Hepatitis B

Hepatitis B
(HBV)

Medical Author: Tse-Ling Fong, MD
Medical Editor: Leslie J. Schoenfield, M.D., Ph.D.

• What is the scope of the problem?
• What kind of a virus hepatitis B?
• How does hepatitis B virus cause liver injury?
• How is hepatitis B spread (transmitted)?
• What are the symptoms of acute hepatitis B?
  • What determines the outcome of acute hepatitis B?
• What are the symptoms of chronic hepatitis B viral infection?
  • Chronic hepatitis B
  • Cirrhosis of the liver due to hepatitis B virus
  • Advanced cirrhosis of the liver due to hepatitis B virus
  • Hepatitis B virus primary liver cancer (hepatocellular carcinoma)
  • Hepatitis B virus involvement of organs outside of the liver (extra-hepatic)
• How is hepatitis B diagnosed?
  • HBsAg and anti-HBs
  • Anti-HBc
  • HBeAg, anti-HBe, and pre-core mutations
  • Hepatitis B virus DNA
  • How are the hepatitis B virus blood tests interpreted?
• What is the role of a liver biopsy in chronic hepatitis B?
• What is the natural progression or course of chronic hepatitis B?
  • What is the immune tolerant phase?
  • What is the immune clearance phase?
  • What is the quiescent phase?
  • What about flares and progression of chronic hepatitis B during the quiescent phase?
• What are healthy carriers of hepatitis B virus?
• What medications are used to treat hepatitis B?
  • What about interferon for the treatment of chronic hepatitis B?
  • How effective is lamivudine for the treatment chronic hepatitis B?
  • Why does hepatitis B virus become resistant to lamivudine?
  • Is interferon or lamivudine the preferred treatment for chronic hepatitis B?
• What are the effects of alcohol on hepatitis B virus?
• What are the effects of immunosuppressive medications on hepatitis B virus?
• What is delta hepatitis?
• What about co-infection of hepatitis B virus with hepatitis C virus?
• What happens in co-infection of hepatitis B virus with human immunodeficiency virus?
• What is the role of liver transplantation in hepatitis B viral infection?
• What can be done to prevent hepatitis B?
  • How effective is hepatitis B immune globulin (HBIG) in preventing hepatitis B?
  • How effective is vaccination for hepatitis B?
  • What is post-exposure immunoprophylaxis for hepatitis B virus?
  • How is transmission of hepatitis B virus from mother to newborn infant prevented?
• What is new in the treatment of hepatitis B virus?
• Hepatitis B At A Glance

What is the scope of the problem?

About one third of the world's population has been exposed at some time to the hepatitis B virus (HBV). Moreover, approximately 350 million individuals worldwide are chronically (long duration) infected with this virus. As a result, the complications of hepatitis B viral infection lead to two million deaths annually.

According to figures from the Centers for Disease Control (CDC), 140,000 to 320,000 cases of acute (short duration) hepatitis B (infection of the liver with hepatitis B virus) occur each year in the United States. Only about 50% of the people with acute hepatitis B, however, have symptoms (are symptomatic). Among symptomatic patients, 8,400 to 19,000 people are hospitalized and 140 to 320 die each year in the U. S. In the past decade, however, a more than 70% decrease in the incidence of acute hepatitis B has occurred in the U.S. This decrease may be related to heightened public awareness of HIV and AIDS and the resulting safer sexual practices. (hepatitis B virus and HIV are spread in very much the same way.) Currently, the highest incidence of acute hepatitis B is among young adults, especially Blacks and Hispanics, between the ages of 20 and 30.

Most adults (greater than 95%) with acute hepatitis B will recover completely. As a result, they will become immune to (that is, protected from) a future infection with hepatitis B virus. In contrast, most infants and children infected with acute hepatitis B virus will become chronically infected with the virus. Thus, in the U.S., an estimated 1 to 1.25 million people are chronically infected with hepatitis B virus. Furthermore, 5,000 to 6,000 people die each year from chronic hepatitis B virus liver disease and its complications, including primary (originating in the liver) cancer of the liver (hepatocellular carcinoma).

In some parts of the world, hepatitis B viral infection is always present (endemic) in the population. For example, in Southeast Asia and Sub-Saharan Africa, as many as 15 to 20% of adults are chronically infected with hepatitis B virus. In the U.S., such high rates of chronic infection are seen only among certain specific ethnic groups. These groups include native Alaskans, Pacific Islanders, and infants of first generation immigrant mothers from countries with high hepatitis B viral infection rates.

Source: MedicineNet.com
http://www.medicinenet.com/hepatitis_b/article.htm