Researchers reveal regional disparities in hepatitis C prevalence

The National Cancer Center (NCC) said Friday that a team of researchers led by Professor Ki Mo-ran of the Department of Public Health and AI at the NCC’s Graduate School of Cancer Science and Policy (GCSP) has published an analysis of hepatitis C prevalence trends by city, county, and district across the country.

Hepatitis C is a disease in which the liver becomes inflamed due to the body’s immune response to infection with the hepatitis C virus (HCV). About 70–80 percent of those infected develop chronic hepatitis C. Still, the disease is difficult to detect early because it often presents with few symptoms in its initial stages. If left untreated, 15–51 percent of cases progress to cirrhosis over 20–30 years, and the annual risk of liver cancer in cirrhosis patients is 1–5 percent. Although hepatitis C has effective treatments, early detection remains difficult, and many people with the disease are unaware of their condition and do not seek timely care.

The research team analyzed hepatitis C prevalence in Korea over the past 18 years, from 2005 to 2022. Using big data from the National Health Insurance Service, they examined the prevalence in 17 provinces and 257 municipalities nationwide, identifying areas that require priority management.

The study tracked hepatitis C prevalence over time and pinpointed Boeun-gun in North Chungcheong Province, Sunchang-gun in North Jeolla Province, and Jindo-gun in South Jeolla Province as high-risk counties—adding to existing high-risk areas such as Busan, South Gyeongsang Province, and South Jeolla Province.

The results showed that the national prevalence rate per 100,000 population decreased from 151 in 2005 to 98 in 2022, with an average annual decline of 2.7 percent. Notably, the rate dropped more sharply between 2018 and 2022, with an average annual decrease of 10.4 percent.

In 2022, Busan had the highest prevalence rate, with 210 cases per 100,000 people, followed by South Gyeongsang Province with 131 and South Jeolla Province with 127. These three regions recorded higher prevalence rates than the national average over the 18-year period. In contrast, North Chungcheong Province had the lowest rate, with 40 cases per 100,000 people.

By city and county, Namhae-gun in South Gyeongsang Province (2005), Boeun-gun in North Chungcheong (2006–2008), Sunchang-gun in North Jeolla (2009–2015, 2018–2019), Jindo-gun in South Jeolla (2016–2017, 2020), and Seo-gu in Busan (2021–2022) recorded the highest prevalence rates in their respective years.

The greatest decline in prevalence occurred in Boeun-gun, which dropped from 361 cases in 2005 to 34 in 2022, representing an average annual decrease of 23.7 percent. The largest increase was in Gunwi-gun, North Gyeongsang Province, where the rate rose from 64 in 2005 to 87 in 2022—an average annual increase of 3.0 percent.

“Although the overall prevalence of hepatitis C in Korea is declining, regional disparities persist,” Professor Ki said. “To achieve the World Health Organization’s (WHO) goal of eliminating hepatitis C, intensive and prioritized management is needed in areas with recent increases in prevalence, as well as in known high-risk regions such as Busan, South Jeolla, and South Gyeongsang provinces.”

The study was supported by the National Cancer Center’s Cancer Research in the Public Interest Industry Grant, and the findings were published in the international journal BMC Public Health.