HEPATITIS


DEFINITION

Hepatitis is an inflammation of the liver. At least six forms of hepatitis are now recognized. They are referred to as hepatitis A, B, C, D, E, and G. They vary considerably in severity. Some forms are acute (sudden and brief) and others are chronic (long-lasting). Some forms have little or no long-lasting effects. Others can become life-threatening diseases.

DESCRIPTION

The liver is one of the most important organs in the body. It regulates the amount of many chemicals that occur in the blood. It removes substances from the blood that are or may become toxic. A toxin is a poison. The liver changes these substances into less harmful forms. It then converts them into a form that will dissolve in water. In this form, the substances are eliminated from the body. If the liver is damaged, toxic substances may build up in the bloodstream. In the worst cases, these substances can cause serious illness and even death.

Most forms of hepatitis are caused by viruses. The viruses have names similar to those of the diseases they cause. Hepatitis A, for example, is caused by the hepatitis A virus (HAV). Hepatitis B is caused by the hepatitis B virus (HBV), and so on.

Hepatitis A and B have been known for many years. At one time they were called infectious and serum hepatitis, respectively. When hepatitis C was first discovered, it was called non-A, non-B hepatitis. It is now known by its simpler name. Hepatitis D, E, and G were discovered during the 1970s, 1980s, and 1990s.

Hepatitis A

Hepatitis A is an acute disorder. An acute disorder is one that comes on suddenly and usually does not last very long. An initial episode of hepatitis A is often followed by a relapse a few weeks later. A relapse is a reoccurrence of the disease. A few people have many relapses.

Children are more likely to contract (catch) hepatitis A than adults, but their symptoms are usually much milder than those of adults.

Among those at highest risk for hepatitis A are the following:

  • Children who go to day-care centers.
  • Troops living under crowded conditions at military camps or in the field.
  • Anyone living in heavily populated and unsanitary conditions.
  • Individuals who practice oral-anal sexual contact.
  • Tourists visiting an area where hepatitis A is common.

Hepatitis: Words to Know

Acute:
A disorder that comes on suddenly and usually does not last very long.
Antibodies:
Chemicals produced by the immune system to destroy invading organisms.
Antigen:
Any particles or portion of an organism that can cause an immune response.
Carrier:
A person whose body contains the organisms that cause a disease but who does not show symptoms of that disease.
Chronic:
A disorder that develops gradually and may last for many years.
Cirrhosis:
A liver disorder caused by scarring of liver tissue.
Hemophilia:
A disorder characterized by the body's inability to clot blood effectively.
Immune system:
A network of organs, tissues, cells, and chemicals designed to protect the body against foreign invaders, such as bacteria and viruses.
Jaundice:
A yellowing of the skin, often caused by a disorder of the liver.
Relapse:
A reoccurrence of a disease.
Toxin:
A poison.

Hepatitis B

Hepatitis B is one of the most common infectious diseases in the world. By some estimates, more than 300 million people worldwide have the disease.

Hepatitis B occurs in both acute and chronic forms. The chronic form is one that develops slowly and remains in the body for a long time. The disease may range from mild to severe. Many people infected with HBV never develop any symptoms. They may not know they have the virus in their bodies, but they are still able to pass the virus on to other people. Such people are said to be carriers of the disease. About 1.5 million Americans are thought to be carriers of HBV.

In its most serious forms, hepatitis B can be a life-threatening disease. The virus causes severe scarring of the liver. The scarring process is called cirrhosis (pronounced suh-RO-suss) of the liver. Cirrhosis damages the liver so badly that it may no longer be able to function normally. It can cause the death of the patient. Cirrhosis can also lead to liver cancer (see cancer entry).

There are three major ways in which hepatitis B can be transmitted. They are:

  • During birth, when a mother with hepatitis B passes HBV to her infant.
  • Coming into contact with infected blood, as happens when a health worker is stuck with a needle containing infected blood.
  • Through sexual contact, especially when such contact results in a tearing of body tissue.

OTHER FORMS OF HEPATITIS

Two other forms of hepatitis are alcoholic hepatitis and autoimmune hepatitis. Both of these disorders result in damage to the liver. They have symptoms similar to those of hepatitis A, B, C, D, E, and G, but they have different causes.

Alcoholic hepatitis is caused by an excessive consumption of alcohol over a period of time. Alcohol is largely broken down in the liver. The more alcohol a person drinks, the harder the liver has to work. In some cases, the liver can be damaged by processing too much alcohol. The cure for alcoholic hepatitis is simple: the patient must stop drinking. When the liver has less alcohol to deal with, it may return to its normal condition.

Some alcoholics find it difficult to give up drinking. In such cases, they can cause severe damage to their livers. They may develop cirrhosis and/or liver cancer. These diseases are major causes of death among alcoholics.

Autoimmune hepatitis occurs when the body's immune system becomes confused. It begins to attack the cells in its own body the way it attacks foreign invaders. Antibodies released by the immune system may attack the liver and cause inflammation.

Autoimmune hepatitis can be acute or chronic. Unfortunately, there is no way to cure the disease. Some people eventually recover from the condition, while others become so ill that they die.

Hepatitis C

Hepatitis C was first identified in 1974. The virus that causes the disease was not found until 1989. The infection is sometimes called "transfusion hepatitis." The name comes from one possible cause of the disease. It may be transmitted along with blood used in blood transfusions. Since the identification of HCV, tests have been developed to identify the virus. Blood transfusions are no longer a major cause of the disease.

Other ways in which the virus can be transmitted include:

  • Through a break in the skin or the inner lining of the mouth or genitals
  • From an infected mother to her child
  • As a result of sexual intercourse

Hepatitis C can occur in either acute or chronic forms. In its acute form, it is quite mild, but in its chronic form it can be even more dangerous than hepatitis B.

Among those at highest risk for hepatitis C are:

  • Health care workers who may come into contact with infected blood
  • Intravenous drug users (people who inject drugs directly into their veins)
  • Individuals who have their skin pierced with a dirty needle while getting tattooed or pierced
  • Hemophiliacs, people with a genetic blood disorder known as hemophilia (see hemophilia entry)
  • Kidney dialysis patients who spend time on machines that cleanse their blood for them

Hepatitis D, E, and G are relatively less common. They may occur in conjunction with one of the other forms of hepatitis or on their own.

CAUSES

The exact mechanism by which viruses cause hepatitis is not entirely understood. It appears that the disease is not caused by the virus itself, but by the body's immune system. The immune system is a network of organs, tissues, cells, and chemicals designed to protect the body against foreign invaders, such as bacteria and viruses.

When a foreign invader enters the body, the immune system begins to respond. It produces chemicals designed to kill the invader. These chemicals are called antibodies. The presence of antibodies in the bloodstream may have other effects on the body, including inflammation, swelling, and other symptoms. It appears that the liver becomes inflamed because of the antibodies produced by the immune system, not because of the virus itself.

SYMPTOMS

The symptoms of the various forms of hepatitis are similar. They are caused by damage to the liver. Perhaps the most noticeable symptom is jaundice. Jaundice causes a yellowing of the skin. Other symptoms associated

Hepatitis A virus magnified 225,000 times. (© 1990. Reproduced by permission of Custom Medical Stock.)
Hepatitis A virus magnified 225,000 times. (© 1990. Reproduced by permission of
Custom Medical Stock
.)

with hepatitis include fatigue, general achiness, nausea, mild fever, and loss of appetite. As infection spreads in the liver, the organ becomes enlarged. It may cause pain in the abdomen.

In the case of acute hepatitis, these symptoms tend to disappear within a few months. In a very small percentage of cases, symptoms may become worse. In less than 1 percent of cases, the patient's liver may fail completely. Patients then stand only a 50–50 chance of surviving the disease.

In cases where symptoms last for at least six months, the patient is said to have chronic hepatitis. Symptoms may continue to get worse. But the worst damage that occurs is cirrhosis of the liver. Cirrhosis leads to liver cancer in somewhat less than 10 percent of all cases.

Many people who have been infected with a hepatitis virus show no symptoms at all. In the case of hepatitis B, that number may be as high as 50 percent. Up to three-quarters of all children with hepatitis A never have symptoms of the infection. Although these individuals have no symptoms, they are still carriers of the disease. They can pass the virus on to other individuals.

DIAGNOSIS

The appearance of jaundice is often the first step in diagnosing hepatitis. The change in color of one's skin is so pronounced that most patients seek medical advice when they have that experience.

Confirmation of this diagnosis can be easily obtained with a blood test. A sample of the patient's blood is drawn (taken). The sample is then tested for the presence of viral antigens or viral antibodies. A viral antigen is a part of the virus that causes the body's immune system to react. A viral antibody is the chemical produced by the immune system to destroy the virus. Blood tests for either viral antigens or viral antibodies—or both—are available for all forms of viral hepatitis.

TREATMENT

There is no cure for hepatitis. The only approach of value is for patients to get as much bed rest as possible. They should continue to eat and drink as much as possible, but alcoholic drinks should be avoided.

PROGNOSIS

The prognosis for various forms of hepatitis varies considerably. Most patients with hepatitis A recover completely within a few months. They become immune to HAV and will not contract the disease again. Up to three-quarters of all Americans over the age of fifty have been exposed to HAV.

About 90 percent of patients with hepatitis B will also recover completely. Among the remaining 10 percent, however, serious complications are likely to develop. These complications include cirrhosis of the liver and liver cancer. About 2 percent of all patients with hepatitis B become chronically ill with the disease.

The prognosis for patients with hepatitis C is slightly less promising. About 15 percent will develop cirrhosis of the liver or liver cancer. Many more are likely to develop chronic hepatitis or some other liver-related disorder.

PREVENTION

Vaccines have now been developed for two forms of hepatitis, A and B. These vaccines are recommended for individuals who may be at risk for one

Magnified image of a hepatitis B virus. (© 1994. Reproduced by permission of Custom Medical Stock.)
Magnified image of a hepatitis B virus. (© 1994. Reproduced by permission of
Custom Medical Stock
.)

of these diseases. For example, health care workers and those who plan to travel to areas where hepatitis is common should be vaccinated.

Injections are also available for those who have already been exposed to hepatitis A or B. These injections can be very effective if they are given fairly soon after the exposure has occurred.

Hepatitis infections can also be prevented by following a number of lifestyle suggestions, including:

  • Wash hands often, especially after using the toilet or coming into contact with another person's blood.
  • Intravenous drug users should not share needles with each other.
  • Personal items that can damage the skin, such as razors, nail files, and scissors, should not be shared.
  • Condoms should be used during vaginal, anal, and oral sex.
  • Travelers in undeveloped areas should boil water and thoroughly wash any fresh fruits or vegetables before eating them.

FOR MORE INFORMATION

Books

Everson, Gregory T. and Hedy Weinberg. Living with Hepatitis C: Survivor's Guide. New York: Hatherleigh Press, 1998.

Rosenthal, M. Sara. The Gastrointestinal Sourcebook. Los Angeles: Lowell House, 1997.

Roybal, Beth Ann Petro. Hepatitis C: A Personal Guide to Good Health. Berkeley, CA: Ulysses Press, 1997.

Silverstein, Alvin, Virginia Silverstein, and Robert Silverstein. Hepatitis. Hillside, NJ: Enslow Publishers, Inc., 1994.

Organizations

American Liver Foundation. 1425 Pompton Ave., Cedar Grove, NJ 07009. (800) 223–0179. http://sadieo.ucsf.edu/alf/alffinal/homepagealf.html.

Hepatitis B Foundation. 101 Greenwood Ave., Suite 570, Jenkitown, PA 19046. (214) 884–8786. http://www.hepb.org.

Web sites

HepNet: The Hepatitis Information Network. [Online] http://www.hepnet.com (accessed on February 2, 1998).

King, J. W. Bug Bytes. [Online] http://www.ccm.lsumc.edu/bugbytes (accessed on October 25, 1999).