HepatitisBOverview

Hepatitis is a general term which means inflammation of the liver. This inflammation of the liver can have different causes: infection, a disorder of the immune system, or exposure to alcohol, certain medications, toxins, or poisons.

Hepatitis B is caused by an infection with the Hepatitis B virus (HBV), a member of the Hepadnavirus family and one of several unrelated viral species which cause viral hepatitis. This infection has 2 phases: acute and chronic. The acute (new, short-term) phase occurs shortly after exposure to the virus. A small number of people develop a very severe, life-threatening form of acute hepatitis called fulminant hepatitis. The chronic (ongoing, long-term) hepatitis B is an infection with HBV that lasts longer than 6 months. Once the infection becomes chronic, it may never go away completely.

Hepatitis B is largely transmitted through exposure to bodily fluids(semen, saliva) containing the virus: unprotected sexual contact, blood transfusions, re-use of contaminated needles and syringes, vertical transmission from mother to child during childbirth, and so on. Hepatitis B is NOT transmitted through hugging, handshaking, breastfeeding, eating food or drinking water, casual contact (such as an office or social setting), and neither by sneezing or coughing.

In the United States approximately 200,000-300,000 persons become infected with HBV. More than 10,000 require hospitalization, and 250 die of fulminant disease. In addition, 22,000 HBV-infected women give birth each year. The prevalence of chronic HBV infection in the United States is 0.35%.

Approximately 5% of the world's population has chronic HBV infection; it is the leading cause of chronic hepatitis, cirrhosis, and hepatocellular carcinoma worldwide. An estimated 500,000-1,000,000 persons die annually from HBV-related liver disease. Countries are classified as follows: with low endemic rates (<2% of the general population has the antibody to the hepatitis B surface antigen [HBsAg]), intermediate endemic rates (2-8% positive for HBsAg), or high endemic rates (>8% positive for HBsAg).

In the United States, hepatitis B is largely a disease of young adults aged 20-50 years. The rate of progression of HPV from acute infection to chronic infection is determined by the age when the primary infection occurs: 90% during the perinatal period, 20-50% in children aged 1-5 years, and less than 5% in adults.

COMPLICATIONS

A major complication of Hepatitis B is fulminant hepatitis. The symptoms of fulminant hepatitis include hepatic encephalopathy that may evolve to deep coma, the liver is usually small, and the prothrombin time (a test that measures blood clotting ability) is excessively prolonged.

Chronic hepatitis can lead to cirrhosis and hepatocellular carcinoma.

Other complications include: pancreatitis (inflammation of the pancreas), myocarditis (inflammation of heart muscle), atypical pneumonia (an acute respiratory disease marked by high fever and coughing), aplastic anemia (an anemia caused by deficient red blood cell production by the bone marrow), transverse myelitis (An acute attack of inflammatory demyelination that involves both sides of the spinal cord. The spinal cord loses its ability to transmit nerve impulses up and down. Paralysis and numbness are experienced in the legs and trunk below the level of the inflammation.), peripheral neuropathy (a condition of the nervous system that usually begins in the hands and/or feet with symptoms of numbness, tingling, burning and/or weakness).