>Hepatitis B -- formerly called serum hepatitis, it is the most common form of hepatitis, with 300 million carriers in the world and an estimated 1.2 million carriers in the United States.
>Hepatitis C -- formerly called non-A, non-B hepatitis. More than 3.9 million Americans are carriers of the virus.
>Hepatitis D -- formerly called delta hepatitis, is found mainly in intravenous drug users who are carriers of the hepatitis B virus, which is necessary for the hepatitis D virus to spread.
>Hepatitis E -- formerly called enteric or epidemic non-A, non-B hepatitis, its symptoms resemble those of hepatitis A. It is caused by a virus commonly found in the Indian Ocean area, Africa and in underdeveloped countries.
>Little is known of the three and possibly five other viruses identified recently. Other viruses, especially members of the herpes virus family, including the cold sore virus, chicken pox virus, infectious mononucleosis virus (EBV) and others can affect the liver.
>Non-viral forms of hepatitis can be caused by drugs or chemicals, such as alcohol, or autoimmune processes. Alcoholic hepatitis is slow in onset but often fatal and cannot be reversed except by transplantation. Some parasites and bacteria can also cause hepatitis as a secondary effect.
>About 26,000 Americans die each year from chronic liver diseases and cirrhosis. Deaths from liver and gallbladder diseases in 1993 reached 51,532, making hepatitis the seventh leading disease that causes death. It is estimated that approximately 75 to 80 percent of cirrhosis cases could be prevented by eliminating alcohol abuse.
>In 1994, an estimated 33,200 people were infected with hepatitis C virus (HCV). There are an estimated 3.9 million people chronically infected with hepatitis C, and about 12,000 die from it each year. The CDC (Centers for Disease Control and Prevention) estimate that annual deaths from hepatitis C will increase to 38,000 by 2010. Hepatitis B is responsible for 5,000 deaths annually: 3,000 to 4,000 from cirrhosis, 1,000 to 1,500 from primary liver cancer and 350 to 450 from fulminant, or severe, hepatitis.
>Fitness and Diving: These diseases are serious and have variable infectivity. The fecal-oral or water-borne route can spread only hepatitis A and E. The oral route may transmit hepatitis B: the virus may be excreted in saliva. The most common symptoms are fatigue, mild fever, muscle or joint aches, nausea, vomiting, loss of appetite, vague abdominal pain and sometimes diarrhea. Many cases go undiagnosed because the symptoms suggest a flu-like illness or may be very mild or absent. As a result, individuals with acute or chronic active hepatitis should not dive.
>Medication Used in Treatment: Until recently, there has been no way to treat hepatitis viral infection. Interferon alpha-2b produces a remission of the disease in 30-40 percent of persons with chronic hepatitis B and 20-25 percent of those infected with chronic hepatitis C. However, once individuals stop taking the drug, 50 to 80 percent of them will suffer a relapse. Only 10 percent of hepatitis B cases are cleared of the virus.
>For treatment of hepatitis C, another drug, ribavirin, is currently pending with the Food and Drug Administration. However, several available vaccines can prevent hepatitis B. They are all safe and effective, and they seem to prevent infection if begun within a few days of exposure.
>Some types of cirrhosis can be treated, but often there is no cure. At this point, treatment is mostly supportive and may include a strict diet, diuretics, vitamins and abstinence from alcohol.
>Additional Information: The following websites have excellent information from which this summary was made, notably: