Hepatitis is an inflammation of the liver usually caused by viral infection, but which may also develop from a number of other causes including parasites, bacteria, toxic agents, various drugs, and alcoholism. Occasionally, hepatitis may also be the result of an autoimmune dysfunction that leads the body to attack the cells of the liver as if they were a foreign substance.

A number of different viruses may instigate hepatitis including Epstein-Barr virus, cytomegalovirus, yellow-fever virus, and seven hepatitis viruses that are only designated alphabetically as hepatitis A, B, C, D, E, F, and G. No matter which virus is responsible for the development of hepatitis, the symptoms are generally the same: abdominal pain, nausea, vomiting, fatigue, fever, and decreased appetite. Some individuals may also experience pain in their joints, a rash, or jaundice, a yellowish discoloration of the eyes, skin, and mucous membranes.

The means of hepatitis transmission varies depending upon the virus responsible for the inflammation. The hepatitis viruses A, E, and F are predominantly spread via the fecal-oral route through food or water that has been contaminated. These viruses are primarily responsible for epidemics of hepatitis in many less-developed regions of the world where crowded conditions and inadequate sanitation are often problems. The other main hepatitis viruses, B, C, D, and G, are chiefly spread through bodily fluids or blood, making their transmission through sexual activity and accidental contact with infected blood a common occurrence.

The most widespread form of hepatitis in the world is caused by the hepatitis A virus. Fortunately, this form of the disease typically requires only bed rest in order for affected individuals to fully recover. Also, vaccines are available and injections of serum globulin derived from other individuals previously infected with hepatitis A can be used as a means of passive immunization to lessen the severity of symptoms in persons that were recently exposed to the virus. Hepatitis viruses B, C, and D, however, are much more serious occurrences that can develop into chronic illnesses and eventually lead to irreversible damage to the liver.

In the United States, approximately 35,000 people become infected with hepatitis C each year, making it the most common blood-borne disease in the country. The primary treatment for hepatitis C is a combination therapy of alpha interferon and the drug ribavirin, though only about half of the patients that receive the treatment experience improvement in their condition. Also, a number of notable side effects, including fatigue, nausea, vomiting, headaches, muscle soreness, depression, irritability, mood swings, insomnia, hair loss, fever, and chest pain, among others, often occur with this form of treatment. However, the risk of death from hepatitis C is such a serious concern (approximately 8,000 to 10,000 Americans die from the disease annually) that most individuals are willing to incur the side effects of treatment. If therapy fails, there is little recourse for patients except for liver transplantation.

Hepatitis at 20x Magnification - Blood transfusions were widely responsible for the transmission of the blood-borne varieties of hepatitis until adequate screening measures were introduced in the 1970s. Similarly, the launch of needle-exchange programs has helped decrease transmission of hepatitis among intravenous dug users.

Hepatitis at 40x Magnification - Hepatitis C, the form of hepatitis most commonly associated with alcoholism, is a particularly virulent variety of the disease that may culminate in cirrhosis of the liver, especially among individuals who continue to drink following diagnosis.

Hepatitis at 10x Magnification - No vaccine is currently available for hepatitis C, but individuals that are infected with the disease are usually advised to receive vaccinations for hepatitis A and B, since their symptoms may become even more severe if they are exposed to another form of the hepatitis virus.