Hepatitis
Hepatitis implies injury to the liver characterized by the presence of inflammatory cells in the tissue of the organ. The name is from ancient Greek hepar, meaning liver. The condition can be self-limiting, healing on its own, or can progress to scarring of the liver. Hepatitis is acute when it lasts less than six months and chronic when it persists longer. A group of viruses known as the hepatitis viruses cause most cases of liver damage worldwide. Hepatitis can also be due to toxins (notably alcohol), other infections or from autoimmune process. It may run a subclinical course when the affected person may not feel ill. The patient becomes unwell and symptomatic when the disease impairs liver functions that include, among other things, removal of harmful substances, regulation of blood composition, and production of bile to help digestion.
The commonest forms of viral hepatitis are known as hepatitis A, hepatitis B, and hepatitis C; all three of these are caused by viruses that can be transmitted sexually, by blood transfusion, or by shared syringes (see needle-exchange programme).
Hepatitis A (which is often a milder form of this disease), is frequently transmitted by contaminated food, or other forms of fecal-oral contamination.
Hepatitis B more often involves transmission by exposure to blood or other body fluids. About 1 million people die worldwide as a result of hepatitis B, often either of liver failure or liver cancer.
Two other viruses are known, hepatitis D and E, but considered as "additional" complications for types B and C.
Another kind of hepatitis, hepatitis G, has also been identified.
Other viruses, such as cytomegalovirus and Epstein-Barr virus, can also cause infectious hepatitis.
Hepatitis C infection can exist undetected for periods as long as 10 to 20 years, and researchers estimate that millions of people are infected and have not yet displayed any symptoms.
ALPHABETICAL INDEX OF ALL FILES