Perspectives and control of hepatitis B virus infection in Taiwan.

Hepatitis B virus (HBV) infection is endemic in Taiwan. After the implementation of universal hepatitis B vaccination, there was a significant reduction of hepatitis B surface antigen (HBsAg) seropositivity and HBV-related hepatocellular carcinoma (HCC) incidence in children, teenagers, and young adults. However, the incidence of HBV-related HCC in adults remains high. Through several community- and hospital-based cohort studies, the viral factors affecting the prognosis of HBV carriers have been illustrated. Serum HBV DNA level > 2000 IU/mL at study entry starts to increase the risks of cirrhosis and HCC in adult patients with chronic HBV infection. In addition, serum HBsAg level > 1000 IU/mL is associated with a higher risk of HCC in HBeAg-negative patients with low viral load. Virologically, HBV genotype C/D and core promote/pre-S mutations correlate with an increased HCC risk. Recently, a risk calculator has been developed to predict HCC in noncirrhotic patients with external validation. Therapeutically, hospital-based cohort and population-based nationwide studies indicated that interferon and nucleos(t)ide analogue treatments could reduce the incidence of HCC over time. Towards the ultimate goal of HBV eradication, several novel agents aiming at viral and host targets are under development. In addition, the immune therapy may play a key role in HBV cure in the foreseeable future.