The change in the nationwide seroprevalence of hepatitis C virus and the status of linkage to care in South Korea from 2009 to 2015

Background: Hepatitis C virus (HCV) requires epidemiological monitoring to estimate its disease burden and to develop countermeasures. This study aimed to investigate the difference between the 2015 and 2009 nationwide anti-HCV seroprevalence and to determine linkage to care estimates in South Korea. Methods: A total 268,422 examinees ≥ 20 years old were included in 2015 from 33 medical institutions nationwide. Electronically extracted data were retrospectively analyzed to calculate the age-, sex-, and area-adjusted anti-HCV prevalence. Seroprevalence in 2015 was measured using the same method as that in 2009. For anti-HCV-positive subjects, medical records were reviewed to see whether HCV RNA testing or antiviral treatment was performed. Results: Adjusted anti-HCV prevalence was 0.60% (95% confidence interval, 0.57–0.63) based on general Korean population in 2015. It showed an increasing trend according to age; 0.23% in thirties, 0.38% in forties, 0.63% in fifties, 1.08% in sixties, and 1.65% in those aged ≥ 70 years. From 2009 to 2015, the adjusted anti-HCV prevalence decreased by 30%, with odds ratio of 0.70 (95% CI 0.70–0.71). There was significant intranational regional variation and changing pattern of seroprevalence. Among 1359 anti-HCV-positive subjects, HCV RNA test was performed in 60% and 25.4% had positivity. Treatment-initiated and cured rates in 2015 were 18.5% and 10.9%, respectively. Conclusions: Anti-HCV prevalence in South Korea was 0.6% in 2015, showing a 30% decrease from that in 2009. Although the HCV RNA testing rate was increased since 2009, this remains suboptimal. Moreover, the treatment uptake rate should be improved in South Korea.