课件：乙型肝炎的中医药治疗_西安丙肝医院.ppt

* Key messages Hepatitis B is one of the most common infectious diseases in the world. There are 350 million chronic carriers of the hepatitis B virus worldwide. Hepatitis B is the ninth leading cause of death worldwide. Geographical prevalence varies widely throughout the world. Nearly 75% of HBV chronic carriers are Asian. Points of explanation The geographical prevalence of hepatitis B varies from a highly endemic disease in Asia and Africa to a disease of low prevalence in North America and Western Europe. Additional information More than 2 billion people worldwide have been infected with HBV though not all of these have become chronically infected. The majority of hepatocellular carcinoma in Asia results from hepatitis B virus infection References Margolis HS, Alter JH, Habler SC. Hepatitis B: evolving epidemiology and implications for control. Sem Liver Dis 1991;11:84-92 Mast EE, Alter JH. Epidemology of viral hepatitis: an overview. Sem Viral 1993;4:273-283 World Health Organisation Data * Key messages Routes of transmission for hepatitis B vary widely. In highly endemic regions, the most common routes of transmission are perinatal transmission and child to child transmission. In North America and Western Europe sexual transmission, IV drug use and accidental exposure to infected blood are the more common routes of transmission. Points of explanation HBV is one of the most infectious viruses known and chronic carriers have a large amount of virus in their serum. To infect the liver, the hepatitis B virus must have access to the blood circulation directly or by crossing mucous membranes. Additional information The marked differences observed in the global prevalence of HBV infection are associated with variations in the predominant routes of HBV transmission. References Kurstak E et al. Viral Hepatitis: current status and issues. Springer-Verlag Wien New York, 1993. Margolis HS, Alter JH, Habler SC. He