WHO goals,” investigators concluded.¹ “With extensive scale-up in screening, and treatment, the mortality target may be achievable, but the target for preventing new CHC cases is unlikely reachable, highlighting the importance of developing enhanced harm-reduction strategies for HCV elimination.”

References

1. ^{Tian F, Forouzannia F, Feng Z, et al. Feasibility of hepatitis C elimination by screening and treatment alone in high-income countries. Hepatology; doi:10.1097/HEP.0000000000000779}
2. ^{Coalition for Global Hepatitis Elimination. About Hepatitis Elimination. July 22, 2024. Accessed August 9, 2024. https://www.globalhep.org/about/about-hepatitis-elimination}