VIRAL HEPATITIS (Part - II)

HB was formerly called serum hepatitis. It occurs worldwide, more than 2000 million people having already been infected with HB virus (HBV). Sub clinical infection are common. An icteric infection is four times the icteric episode. Besides causing acute hepatitis the disease tends to chronic and often causes carrier state, subacute hepatitis, cirrhosis and primary hepatocellular carcinoma (HCC). HBV is an important cause of HCC, which is one of the commonest cancers in the world. Hundreds of thousands of persons die of this type of cancer each year. Hepatitis B infection accounts for 60 to 80% of primary liver cancer worldwide. HB is upto 100 times more infectious than HIV and HB is second only to tobacco as cause of major cancer in humans. The chance discovery of Australia antigen now known as HBsAg revolutionized the study and control of HBV infection. The pathological and clinical manifestation of HBV infection are a result of cellular and immune response of the host.^1-5