hich hepatitis, is the most widespread cause of
hich are so deadly to the point where there is no cure for the disease. At one’s first thought, most would think of AIDS, herpes, or maybe alshimers. However one might not consider Hepatitis, because a vaccine has been developed for types of the disease. Hepatitis can be caught and can also be hereditary. It is a disease to which there is no cure for but can be contained. A person may have hepatitis for many years and still not be aware that they have it. The disease can exist in many different forms. Hepatitis is a disorder which involves the inflammation of the liver, the organ in the digestive system which detoxifies harmful substances such as alcohol. Symptoms of hepatitis include loss of appetite, dark urine, fatigue, and sometimes fever. The liver may become enlarged and a disorder called jaundice may occur, giving the skin a yellow tinge. Jaundice is a disorder symptomatic of several liver and blood diseases and is characterized by yellowing of the skin and mucous membranes, particularly the white of the eyes. Hepatogenous jaundice is caused by liver damage, particularly hepatitis. Hepatitis exists in an acute and/or chronic form. The acute form may subside after about two months or, rarely, can result in liver failutre. Chronic carriers are at risk of lasting liver disease. There are many different kinds of Hepatitis, some more serious then others.
Hepatitis A, once called infectious hepatitis, is the most widespread cause of acute hepatitis. Usually transmitted by food and water contaminated by human waste, such infections can reach epidemic proportions in unsanitary and filthy regions. In the United States, increasing members of drug abusers are coming down with Hepatitis A.
Both Hepatitis B and hepatitis non-A, non-B are spread mainly by blood or blood products, and type B is also known to be transmitted from a mother to a fetus and intimate contact, including sexual intercourse. Type B virus is resistant to sterilization of instruments in hospitals, and it is also recurrently seen in drug addicts who have shared needles. It often causes an initial episode of liver disease, unlike non-A, non-B, but both forms occasionally lead to chronic hepatitis. Researchers did not isolate a non-A, non-B virus until the year 1988. The virus they found, labeled C, probably is the cause of all the cases of non-A, non-B hepatitis.
Another form of hepatitis, called delta hepatitis, is caused by a very small virus that cannot replicate on its own. Instead it requires the presence of the hepatitis B virus. First identified in 1977, the virus has since been characterized and labeled as a retrovirus. Delta hepatitis can also become chronic.
A retrovirus is a virus that reproduces itself in a manner distinct from that of most other viruses. The core of any virus is a single molecule of nucleic acid, either DNA or RNA. When a virus invades a cell, this genetic material is usually replicated in its orignial form. A number of RNA viruses, however, make a facsimile of their genetic material in the form of DNA instead. In order to do so, they must be able to produce a particular enzyme that can construct a DNA molecule using an RNA template. This enzyme, called RNA-directed DNA polymerase, is also called reverse transcriptase because it reverse the normal celluar process of transcription. An RNA virus whose life cycle involves the process of reverse transcription is called a retrovirus, which causes Delta Hepatitis.
Acute hepatitis may arise secondary to various infections that involve the liver. It can also occur through ingestion of carbon tetrochloride, the poisonous mushroom Amanita phalloides, arsenic, and certain drugs, including sulfonamides. Mild hepatitis can be caused by two forms of Herpes virus, cytomegalovirus and Epstein-Barr virus.
Mild causes of acute hepatitis are treated with bed rest, however no drug therapy is administered. In forms involving extensive liver damage, blood-exchange transfussion might by imperative. Chronic hepatits lead to cirrhosis and liver damage. Type B virus and certain drugs cause a small percentage of cases, but the cause of most occurrences is unknown. Delta virus may be responsible for some of the relapses observed in patients with chronic active hepatitis. Type B infections have also been linked with a form of liver cancer called hepatocelluar carcinoma, particularly in Asia and Africa. Of those contracting chronic hepatitis, most are women under the age of 45. Steroids are used to treat certain cases of chornic hepatits of nonviral origin, but their prolonged use in treating Hepatitis B is not effective and may even spped of lvier damage. Tests of a newer treatment that combines the uses of steroids with alpha Interferon, however, are showing promise of greater ef!
fectiveness. Alpha interferon has been approved for therapeutic use against hairy-cell Leukemia and Alpha inferferon is also being tested against Hepatitis C. It ahs also been found effective against chronic hepatitis B, which mentioned before, is a major cause of liver cancer and cirrhosis.
Beside interferon, many others have since discovered ways to slow down hepatitis, though there is no cure for the disease, it may be contained. In the 1970’s, Baruch S. Blumberg developed a diagnostic test for type B hepatitis, and in 1981 a gene-splicing technique was used successfully to determine certain other viral types. Blumberg is a physician and biochemist who discovered the Hepatitis B antigen and who is a corecipient of the 1976 Nobel Prize for physiology or medicine for his part in “discoveries concerning new mechanisms for the origin and dissemination of infectious diseases.” After studying hepatitis worldwide, Blumberg isolated the antigen in the blood of an Australian aborigine. This work paved the way for programs to screen blood donors as well as later work on hepatitis B vaccines. A plasma-derived vaccine for type B virus was licensed in 1981, and a vaccine gentically engineered from yeast cells was licensed in 1986. Both are costly. A more recent oral !
vaccine genetically engineered from animal cells has shown promise in animal tests and may eventually provide a less expensive alternative to a vaccine for Hepatitis B.
In conclusion, hepatitis is a disease which has more recently been minimized. Scientists have developed vaccines to some types, however no cure is yet discovered or made. Hepatatis is a disease which must be educated to all people because of the nature of the disease. One can have hepatitis for a long period of time and not know it. As more people come to understand the disease more and more, people can begin treatment earlier and prolong their lifespan.