Increased HCV diagnosis, treatment necessary to hit WHO elimination targets

The prevalence of hepatitis C infections has declined globally, but countries must scale up rates of diagnosis and treatment to achieve the WHO targets to eliminate HCV by 2030, according to new data.

“Our objective for this project was to evaluate the global prevalence of HCV and establish a new baseline for future elimination efforts,” Sarah Blach, MHS, CPH, HCV group team lead and an epidemiologist at the Center for Disease Analysis Foundation, said during an oral presentation at The Liver Meeting Digital Experience.

Updated prevalence data

For this study, Blach and colleagues, who previously published data on global estimates of HCV in 2015, included a literature search followed by a Delphi process to engage local experts and obtain consensus around country and territory data. They also incorporated mathematical modeling and extrapolated data on prevalence in countries for which data were not available from available regional averages. The researchers also built models for 110 countries, of which 80 were approved by country experts and 30 were estimated using published data only.

Notably, the estimated prevalence of HCV in 2015 in the current analysis was approximately 64 million, which was lower than the previously estimated prevalence of HCV in 2015 of 71 million, according to Blach.

“The main reason for this is we have new and higher-quality prevalence studies from Egypt, Brazil and Nigeria as well as a new estimated prevalence for the Democratic Republic of Congo, which really changed the prevalence in that region and lowered it quite a bit,” Blach said.

Between 2015 and 2019, there have been an estimated 7.5 million new chronic HCV infections, 8.8 million patients who have been cured and 5.5 million deaths among people who had a viremic infection.

“All of these things combined leave us with a new 2020 prevalence estimate of around 57 million viremic infections,” Blach said.

When comparing the 2015 and 2020 data at a country or territory level, the prevalence currently remains highest in countries in eastern Europe and central Asia. Some countries experienced substantial declines, but overall, the relative change in HCV prevalence from 2015 to 2020 for most countries only increased or decreased by approximately 10%, according to Blach.

After evaluating prevalence by number, however, Blach noted that more than half of all viremic infections were localized in just five countries, including China, Pakistan, India, Russia and the United States.

“In some of these countries, it’s also a little bit concerning because incidence is actually rising, such as in the United States, for example,” Blach said. “We really want to make sure we keep an eye on this and preventive measures to make sure new infections are reduced in these countries.”

Declines in treatment

In terms of treatment, approximately 10 million patients with HCV were initiated on direct-acting antivirals from 2015 to 2020. Interestingly, Blach noted, more than one-third of all treatments were in Egypt. This led to Egypt dropping from fifth to 17th place among the top 18 countries with the most viremic infections from 2015 to 2020.

Additionally, for most years between 2015 and 2018, the global average number of patients treated with DAAs was approximately 1.5 million to 2 million patients per year, with a peak in 2017 and a decline in 2018. Based on the 2017 peak, the traditional forecast suggests that treatment is expected to decline by approximately 50% over 5 years, according to Blach. However, although the researchers observed a significant spike in 2019 due to an additional 1.9 million patients being treated in Egypt, estimates based on data from approximately 30 countries show that estimates from 2020 are not only lower than the previous average of 1.5 million to 2 million patients treated per year but are also lower than the forecasted estimate, with only approximately 600,000 patients estimated to be treated in 2020.

“A couple of things account for this,” Blach said. “First, Egypt’s program has wrapped up and those patients have already been treated. Second, we also have the impact of countries not having enough patients who have been screened and diagnosed to maintain their previous treatment levels. And the third piece, of course, is the impact of the COVID-19 pandemic.”

Indeed, most countries showed a decrease in the number of patients initiating treatment in 2020 compared with 2019, with the exception of Rwanda, which has seen a substantial uptick in treatment due to a new national program, according to Blach.

Improvements in care needed

The researchers also assessed cumulative and annual cascades of care in high-income, upper-middle-income, lower-middle-income and low-income countries. For high-income countries, they estimated that approximately 65% of people with HCV in the 2015 population have already been diagnosed and approximately 45% of people with diagnosed infections initiated treatment from 2015 to 2019.

“This leaves a gap of about 3.5 million people who need treatment in high-income countries to reach that WHO elimination target,” Blach said. “Moving into the annual cascade, we see the number of people who are currently infected with HCV is actually a bit lower today; it’s actually about 6 million in that high-income group and about 47% of those who are still infected have been diagnosed and only 11% of those have been treated.”

Overall, these data do demonstrate a decline in the global prevalence of HCV, even after accounting for a new lower baseline. Blach noted, however, that less than one-quarter of all viremic infections globally are diagnosed and less than 10% have been treated.

“That means that there are still 57 million viremic infections remaining in 2020,” Blach said. “Historically, treatment has been highly concentrated in a few countries and so to achieve elimination goals, we really have to work on diversifying and getting those treatments out to other countries. Additionally, low diagnosis rates and lack of large-scale screening programs remain a barrier for elimination.”