EPIDEMIOLOGY OF HEPATITIS-B VIRUS-INFECTION IN INDIA

The average estimated carrier rate of hepatitis B virus (HBV) in India is 4%, with a total pool of approximately 36 million carriers. Wide v ariations in social, economic, and health factors in different regions may explain variations in carrier rates from one part of the country to another. Professional blood donors constitute the major high risk g roup for HBV infection in India, with a hepatitis B surface antigen po sitivity rate of 14%. Blood transfusions represent the most important route of HBV transmission among adults. However, most of India's carri er pool is established in early childhood, predominantly by horizontal spread due to crowded living conditions and poor hygiene. Acute and s ubacute liver failure are common complications of viral hepatitis in I ndia and HBV is reckoned to be the aetiological agent in 42% and 45% o f adult cases, respectively. HBV is reported to be responsible for 70% of cases of chronic hepatitis and 80% of cases of cirrhosis of the li ver. About 60% of patients with hepatocellular carcinoma are HBV marke r positive. Small numbers of patients have been reported to be infecte d with the pre-core mutant virus but none with the S mutant. Coinfecti on with hepatitis C virus or hepatitis delta virus is comparatively un common. In conclusion, hepatitis B is a major public health problem in India and will continue to be until appropriate nationwide vaccinatio n programmes and other control measures are established.