Epidemiology of viral hepatitis C: Road to elimination in Japan

Abstract

Although HCV infection was the main cause of HCC in Japan contributing 70% over two decades after its first cloning in 1989, it was markedly decreased to 49% in 2013 and expected to decrease continuously. Based on blood donor national database, the new incident cases were 0.4/100,000 person-years, the prevalence was 0.13% and the total number was 890,902-1,302,179 in 2015. Establishment of blood donor screening with anti-HCV measurement and nucleic acid test introduced by Japanese Red Cross as pioneer, high-level medical and surgical care, and the government's policy under the Basic Act on Hepatitis Control have changed its epidemiology and outbreak trend and also enforced the disruption of potential transmission cascades. HCV prevalence among the younger generation was extremely low in all regions, and the predominant age for HCC has shifted to over 60 years old population. Considering such changes, HCV induced HCC occurrence is supposed to be ultimately suppressed in the near future. However, taking into account society changes, regulating intravenous drugs users and monitoring high-risk groups such as tattoos, and men who have sex with men are indeed required in Japan. Understanding the epidemiological changes in HCV is important in assigning, modifying, and designating effective response systems. Selective or national action plans, strategic approaches, and cooperation between government sectors have a positive impact on HCV prevention and control. A dramatic decrease in total number of HCV carriers, increase in number of people treated with highly effective DAA, and subsequent high SVR indicates Japan might achieve WHO's target of HCV elimination by 2030.