Direct-acting antivirals could reduce HCV prevalence by 80%

Novel direct-acting antiviral (DAA) therapies could reduce the prevalence of hepatitis C virus (HCV) by more than 80%, suggesting that HCV infections could be eliminated in the U.S. if enhanced screening and treatment efforts targeted high-risk populations, according to a new study.

Interferon-free DAAs have opened a new frontier in HCV treatment, raising the possibility of not only preventing HCV-associated complications and deaths, but also interrupting transmission among people who inject drugs (PWIDs) and potentially eliminating HCV altogether.

"The key finding is that a four-fold increase to the number of patients treated each year could virtually eliminate HCV from the non-injecting population within a decade," senior author Jeffrey Townsend, associate professor of biostatics at Yale University in the School of Public Health, told Medical Economics.  More modest increases in screening and treatment would also markedly reduce new infections and mortality, he said.

The researchers published their results online on December 1, 2015 in Clinical Infectious Diseases.

Townsend and colleagues developed a transmission model that captures the impact of treatment on chronic disease and distinguishes screening and treatment as separate public health objectives. The model also accounts for underreporting in estimates of the national prevalence of HCV. Their analysis included outcomes such as cirrhosis, liver transplants and mortality.

“We found that HCV prevalence, HCV-associated liver disease and HCV-associated mortality in the United States can be substantially reduced through widespread treatment with DAAs. Total HCV prevalence is likely to fall by more than 80% within 10 to 20 years through treatment alone,” said Townsend.

Up to 150,000 additional cases could be identified by increasing HCV screening, effectively eliminating HCV from the non-drug injecting population.

Further opportunities exist to greatly reduce prevalence and new infections among PWIDs through targeted screening and treatment. Screening at emergency room visits can identify undiagnosed individuals, both among baby boomers as well as among PWIDs, and link them to care, he said. “Access to medical care in a nonjudgmental setting and provider-initiated screening has been shown to be effective in increasing HCV screening among PWIDs,” Townsend said.

In addition, interventions that incorporate enhanced screening and treatment with needle and syringe exchange programs could reduce transmission, and opiate substitution therapy could reduce the reservoir of drug users actively transmitting the virus.

“Persistence of HCV in the U.S. is likely unless we pay attention to eliminating HCV in PWIDs,” Townsend said. “HCV elimination should be the goal. That requires extremely high screening and treatment, which is not possible in the PWID population.”

He added “DAAs hold tremendous promise in terms of improving health outcomes and reducing transmission. Delivery of DAAs is tolerable with minimal adverse effects.”

However, the greater acceptance of DAAs must be tempered by their high costs and by limited insurance coverage, and the willingness to treat PWIDs, he said.

Townsend concluded: “Our analysis provides a forecast for the potential impact of DAAs in reducing HCV-associated liver disease, demonstrating that achievable expansion of HCV treatment at current screening rates can substantially reduce morbidity and mortality.”