Hepatitis (hep-a-TY-tis) is inflammation* of the liver, an abnormal condition that harms liver cells. It usually is caused by the hepatitis A, B, or C virus and may be acute* or chronic*, mild or extremely serious. Hepatitis also can be caused by other germs, by toxic chemicals, or by certain medications.

KEYWORDS

for searching the Internet and other reference sources

Cirrhosis

Hepatic necrosis

Inflammation

Jaundice

Liver transplant

* inflammation: (in-fla-MAY-shun) is the body’s reaction to infection or Irritation.

* acute: means sudden, short, and severe,

* chronic: (KRON-ik) means continuing for a long period of time.

What Is Hepatitis?

The liver, a red-brown, wedge-shaped organ in the upper abdomen, is the largest internal organ in the body and performs the widest range of jobs. It gets rid of harmful substances in food, disposes of old blood cells, helps digest fat, produces chemicals to make the blood clot, and makes sure the blood carries the right balance of fat, sugar, and amino (a-ME-no) acids (the building blocks of proteins) to all the cells of the body.

Complex as it is, the liver is also open to a wide range of problems. Many of these fall under the heading “hepatitis,” a general term that means the liver is experiencing inflammation.

Hepatitis can be caused by many things: excessive drinking of alcohol, overdoses or side effects of medication, inhaling of toxic chemicals, or problems with a person’s immune system*. It can also result from infection with a range of microbes.

* immune system: is the body system that fights disease.

Most hepatitis is caused by infection with a hepatitis virus*, usually the hepatitis A, B, or C virus. Each one can cause acute viral hepatitis, an inflammation of the liver that usually lasts 4 to 6 weeks. Typically, people who have acute viral hepatitis feel exhausted, and their skin and the whites of their eyes take on a yellowish tint, a condition called jaundice (JAWN-dis). In rare cases, acute viral hepatitis can develop into a life-threatening illness called fulminant* hepatitis. But usually it is milder, and the person recovers without needing special care. Often, viral hepatitis causes no symptoms at all.

* virus: (VY-rus) is a tiny infectious agent that lacks an independent metabolism (muh-TAB-o-liz-um) and can only reproduce within the cells it infects.

* fulminant: (FUL-mi-nant) means occurring suddenly and with great severity.

Hepatitis B and C, however, can do long-term damage as well. About 75 to 85 percent of people infected with hepatitis C (and 5 to 10 percent of those infected with hepatitis B) cannot fight off the virus. They become infected chronically, meaning the virus remains active in their body for more than 6 months. In most cases, the infection lasts for decades.

Because the liver is large and resilient, it usually keeps working well despite the virus. In fact, most people with chronic hepatitis live a normal life span and do not even realize that they have the infection. But after 10, 20, 30, or more years, some people with chronic infections eventually will have serious liver damage, such as cirrhosis (si-RO-sis), or scarring of the liver. These unlucky people also have a much greater than normal risk of developing a kind of liver cancer* called hepatocellular carcinoma (hep-a-to-SEL-yoo-lar kar-si-NO-ma). Cirrhosis and liver cancer are both serious, often fatal illnesses.

* cancer: is an uncontrolled growth of cells or tissue, the natural (untreated) course of which can be fatal.

In the United States, hepatitis C is second only to alcohol abuse as a cause of liver damage and is the leading reason people get liver transplants*. Hepatitis C is less likely to cause a noticeable acute illness than hepatitis B, so that most people do not know they have it, but it is more likely to lead to a chronic infection.

* transplants: (TRANS-plantz) are organs or tissues from another body used to replace a poorly functioning organ or tissue.

Worldwide, hepatitis C is believed to infect 170 million people, and health officials fear it will cause major public health problems in the future. Yet HCV, as it is called, is not as well-known as many rarer diseases. The virus was not identified until 1988, and much remains to be learned about how it behaves. One of its apparent effects is to make alcohol more toxic to the liver: many people with liver damage from alcohol turn out to have hepatitis C as well.

In addition to hepatitis A, B, and C, scientists have identified three less-common hepatitis viruses:

Hepatitis D acts as hepatitis B’s sidekick. It is found only in people who already have hepatitis B, and it makes their illness worse.
Hepatitis E occurs only in the developing world. It resembles hepatitis A in that it causes only a short-term illness, but it can be more dangerous, especially to pregnant women. It is usually spread through water that has been contaminated by sewage, often after flooding.
Hepatitis G virus was identified in 1996, but it is not clear that it causes any illness.
There is some evidence for a hepatitis F virus as well, but scientists are not sure.

Hepatitis A: How Does It Spread?

Every now and then, local news reports will tell of an outbreak of hepatitis. Often, the announcers will say that people who ate in a certain restaurant or attended a certain nursery school in the last few weeks should consult their doctor to see about preventing infection.

Hepatitis A is the virus that causes that kind of outbreak. Sometimes called infectious hepatitis, it is highly contagious*, but it almost never does permanent damage. In the United States, hepatitis A most commonly is spread in day care centers to young children and their parents. It spreads by what doctors call the “fecal-oral route.” Virus in the feces (stool) of an infected person somehow gets into the mouth of someone else. This can happen if people fail to wash their hands after changing a diaper or using the toilet and then go on to prepare or serve food. Or one toddler may handle another’s cup or pacifier. In addition, sewage that is not treated properly can contaminate water supplies. Shellfish from contaminated waters can spread the virus if eaten raw or undercooked.

* contagious: (kon-TAY-jes) means able to be transmitted from one person to another.

Once people have recovered from hepatitis A, it is over. They are not “carriers” of the virus and cannot infect anyone else.

Hepatitis A: How Is It Prevented?

Good hygiene, including washing hands after using the toilet and before handling food, can prevent hepatitis A.

Vaccination* against hepatitis A also is available. It is recommended for children and adults traveling to developing countries, for children in communities with high rates of hepatitis A, such as among people of Native American ancestry, and for children who live in states with above-average levels of the disease.

* vaccination: (vak-si-NAY-shun) is taking into the body a killed or weakened germ, or a protein made from such a microbe, in order to prevent lessen, or treat a disease.

Once people have been exposed to the virus, infection often can be prevented by an injection of immune globulin (GLOB-yoo-lin), a substance that helps the immune system. But the globulin must be given within two weeks of exposure to the virus.

Hepatitis B and C: How Do They Spread?

Hepatitis B and C are spread chiefly by contact with an infected person’s blood. People with chronic hepatitis B and C are “carriers,” meaning their blood can transmit the virus to others even if they have no symptoms of illness.

In the United States, these viruses spread most commonly when intravenous (in-tra-VEE-nus) drug users share needles. About 90 percent of people who inject illegal drugs are believed to be infected with hepatitis C, for instance.

Accidental needle sticks, a risk to health care workers, can also spread these viruses. So can organ transplants, tattooing, body piercing, and sharing razors, toothbrushes, or other objects that may have small amounts of blood on them.

Transfusions (trans-FEW-zhunz) of infected blood used to be the biggest source of infection. People with hemophilia (he-mo-FIL-e-a), a blood-clotting problem, were especially likely to be infected when they got blood products drawn from large numbers of donors. Today, however, donors and blood in the United States are screened for both hepatitis B and C, and the risk of getting them from a transfusion is extremely low. But anyone who got a transfusion before July 1992 should be tested for hepatitis C.

The U.S. and the World

In the United States, 4 million people (or 1.8 percent of the population) are estimated to have chronic hepatitis C, and 8,000 to 10,000 people a year die of it. An estimated 1 million to 1.5 million people have chronic hepatitis B, and 5,000 to 6,000 people a year die of it.

Worldwide, hepatitis B is more common, with 400 million people infected. In Southeast Asia and sub-Saharan Africa, where chronic hepatitis B is most common, 10 to 25 percent of all people may carry the virus. Hepatocellular carcinoma, the liver cancer linked to chronic hepatitis, is also most common in these areas. Worldwide, an estimated 170 million people have chronic hepatitis C.

In the United States, hepatitis B is most common in young adults (intravenous drug users, health care workers, prison inmates, and people, especially homosexual men, who have sex with many partners).

In developing countries, hepatitis B is most common in infants and young children, who get it from their mothers or within the family. When hepatitis B infects a child, it is much more likely to become chronic. That is why chronic B is more common in Asia and Africa than in the United States.

Hepatitis B is more contagious than hepatitis C. It is also more contagious than HIV, the virus that causes AIDS*. Hepatitis B spreads readily through sexual contact. Women and men, especially homosexual men, who have sex with many partners are at increased risk.

* AIDS: is short for acquired immunodeficiency (im-yoo-no-de-FISH-un-see) syndrome, the disease caused by the human immunodeficiency virus (HIV), In severe cases, it is characterized by the profound weakening of the body’s immune system.

Hepatitis C is less likely to spread through sexual contact, although it is not clear exactly how easily it spreads this way. In several studies of marriages where one partner is infected with hepatitis C, the other partner does not seem to have an increased risk of getting it. But people who have sex with many partners seem to run a greater risk of infection. Women appear more likely to get hepatitis C from men than vice versa.

Hepatitis B, and more rarely hepatitis C, can also spread from infected mothers to newborns.

Finally, in more than 10 percent of hepatitis C cases, there is no obvious source of infection. It is possible that some means of transmission has yet to be identified.

Neither hepatitis B nor C, however, are known to spread through air, water, or food. A person cannot catch them by being near infected people or by hugging, working, going to school, or swimming with infected people.

How Is Hepatitis B Prevented?

A vaccine can prevent hepatitis B. Since 1991, U.S. health officials have recommended that all newborns receive the necessary three injections. All children ages 11 or 12 should be vaccinated if they did not get the shots as babies. This, officials hope, may virtually eliminate the disease in the youngest generation of Americans.

The vaccine is also recommended for everyone at high risk, including health care workers, people who have had sex with multiple partners, and anyone who lives with, has sex with, or takes care of a person who has hepatitis B.

Once a person has been exposed to hepatitis B, speedy treatment with hepatitis B immune globulin (HBIG), coupled with vaccination, sometimes can prevent infection in adults. When mothers have hepatitis B, immediate treatment of their newborns can prevent the babies from developing chronic hepatitis.

For people who have not been vaccinated, hepatitis B can be prevented by not having unprotected sex, using condoms, and not using intravenous drugs.

In addition, people should avoid contact with blood. They should not share razors, toothbrushes, or any items that have even the slightest amount of blood on them. Infected people should cover any wounds they may have and should dispose of or wash any tissues, clothes, or sanitary napkins that may contain their blood.

Hepatitis C: How Is It Prevented?

There is no vaccine for hepatitis C, and there is no reliable treatment after a person is exposed. Prevention consists of not sharing needles, avoiding contact with blood, limiting sexual contact, and using condoms, as with hepatitis B.

What Are the Symptoms of Hepatitis?

Acute hepatitis can cause loss of appetite, nausea, vomiting, fatigue, fever, jaundice, darkening of the urine, abdominal pain, arthritis (ar-THRY-tis; joint pain), and skin rash. Often symptoms are absent or so mild they go unnoticed.

The incubation* period is 15 to 45 days for hepatitis A, 15 to 150 days for hepatitis C, and 50 to 180 days for hepatitis B.

* incubation: (in-ku-BAY-shun) means the period of time between infection and first symptoms.

Chronic hepatitis can cause loss of appetite, tiredness, low-grade fever, and a general sense of “not feeling well” that doctors call malaise (ma-LAZE). Again, there are often no symptoms.

If the illness causes liver damage, additional symptoms can include weakness, weight loss, itching of the skin, enlargement of the spleen*, fluid in the abdomen, and a pattern of red blood vessels showing through the skin.

* spleen: is a large organ in the upper left part of the abdomen that stores and filters blood and also plays a role in making and breaking down blood cells.

In severe cases, massive bleeding can occur in the stomach and the esophagus*, which requires emergency treatment. If the liver is no longer able to remove toxins from food, the brain can be affected, causing drowsiness, confusion, and even coma*.

* esophagus: (e-SOF-a-gus) is the tube connecting the stomach and the throat.

* coma: (KO-ma) is an unconscious state, like a very deep sleep. A person in a coma cannot be awakened and cannot move, see, speak, or hear.

How Is Hepatitis Diagnosed?

Viral hepatitis is diagnosed on the basis of symptoms and several kinds of blood tests. Liver enzyme tests indicate whether the liver is inflamed. If it is, other blood tests can look for specific evidence of hepatitis B or C and can help doctors distinguish between acute and chronic cases.

In chronic cases, doctors may look for liver damage by doing a biopsy (BY-op-see), in which a sample of the liver is removed by a needle through the skin and examined under a microscope.

In many cases, the first hint of hepatitis comes when a routine blood test done for a physical shows signs of abnormalities in the liver. In other cases, a person may try to donate blood and be rejected after his or her blood is tested.

How Is Hepatitis Treated?

For acute hepatitis, there is no specific treatment. In severe cases, people may be hospitalized to get proper fluids, fever control, and nursing care. For chronic viral hepatitis, the main treatment for years has been interferon alpha (in-ter-FEER-on AL-fa), a naturally occurring substance that interferes with the viruses’ ability to reproduce themselves. Treatment requires injections three times a week for at least 6 months and often causes flulike symptoms or more serious side effects. People often relapse after treatment, which does not eliminate the virus completely.

Hepatitis at a Glance
	Hepatitis A	Hepatitis	Hepatitis C	Hepatitis D	Hepatitis E
How is it spread?	Fecal-oral	Blood	Blood	Blood	Fecal-oral
Is there a vaccine to prevent it?	Yes	Yes	No	No	No
Can it become chronic, causing permananent damage?	No	Yes	Yes	Yes	No
Does it spread through food or water?	Yes	No	No	No	Yes
Does it spread through air?	No	No	No	No	No

Hepatitis A Vaccine

The vaccine for hepatitis A is thought to provide protection for at least 20 years, although the protection may last for life. The vaccine is administered in two or three doses during a 6-month interval.

The vaccine was tested in Thailand on children living in an area with a high rate of infection. More than 40,000 children aged 1 to 6 were given the vaccine in two or three doses. The children who received two doses achieved 94 percent protection, and those receiving three doses had almost 100 percent protection. In the cases that did occur, the symptoms were milder and lasted a shorter time.

People who are planning to travel to areas known to have hepatitis A should discuss vaccination with their doctors. Among those who may be candidates for the vaccine are:

Military personnel

Employees of day care centers
Institutional care workers
Laboratory workers who handle live hepatitis A virus
Handlers of primates that may harbor the hepatitis A virus
People living in, or relocating to, areas with a high rate of infection
Residents of communities experiencing a hepatitis A outbreak
People who engage in high-risk sexual activity
Users of injectable street drugs

In recent years, though, research has been yielding some promising new treatments. A drug called lamivudine, which was developed to treat HIV, also appears to be effective in treating chronic hepatitis B. For chronic hepatitis C, a combination of interferon alpha and a drug called ribavirin (ry-ba-VY-rin) seems to be more effective than interferon alone. Several other treatments are being studied.

People with chronic hepatitis need to be monitored closely by doctors, who may want to see them at least once or twice a year. Doctors will do liver enzyme tests to see how well the liver is functioning and may get blood tests, sonograms*, or even liver biopsies to check for cancer.

* sonograms: (SON-o-gramz) are images or records made on a computer using sound waves passing through the body.

In cases of liver cancer or cirrhosis, sometimes the only treatment is a liver transplant, in which a person s damaged liver is replaced with a healthy organ taken from a deceased person. If the person can get a new liver in time, which is not always possible, such transplants usually are successful, although the virus eventually may damage the new liver as well.

Living with Chronic Hepatitis

Most people with chronic hepatitis do fine. They can go to school, play sports, work, have children, and live a life like anyone else’s.

They need to make sure, however, that they do not put any extra stress on their liver. In the view of most experts, that means that they should never drink alcoholic beverages. They should not take any medicines, even common over-the-counter or herbal remedies, unless they specifically are approved by their doctor. They should not use illegal drugs. In most cases, they should be vaccinated against hepatitis A and against hepatitis B, unless they already have it.

As with other chronic illnesses, people with hepatitis often struggle with feelings of grief, worry, and isolation. Some feel a stigma because their illness often is associated with drug abuse, even though there are many other ways of getting it. Because most people know little about hepatitis, friends and even family may have unrealistic fears about catching it and may avoid the infected person. Counseling for the entire family sometimes can help.

The illness and sometimes the treatment can also cause fatigue and depression*. Infected people may need to get help from family and friends, seek treatment for depression, or modify their schedules to take it easier. Many groups now offer advice, support, and solidarity for people with chronic hepatitis.

* depression: (de-PRESH-un) is a mental state characterized by feelings of sadness, despair, and discouragement.

Hepatitis without a Virus

Not all hepatitis is caused by a virus. It can also be caused by toxic chemicals such as carbon tetrachloride, a solvent used in some dry-cleaning fluids, or by some medications.

Many common medications, such as Dilantin (dy-LAN-tin) for epilepsy (EP-i-LEP-see) and isoniazid (i-so-NY-a-zid) for tuberculosis (too-ber-ku-LO-sis), cause hepatitis in a small fraction of the people who take them. But once the drug is stopped, the liver recovers. Life-threatening hepatitis can result, however, if a person accidentally or intentionally takes an overdose of many medicines, including the common over-the-counter pain reliever acetaminophen (a-set-a-MEE-no-fen).

Finally, some people experience a chronic condition called autoimmune hepatitis. In such people, it appears, the body’s immune system attacks its own liver cells. Although treatment with corticosteroids* can improve the condition, it is often fatal unless a liver transplant is performed.

* corticosteroids: (kor-ti-ko-STEER-oids) are medications that are prescribed to reduce inflammation and sometimes to suppress the body’s immune response.

See also

Alcoholism

Cirrhosis of the Liver

Infection

Jaundice

Viral Infections

Resources

Books

Everson, Gregory T., and Hedy Weinberg. Living with Hepatitis C: A Survivor’s Guide, revised edition. New York: Hatherleigh Press, 1999. A clear, detailed, and encouraging book from a doctor who has treated hundreds of hepatitis C patients and a writer who has hepatitis C herself.

Turkington, Carol. Hepatitis C: The Silent Killer. Chicago: Contemporary Books, 1998.

Organizations

U.S. Centers for Disease Control and Prevention (CDC), 1600 Clifton Road N.E., Atlanta, GA 30333. The U.S. government authority for information about infectious and other diseases, the CDC’s Hepatitis Branch has a hotline and posts information about hepatitis at its website. Telephone 888-443-7232 http://www.cdc.gov/ncidod/diseases/hepatitis/index.htm

The World Health Organization (WHO), Avenue Appia 20, 1211 Geneva 27, Switzerland. This group’s website posts a fact sheet about hepatitis. http://www.who.int/emc/diseases/hepatiti/index.html

The Hepatitis Information Network offers a large amount of well-presented information on its website. http://www.hepnet.com

Complete Human Diseases and Conditions

Hepatitis

views updated May 29 2018

Hepatitis

Definition

Hepatitis is inflammation of the liver. Infectious or viral hepatitis is caused by a viral infection. The three most common forms of viral hepatitis recognized to cause liver disease are hepatitis A, hepatitis B, and hepatitis C (previously called hepatitis non-A, non-B). Other recognized types of hepatitis are hepatitis D, hepatitis E, and hepatitis G.

Description

Hepatitis A

Hepatitis A is an inflammation of the liver caused by the hepatitis A virus (HAV). It is usually not very severe, generally starting within two to six weeks after contact with the virus, and lasting no longer than two months.

Hepatitis A is commonly known as infectious hepatitis because it spreads relatively easily from those infected to their close contacts. Once the infection ends, there is no lasting, chronic phase of illness. However, it is not uncommon to have a second episode of symptoms about a month after the first (a relapse).

Epidemics of HAV infection can infect dozens and even hundreds of persons. Major outbreaks of hepatitis A have been linked to infected food handlers contaminating prepared foods. Many types of food also can be infected by sewage containing HAV, and shellfish are a common culprit.

Certain groups have an increased risk of contracting hepatitis A. These include:

children and employees at daycare centers
individuals living in crowded and/or unsanitary conditions
sexually active individuals
tourists visiting an area where hepatitis A is common

Hepatitis B

More than 300 million people throughout the world are infected by the hepatitis B virus (HBV). Hepatitis B occurs in both rapidly developing (acute) and long-lasting (chronic) forms, and is one of the most frequent chronic infectious diseases worldwide. Commonly called "serum hepatitis," hepatitis B ranges from mild to very severe. Some people who are infected by HBV develop no symptoms, but they may carry HBV in their blood and pass the infection on to others. In its chronic form, HBV infection may destroy the liver through a scarring process called cirrhosis .

When a person is infected by HBV, the virus enters the bloodstream and body fluids, and is able to pass through tiny breaks in the skin, mouth, or the genital area. This infection can occur during birth, when a mother with hepatitis B may pass HBV on to her infant. The virus also may be transmitted through contaminated needles and through unprotected sex with an HBV infected individual. Casual contact cannot transmit hepatitis B.

Hepatitis C

Hepatitis C, or HCV, causes a rapidly developing and often long-lasting disease. Spread mainly by contact with infected blood, HCV is the major cause of "transfusion hepatitis," which can develop in patients who are given blood, although, donated blood is regularly tested for hepatitis C as of the early 2000s. The existence of a third hepatitis virus (in addition to the A and B viruses) became clear in 1974, although HCV was first identified in 1989.

Hepatitis C is generally mild in its early, acute stage, but it is much more likely to produce chronic liver disease than hepatitis B. About two of every three persons who are infected by HCV may continue to have the virus in their blood and become carriers who can transmit the infection to others.

The most common way of transmitting hepatitis C is when blood containing the virus enters another person's bloodstream through a break in the skin or the mucosa (inner lining) of the mouth or genitals. HCV may be passed from an infected mother to the infant she is carrying (however, the risk of infection from breast milk is very low). It also can be spread through sexual intercourse, especially if one partner is acutely infected at the time.

Hepatitis D

Hepatitis D (or delta), occurs only in patients who also are infected by the hepatitis B virus. Infection by the hepatitis delta virus (HDV) either occurs at the same time as hepatitis B, or develops later when infection by HBV has entered the chronic stage.

Delta hepatitis can be quite severe, but is seen only in patients already infected with HBV. In the late 1970s Italian physicians discovered that some patients with hepatitis B had another type of infectious agent in their liver cells. Later the new virus, HDV, was confirmed by experimentally infecting chimpanzees. When both viruses are present, acute infection tends to be more serious. Furthermore, patients with both infections are more likely to develop chronic liver disease than those with HBV alone, and, when it occurs, it is more severe.

Hepatitis E

Hepatitis E also is known as epidemic non-A, non-B hepatitis. Like hepatitis A, it is an acute and short-lived illness that sometimes can cause liver failure. HEV, discovered in 1987, is spread by the fecal-oral route. It is present in countries in which human waste has contaminated the drinking water supply. Large outbreaks (epidemics) have occurred in Asian and South American countries where there is poor sanitation. In the United States and Canada no outbreaks have been reported, but persons traveling to a region where it is present may return with HEV.

Hepatitis G

HGV, also called hepatitis GB virus, was first described in early 1996. Little is known about the frequency of HGV infection, the nature of the illness, or how to prevent it. What is known is that transfused blood containing HGV has caused some cases of hepatitis. For this reason, patients with hemophilia and other bleeding conditions who require large amounts of blood or blood products are at risk of constructing hepatitis G. HGV has been identified in 1–2% of blood donors in the United States. Also at risk are patients with kidney disease who undergo hemodialysis treatments, and those who inject intravenous drugs. It is possible that an infected mother can pass on the virus to her newborn infant, or that sexual transmission can occur.

Often patients with hepatitis G are infected at the same time by the hepatitis B or C virus, or both. In about three of every thousand patients with acute viral hepatitis, HGV is the only virus present. There is some indication that patients with hepatitis G may continue to carry the virus in their blood for many years, and so might be a source of infection for others.

Causes & symptoms

Hepatitis A

The time between exposure to HAV and the onset of symptoms ranges from two to seven weeks and averages about one month. The virus is passed in the feces, especially late in the incubation period, before symptoms first appear. The virus can live for several hours on the skin surface, and during this time may be transmitted to others. Infected persons are most contagious starting about a week before symptoms develop, and remain contagious until the time jaundice (yellowing of the skin and/or eyes) is noted.

Often the first symptoms to appear are fatigue , muscle and joint aches, nausea , and a loss of appetite. Lowgrade fever is common, and the liver often enlarges, causing pain or tenderness in the upper right part of the abdomen. Jaundice then develops, typically lasting seven to ten days.

Hepatitis B

In the United States, a majority of acute HBV infections occur in teenagers and young adults. Half of these youth never develop symptoms, and only about 20% of infected patients develop severe symptoms and jaundice. The remaining 30% of patients have only flu-like symptoms and will probably not even be diagnosed as having hepatitis unless certain tests are done. Acute hepatitis B is characterized by loss of appetite, nausea, and pain or tenderness in the right upper part of the abdomen. Compared to patients with hepatitis A or C, those with HBV infection require more bed rest.

An HBV infection lasting longer than six months is said to be chronic. After this time it is much less likely for the infection to disappear. Not all carriers of the virus develop chronic liver disease; in fact, most have no symptoms. However, about one in every four HBV carriers develop cirrhosis. Patients are also likely to have an enlarged liver and spleen. The most serious complication of chronic HBV infection is liver cancer .

Hepatitis C

More than half of all patients who develop hepatitis C have no symptoms or signs of liver disease. Some, however, may have a minor illness with flu-like symptoms. About one in four patients with hepatitis C will develop jaundice, and some patients lose their appetite and frequently feel tired. Patients also may experience nausea.

In most patients, HCV can still be found in the blood six months after the start of acute infection, and these patients are considered carriers. If the virus persists for one year, it is unlikely to disappear completely. About 20% of chronic carriers develop cirrhosis (scarring) of the liver when the virus damages or destroys large numbers of liver cells, which are then replaced by scar tissue. Cirrhosis may develop only after a long period of time—as long as 20 years—has passed. Many patients will not develop cirrhosis and instead have a mild, chronic form of infection called chronic persistent hepatitis.

Hepatitis D

The delta virus is a small and incomplete viral particle. Perhaps this small size is why it cannot cause infection on its own. Its companion virus, HBV, actually forms a covering over the HDV particle. In chronically ill patients (those whose virus persists longer than six months), cirrhosis typically occurs.

When HBV and HDV infections develop at the same time—a condition called coinfection—recovery is the rule. Only 2–5% of patients become chronic carriers (the virus remains in their blood more than six months after infection). It may be that HDV actually keeps HBV from reproducing as rapidly as it would if it were alone, making chronic infection less likely.

When HBV infection occurs first and is followed by HDV infection, the condition is called superinfection. Between one-half and two-thirds of patients with superinfection develop severe acute hepatitis. Once the liver cells contain large numbers of HBV viruses, HDV tends to reproduce more actively. Massive infection and liver failure are more common in superinfection. The risk of liver cancer, however, is no greater than from hepatitis B alone.

As with other forms of hepatitis, the earliest symptoms are nausea, loss of appetite, joint pains, and fatigue. There may be fever and an enlarged liver may cause discomfort or pain in the right upper part of the abdomen. Jaundice may develop later.

Hepatitis E

There are at least two strains of HEV, one found in Asia and another in Mexico. The virus may start dividing in the gastrointestinal tract, but it grows mostly in the liver. After an incubation period of two to eight weeks, infected persons develop jaundice, fever, nausea, a loss of appetite, and discomfort or pain in the right upper part of the abdomen. Most often the illness is mild and disappears within a few weeks with no lasting effects.

Hepatitis E never becomes a chronic illness, but on rare occasions the acute illness damages and destroys so many liver cells that the liver can no longer function. This is called fulminant liver failure, and may end in death. The great majority of patients who recover from acute infection do not continue to carry HEV and cannot pass the infection on to others.

Hepatitis G

Some researchers believe that there may be a group of GB viruses, rather than just one. Others remain doubtful that HGV actually causes illness. If it does, the type of acute or chronic illness that results is not clear. When diagnosed, acute HGV infection has usually been mild and brief. There is no evidence of serious complications, but it is possible that, like other hepatitis viruses, HGV can cause severe liver damage resulting in liver failure. The virus has been identified in as many as 20% of patients with longlasting viral hepatitis, some of whom also have hepatitis C.

Diagnosis

A health care professional will conduct a thorough medical history and physical examination of the patient when hepatitis is suspected. Blood tests for specific antigens and antibodies that are present in the different subtypes of hepatitis will confirm the diagnosis, although these tests cannot detect all types of hepatitis. Liver function tests that measure enzyme levels may also be performed.

Treatment

Once symptoms appear, no antibiotics or other medicines will shorten the course of infectious hepatitis. Patients should rest in bed as needed, follow a healthy diet, and avoid drinking alcohol or taking any medications that could further damage the liver. Any medication that can cause liver damage should be avoided, and non-critical surgery should be postponed.

An herbalist or naturopathic health care professional may recommend a preparation of milk thistle (Silybum marianum ) for the treatment of hepatitis. Milk thistle is thought to promote the growth of new liver cells, and to prevent toxins from penetrating through healthy liver cells by binding itself to the cell membranes. It is frequently prescribed by herbalists for the treatment of cirrhosis, hepatitis, and other liver disorders. A large controlled trial sponsored by the National Center for Complementary and Alternative Medicine (NCCAM) and the National Institutes of health (NIH) on milk thistle's medicinal value in the treatment of hepatitis and liver injury was scheduled to begin in the year 2000. Licorice (Glycyrriza glabra ) may also be used for hepatitis. Its properties include protecting the liver and enhancing the immune system. Extended use of licorice should not be undertaken without medical consultation, since potassium deficiency may result.

Vitamin C may be taken as a nutritional supplement. It has been shown to help diminish acute hepatitis and help prevent hepatitis in hospitalized patients. Liver extracts are effective in liver regeneration, and have been used for over a century. Thymus extracts enhance the immune system, which may help the body fight a hepatitis virus.

A practitioner of Chinese herbal medicine may recommend Fructus Schisandrae Chinensis, which improves liver function; Fructus Citrulli Vulgaris, which helps to expel jaundice; or other herbs for hepatitis symptoms.

Allopathic treatment

A natural body protein, interferon alpha, now can be made in large amounts by genetic engineering, and improves the outlook for many patients who have chronic hepatitis C. The protein can lessen the symptoms of infection and improve liver function. In 2003, a synthetic analogue was added to improve the treatment's effectiveness. Fever and flu-like symptoms are frequent side effects of this treatment. Approximately one-half of patients respond positively to the treatment, although only about 20% receive lasting effects. Several new treatment drugs have been tested and found beneficial in suppressing hepatitis B since early 2003. One of these drugs also helps those patients infected with both hepatitis B and HIV.

When hepatitis destroys most or all of the liver, the only hope may be a liver transplant. However, even when the procedure is successful, disease often recurs and cirrhosis may actually develop more rapidly than before.

Expected results

Hepatitis A

Most patients with acute hepatitis A, even when severe, begin feeling better in two to three weeks, and recover completely in four to eight weeks. After recovering from hepatitis A, a person no longer carries the virus and remains immune for life. In the United States, serious complications are infrequent and deaths are rare. In the United States, as many as 75% of adults over the age of 50 will have blood test evidence of previous hepatitis A.

Hepatitis B

Each year an estimated 150,000 persons in the United States get hepatitis B. More than 10,000 will require hospital care, and as many as 5,000 will die from complications of the infection. About 90% of those infected will have only acute disease. A large majority of these patients will recover within three months. It is the remaining 10% with chronic infection who account for most serious complications and deaths from HBV infection. In the United States, perhaps only 2% of all infected will become chronically ill. People infected with both HIV and hepatitis B are most likely to die than from either disease alone. Even when no symptoms of liver disease develop, chronic carriers remain a threat to others by serving as a source of infection.

Hepatitis C

In roughly one-fifth of patients who develop hepatitis C, the acute infection will subside, and they will recover completely within four to eight weeks and have no later problems. Other patients face two risks: they themselves may develop chronic liver infection and possibly serious complications such as liver cancer, and they will continue carrying the virus and may pass it on to others. The overall risk of developing cirrhosis is about 15% for all patients infected by HCV. Liver failure is less frequent in patients with chronic hepatitis C than it is for those with other forms of hepatitis. In those people who also have AIDS , hepatitis C infection increases the chance for liver cancer.

Hepatitis D

A large majority of patients with coinfection of HBV and HDV recover from an episode of acute hepatitis. However, about two-thirds of patients chronically infected by HDV go on to develop cirrhosis of the liver. If severe liver failure develops, the chance of a patient surviving is no better than 50%. A liver transplant may improve this figure to 70%.

Hepatitis E

In the United States hepatitis E is not a fatal illness, but elsewhere 1–2% of those infected die of advanced liver failure. In pregnant women the death rate is as high as 20%. It is not clear whether having hepatitis E once guarantees against future HEV infection.

Hepatitis G

What little is known about the course of hepatitis G suggests that illness is mild and does not last long. When more patients have been followed up after the acute phase, it will become clear whether HGV can cause severe liver damage.

Prevention

The best way to prevent any form of viral hepatitis is to avoid contact with blood and other body fluids of infected individuals. The use of condoms during sex also is advisable. Travelers should avoid water and ice if unsure of their purity, or they can boil water before drinking it. All foods eaten should be packaged, well cooked, or, in the case of fresh fruit, peeled. Caution should be exercised when getting tattoos or body piercing, since a 2003 report said that only about one-half of tattoo and piercing shops follow the government's guidelines concerning infection control. These practices can pass hepatitis and HIV infection.

There are vaccines available for both hepatitis A and hepatitis B. Individuals in a high-risk group and travelers should be vaccinated for hepatitis A, and much of the general population can be vaccinated for hepatitis B.

Resources

BOOKS

Fauci, Anthony S. et al., eds. Harrison's Principles of Internal Medicine. 14th edition. New York: McGraw Hill, 1998.

PERIODICALS

"Antiviral Effective Against Hepatitis B Virus in HIV-Coinfected." Virus Weekly (January 28, 2003): 16.

Bauer, Jeff. "Co-infection with Hepatitis B and HIV Increases Men's Risks of Death from Liver Disease." RN (March 2003): 97.

Eckler, Jody A. Lambright. "Preventing Hepatitis." Nursing 29, no. 8 (August 1999): 66.

Elliott, William T. "Warfarin Effectively Prevents Venous Thromboembolism (Pharmacology Watch)." Critical Care Alert (April 2003).

"Hepatitis C Drug Launched." Chemist and Druggist (January 25, 2003):24.

"Hepatitis C Virus Presents Risk for Liver Cancer in Adults with AIDS." Cancer Weekly (January 7, 2003):35.

"Some Tattoo, Piercing Shops Still Unsafe." AIDS Weekly (March 24, 2003):23.

ORGANIZATIONS

Hepatitis Foundation International. 30 Sunrise Terrace, Cedar Grove, NJ 07009-1423. (800) 891-0707. Fax: (973) 857-5044. http://www.hepfi.org/.

OTHER

Centers for Disease Control. Hepatitis. http://www.cdc.gov/ncidod/diseases/hepatitis/.

Hep Net: The Hepatitis Information Network. http://www.hepnet.com/.

Paula Ford-Martin

Teresa G. Odle

Gale Encyclopedia of Alternative Medicine Ford-Martin, Paula; Odle, Teresa

Hepatitis

views updated May 14 2018

Hepatitis

Hepatitis A virus

Symptoms and transmission

Prevention and control

Hepatitis B virus

Symptoms and transmission

Prevention and control

Hepatitis C virus

Prevention and control

Hepatitis D virus

Hepatitis E virus

Prevention and control

Hepatitis G virus

Resources

Hepatitis is inflammation of the liver, a potentially life-threatening disease most frequently caused by viral infections but which may also result from liver damage caused by toxic substances such as alcohol and certain drugs.

Hepatitis viruses identified to date occur in five types: hepatitis A (HAV), hepatitis B (HBV), hepatitis C (HCV), hepatitis D (HDV), and hepatitis E (HEV). All types are potentially serious and, because clinical symptoms are similar, positive identification of the infecting strain is possible only through serologic testing (analyzing the clear, fluid portion of the blood). Symptoms may include a generalized feeling of listlessness and fatigue, perhaps including mental depression, nausea, vomiting, lack of appetite, dark urine and pale feces, jaundice (yellowing of the skin), pain in the upper right portion of the abdomen (where the liver is located), and enlargement of both the liver and the spleen. Severe cases of some types of hepatitis can lead to scarring and fibrosis of the liver (cirrhosis), and even to cancer of the liver. Epidemics of liver disease were recorded as long ago as Hippocrates’ time and, despite major advances in diagnosis, treatment, and prevention methods over the past two decades, viral hepatitis remains one of the most serious global health problems facing humans today.

Hepatitis A virus

The incidence and spread of HAV is directly related to poor personal and social hygiene and is a serious problem not only in developing countries where sanitation and water purification standards are poor, but also in developed, industrialized nations—including the United States, where it accounts for 30% of all incidences of clinical hepatitis. Except in 1% to 4% of cases where sudden liver failure may result in death, chronic liver disease and serious liver damage very rarely develop, and “chronic carrier state,” in which infected people with no visible symptoms harbor the virus and transfer the disease to non-infected individuals, never occurs. Also, reinfection seldom develops in recovered HAV patients because the body eventually develops antibodies, cells that provide a natural immunity to the specific virus attacking the host. Although HAV is self-limiting (after time, ends as a result of its own progress), there is no specific treatment once it is contracted.

Symptoms and transmission

Apart from the symptoms described above, HAV commonly produces a medium-grade fever, diarrhea, headaches, and muscle pain. The primary route of HAV transmission is fecal-oral through ingestion of water contaminated with raw sewage, raw or under-cooked shell-fish grown in contaminated water, food contaminated by infected food handlers, and close physical contact with an infected person. Heterosexual and homosexual activities with multiple partners, travel from countries with low incidences to countries with high rates of infected population, and, less frequently, blood transfusions and illicit intravenous drug use also spread infection.

During the infectious stage, large numbers of viruses are eliminated with the stool. Although HAV infection occurs in all age groups, high rates of disease transmission occur in day-care centers and nursery schools where children are not yet toilet trained or able to wash their hands thoroughly after defecating. The disease may then be transmitted to day-care workers and carried home to parents and siblings. In areas of the world where living quarters are extremely crowded and many people live in unhygienic conditions, large outbreaks of HAV threaten people of all ages. Because during the viruses’ incubation period—from 14 to 49 days—no symptoms are observable, and because symptoms seldom develop in young children, particularly those under the age of two, the disease is often unknowingly but readily transmitted before infected people can be isolated.

Prevention and control

A vaccine against HAV is available. It appears to provide good protection, if the first immunization has been received at least four weeks prior to exposure. Two immunizations about six months apart are recommended. High-risk groups who should receive HAV vaccine include childcare workers, military personnel, Alaskan natives, frequent travelers to HAV endemic areas, laboratory technicians where HAV is handled, and people who work with primates. The immunization lasts for at least 20 years.

If someone who is unimmunized is exposed to HAV, or if a traveler cannot wait four weeks prior to departure for an HAV endemic area, then immune globulin may be utilized to avoid infection. Immune globulin is a naturally occurring substance harvested from the plasma in human blood, then injected into an individual exposed to the HAV. Immune globulin prevents disease development in 80% to 90% of cases in clinical trials. It also seems to be effective in reducing the number of cases normally expected after outbreaks in schools and other institutions. As yet, the most effective control mechanisms are public education regarding the importance of improved personal hygiene, which in many instances is as simple as washing hands thoroughly after using the toilet and before handing food, and concerted worldwide efforts to purify water supplies (including rivers and oceans) and improve sanitation methods.

Hepatitis B virus

Acute HBV is the greatest cause of viral hepatitis throughout the world. World Health Organization figures released in 2003 indicate that as many as 2 billion people worldwide have been infected with the HBV and 400 million people are chronic carriers of the disease. Ten to thirty million people each year become infected with HBV, and about one million people die from HBV complications, such as resultant liver cancer or cirrhosis. HBV-related liver cancer deaths are second only to tobacco-related deaths worldwide. Infected children who survive into adulthood may suffer for years from the damage caused to the liver. In the United States alone, as many as 100,000 people become infected with HBV every year and resultant medical costs amount to more than $1 million per day.

If serology (blood) tests detect the presence of HBV six months or more from time of initial diagnosis, the virus is then termed “chronic.” Chronic persistent hepatitis may develop following a severe episode of acute HBV. Within a year or two, however, this type usually runs its course and the patient recovers without serious liver damage. Chronic active hepatitis also may follow a severe attack of acute HBV infection, or it may simply develop almost unnoticed. Unlike persistent hepatitis, the chronic active type usually continues until fatal liver damage occurs. In limited long-term studies of patients with chronic active hepatitis, more than half developed cirrhosis of the liver within two to five years. Fortunately, this type of hepatitis is seldom seen in children. Newer treatments have offered hope for those with chronic HBV; five drugs have received approval to treat adults and two were approved for children, all since 1990.

Symptoms and transmission

Symptoms are similar to those manifested by HAV and may include weight loss, muscle aches, headaches, flulike symptoms, mild temperature elevation, and constipation or diarrhea. By the time jaundice appears, which is often quite noticeable and prolonged in older women, the patient may feel somewhat better overall but the urine becomes dark, stools light or yellowish, the liver and possibly the spleen enlarged and painful, and fluid may accumulate around the abdominal area. Early in the disease’s course, however, symptoms may be very slight or even virtually nonexistent—particularly in children—facilitating infection of others before isolation is implemented.

The incubation period for HBV varies widely— anywhere from four weeks to six months. Primary routes of transmission are blood or blood product transfusion; body fluids such as semen, blood, and saliva (including a bite by an infected human), organ and/or tissue transplants; contaminated needles and syringes in hospitals or clinical settings; contaminated needles or syringes in illegal intravenous drug use; and “vertical” transmission—from mother to baby during pregnancy, birth, or after birth through breast milk. Even though they may not develop symptoms of the disease during childhood, and will remain healthy, almost all infected newborns become “chronic carriers,” capable of spreading the disease. Many of these infected yet apparently healthy children—particularly the males—will develop cirrhosis and liver cancer in adulthood. Where the incidence of the disease is relatively low, the primary mode of transmission appears to be sexual and strongly related to multiple sex partners, particularly in homosexual men. In locations where disease prevalence is high, the most common form of transmission is from mother to infant.

Prevention and control

Controlling HBV infection is a challenging task. In spite of the development of safe and effective vaccines capable of preventing HBV in uninfected individuals, and regardless of programs designed to vaccinate adults in high-risk categories such as male homosexuals, prostitutes, intravenous drug users, health-care workers, and families of people known to be carriers, the disease still remains relatively unchecked, particularly in developing countries.

Although effective vaccines have been available since the mid-1980s, the cost of mass immunization world-wide, and particularly in developing countries, was initially prohibitive, while immunizing high-risk adult populations did little to halt the spread of infection. Authorities now believe the most effective disease control method will be immunization of all babies within the first few weeks following birth. Concerted efforts of researchers and health authorities worldwide, including the formation of an International Task Force for Hepatitis B Immunization are investigating various avenues for providing cost-effective, mass vaccination programs. These include incorporating HBV vaccination into the existing Expanded Program of Immunization controlled by the World Health Organization. Methods of cost containment, storing the vaccine, and distribution to midwives in remote villages (60% of the world’s births occur at home), have been designed and are continually being refined to ultimately attain the goal of universal infant immunization. This will not only drastically decrease the number of babies infected through vertical transmission (which constitutes 40% of all HBV transmission in Asia), preventing them from becoming adult carriers, it provides immunity throughout adulthood.

Finding an effective treatment for those infected with HBV presents a major challenge to researchers—a challenge equal to that posed by any other disease which still remains unconquered. And HBV may present yet another challenge: mutated forms of the virus seem to be developing resistance to the current vaccines, thus finding a way to survive, replicate, and continue its devastating course. Necessary measures in disease control include: education programs aimed at health care workers to prevent accidental HBV transfer—from an infected patient to an uninfected patient, or to themselves; strict controls over testing of blood, blood products, organs, and tissue prior to transfusion or transplantation; and the “passive” immunization with immunoglobulin containing HBV antibodies as soon as possible after exposure to the active virus.

Hepatitis C virus

HCV exists in more than 200 million carriers worldwide. In the United States, there are about four million people who have been infected with HCV, and over three million of these people remain chronically infected.

Not until 1990 were tests available to identify HCV. Research since then has determined that HCV is distributed globally and, like HBV, is implicated in both acute and chronic hepatitis, as well as liver cancer and cirrhosis. Eighty-five percent of all transfusion-related hepatitis is caused by HCV, and mother-baby and sexual transmission are also thought to spread the disease. Symptoms are similar but usually less severe than HBV; however, it results in higher rates of chronic infection and liver disease.

Prevention and control

Control and prevention of HCV is a serious problem. First, infected people may show no overt symptoms and the likelihood that infection will become chronic means that many unsuspecting carriers will transmit the disease. Second, HCV infection does not appear to stimulate the development of antibodies, which not only means infected people often become reinfected, it creates a major challenge in the development of an effective vaccine. Third, HCV exists in the same general high-risk populations, as does HBV. Combined, these factors make reducing the spread of infection extremely difficult. On a positive note, the development of accurate blood screening for HCV has almost completely eliminated transfusion-related spread of hepatitis in developed countries. Immunoglobulin injections do not protect people who have been exposed to HCV; the search is on for an adequate immunization, although this effort is hampered by characteristics of HCV, which include rapid mutation of the virus.

Hepatitis D virus

Because it is a “defective” virus requiring “coinfection” with HBV in order to live and reproduce, HDV alone poses no threat in the spread of viral hepatitis. It also poses no threat to people vaccinated against HBV. However, when this extremely infectious and potent virus is contracted by unsuspecting carriers of HBV, rapidly developing chronic and even fatal hepatitis often follows. The coexistent requirements of HDV as yet remain unclear. Research into development of an effective vaccine is ongoing, and genetic cloning may aid in this effort.

Hepatitis E virus

Undiscovered until 1980, HEV is transmitted in a similar fashion to HAV. HEV is most prevalent in India, Asia, Africa, and Central America. Contaminated water supplies, conditions that predispose to poor hygiene (as in developing countries), and travel to developing countries all contribute to the spread of HEV. Symptoms are similar to other hepatitis viruses and, like HAV, it is usually self-limiting, does not develop into the chronic stage, and seldom causes fatal liver damage. It does seem, however, that a higher percentage of pregnant women (from 10% to 20%) die from HEV than from HAV.

Prevention and control

Research into the virus was slow because of the limited amounts that could be isolated and collected

KEY TERMS

Carrier —An individual who has a particular bacteria present within his/her body, and can pass this bacteria on to others, but who displays no symptoms of infection.

Coinfection —Infecting together requiring at least one other infectious organism for infection.

Self-limiting —Runs its course, ends or dies out as a result of its own progress.

from both naturally infected humans and experimentally infected primates. Recently, successful genetic cloning (duplication of genes) is greatly enhancing research efforts. Surprisingly, research found that antibodies exist in between 1% and 5% of people who have never been infected with hepatitis. Until an effective vaccine is developed, sanitation remains the most important factor in preventing the spread of HEV.

Hepatitis G virus

Little is currently known about a relatively recently discovered hepatitis virus, G (the virus that was first identified in the 1990s as Hepatitis F was not confirmed, and was thus purged from the list of Hepatitis viruses). HGV appears to be passed through contaminated blood, as is HCV. In fact, many infections with HVG occur in people already infected with HBV, HCV, or HIV. HGV, however, does not seem to change the disease course in people infected with both HCV and HGV. In cases of isolated HGV infection, little liver injury is noted, and there does not appear to be a risk of chronic liver injury.

See also Epstein-Barr virus; Tuberculosis; Vaccine.

Resources

BOOKS

Bloomberg, Baruk S. Hepatitis B: The Hunt for a Killer Virus. Princeton: Princeton University, 2003.

Everson, Gregory T. Living with Hepatitis C. Long Island City, NY: Hatherliegh, 2006.

OTHER

Centers for Disease Control and Prevention. “Viral Hepatitis.” <http://www.cdc.gov/ncidod/diseases/hepatitis/index.htm.> (accessed November 26, 2006).

Marie L. Thompson

The Gale Encyclopedia of Science Thompson, Marie

Hepatitis B Vaccine

views updated May 08 2018

Hepatitis B vaccine

Definition

The hepatitis B vaccine (HBV or HepB) is an injection that protects children from contracting hepatitis B, a serious disease caused by the hepatitis B virus.

Description

The hepatitis B vaccine consists of a small protein from the surface of the hepatitis B virus called the hepatitis B surface antigen (HBsAg). After vaccination with HBV, the child's immune system recognizes HBsAg as foreign and produces antibodies that attach to the protein (anti-HBs). These specific antibodies remain in the blood. Later, if the child becomes infected with the hepatitis B virus, the antibodies recognize the protein and stimulate the immune system to produce large quantities of specific antibodies that attach to and destroy the virus and prevent the disease.

HBV is usually the first vaccine a child receives, most often before leaving the hospital after birth. The second and third HBV immunizations are administered by the age of 18 months, in conjunction with other routine childhood vaccinations.

Vaccine formulations

The HBsAg in HBVs is referred to as recombinant because it is genetically engineered. The gene encoding the DNA for HBsAg is introduced into common baker's yeast. The yeast is grown in vats in which large amounts of HBsAg are produced. The yeast cells are broken, and the HBsAg is isolated and purified. It is adsorbed into aluminum hydroxide.

Packaged hepatitis B vaccine contains the following:

up to 95 percent HBsAg, with 10 to 40 micrograms of HBsAg per milliliter of vaccine
no more than 5 percent yeast protein
a small amount of aluminum hydroxide (0.5 mg/ml)
very small amounts of other additives to stabilize and preserve the vaccine

Two HBVs are approved for use in the United States. Recombivax HB, manufactured by Merck & Company, is as of 2004 available as a pediatric/adolescent formulation (orange cap) and as an adult formulation (green cap). Engerix-B, made by SmithKline Beecham Biologicals, is as of 2004 available as a pediatric formulation (blue cap) and as an adult formulation (orange cap). In general these HBVs are interchangeable and either or both can be used in an individual immunization series. An HBV derived from the blood serum of people with hepatitis B was as of 2004 no longer produced in the United States.

Dosages

The immune response to HBV varies among individual children. Therefore, the HBV dose should be determined by a medical professional. In general, the recommended doses are as follows:

Newborns: 2.5 to 20 micrograms injected into the anterolateral thigh muscle within seven days of birth or at the first visit to the physician's office, and one month and six months after the first dose, for a total of three doses.
Newborns: 10 to 20 micrograms injected into the thigh muscle within seven days of birth and one month, two months, and 12 months after the first dose, for a total of four doses.
Older child or adolescent: 2.5 to 20 micrograms injected into the deltoid arm muscle, with additional doses one month and six months after the first injection, for a total of three doses.

Safety

Although the vast majority of parents believe that vaccinations are important for their children, the majority of parents are also concerned about the safety of vaccines including HBV. Although controversy over the safety of HBV resulted in congressional hearings in 1999, the National Academy of Science's Institute of Medicine, as well as other authorities, considers HBV to be safe. Repeated studies have found no association between HBV and sudden infant death syndrome (SIDS) or other medical conditions, including neurological or immune system disorders.

Effectiveness

HBV usually is effective in protecting against hepatitis B. (HBV also protects against the related hepatitis D virus, which occurs as a co-infection with hepatitis B and usually results in more severe disease symptoms.) However, the immune response to HBV varies among children, apparently due to genetic variations in individual immune systems. In addition, the following medical conditions may cause children to benefit less from HBV:

stomach pain
cirrhosis (scarring) of the liver
immune system impairment
medical conditions requiring kidney dialysis

The duration of hepatitis B immunity following infant vaccination is not known. A 2004 study found that most low-risk children vaccinated at birth did not have antibodies against hepatitis B in their blood by the time they reached the age of five. Although the majority of these children responded positively to a booster HBV immunization, one-third of them did not respond. Likewise, a 2003 Israeli study found a steady decline in anti-hepatitis-B antibodies over time in children vaccinated as infants. The steepest decline in the antibodies occurred between five and eight years after vaccination.

General use

Hepatitis B in children

The U.S. Centers for Disease Control and Prevention (CDC) estimates that, prior to the launch of the infant HBV immunization program, about 33,000 American children of non-infected mothers acquired hepatitis B by the age of ten. Hepatitis B is a potentially serious disease caused by the hepatitis B virus. It may result in inflammation and damage to the liver. Hepatitis B infection may be without symptoms or with acute or short-lived symptoms that can include:

jaundice (a yellowing of the skin and whites of the eyes)
joint pain
stomach pain
itchy red hives on the skin

The hepatitis B virus is eventually cleared from the bodies of most infected adolescents and adults. Only about 2–6 percent of infected older children and adults develop chronic hepatitis B and can continue to transmit the virus to other people. By contrast 90 percent of infants and 30 percent of young children infected with hepatitis B develop chronic disease: the younger the child, the more likely that a hepatitis B infection will become chronic. The consequences of chronic hepatitis B infection may include:

chronic liver disease
cirrhosis
liver cancer
liver failure

There is no cure for hepatitis B and approximately one-fourth of chronic hepatitis B victims die of cirrhosis or liver cancer, including children who do not survive to young adulthood. Of the approximately 1.25 million Americans with chronic hepatitis B, 20–30 percent were infected as infants or children.

Risk of childhood infection

Those with the highest risk for infection are older adolescents and adults engaging in high-risk behaviors such as drug use and unprotected sex with multiple partners.

Far less common sources of childhood hepatitis B infection include:

breast milk from an infected mother
contact with blood, saliva, tears, or urine from an infected household member
cuts
blood transfusions

However, the following children are at particular risk for hepatitis B infection:

children of immigrants and refugees or children adopted from regions where hepatitis B is endemic, including Asia, Sub-Saharan Africa, the Amazon Basin, Eastern Europe, and the Middle East
Alaskan natives and Pacific Islanders
children living in households with a chronically hepatitis-B-infected person
children living in institutions
children receiving hemodialysis
children receiving certain blood products

Children born to infected mothers

Children of hepatitis B-infected mothers are at a 10–85 percent risk of becoming infected during birth. The CDC estimates that, prior to the infant HBV immunization program, about 12,000 American infants per year were infected by their mothers at birth. In addition, children of hepatitis B-infected mothers are at high risk of becoming infected before the age of five.

Children under the age of five who become infected with hepatitis B are at high risk for chronic infection and severe liver damage and disease later in life, even though initially they may have no symptoms. These infected children have a 90 percent risk of chronic hepatitis B infection and as many as 25 percent of them will die of chronic liver disease as adults. Mothers who have emigrated from countries with high rates of endemic hepatitis B are more likely to be infected.

Mothers with acute or chronic infectious hepatitis B can be identified by a blood test for HBsAg. Children born to mothers who have hepatitis B or whose hepatitis B status is unknown should receive their first HBV dose within 12 hours of birth. The second and third doses are given at two and six months of age. In many parts of the world, vaccine intervention before birth is required to prevent hepatitis B infection and its consequences in newborns.

It is recommended that newborns whose mothers are HBsAg-positive receive hepatitis B immune globulin (HBIG)—a preparation of serum containing high levels of antibodies to hepatitis B—as well as HBV within 12 hours of birth. About 70 percent of these newborns will be protected from chronic hepatitis B. A child's immune response to either hepatitis B infection or to HBV can be measured by a blood test for antibodies to HBsAg (anti-HBs). If a vaccinated child is exposed to hepatitis B, a measure of the anti-HBs in the blood will indicate whether another dose of HBV is required. Infants born to mothers who are HBsAg-positive should be tested for anti-HBs three to nine months following their last dose of vaccine. Their anti-HB levels should be at least 10 milli-international units per milliliter (mIU/ml), indicating that they are immune due to vaccination.

Mass immunization

HBV first became available in the United States in 1982. Between 1979 and 1989, the incidence of acute hepatitis B increased in the United States by 37 percent. There were 200,000–300,000 new infections annually between 1980 and 1991. In 1991 the CDC developed a strategy for eliminating the transmission of hepatitis B via universal childhood vaccination. The World Health Organization also declared the goal of immunizing all infants worldwide.

Nearly all states enacted laws requiring hepatitis B vaccination for enrollment in daycare, schools, and colleges. All these laws include exemptions for medical reasons and most include exemptions for religious reasons; however, only a few states allow exemptions from vaccination on philosophical grounds. Most states do not have laws mandating the screening of pregnant women for HBsAg.

By 2002, 90 percent of American children had been vaccinated against hepatitis B. The number of children carrying the virus was subsequently reduced substantially. Infant death from hepatitis B and the incidence of liver disease in children also decreased significantly. The CDC estimates that in 1998 the vaccine prevented 6,800 infections during birth and 18,700 infections in infants and children up to the age of nine. About 12,900 of these children would have developed chronic hepatitis and 3,000 of them eventually would have died of cirrhosis or liver cancer. The CDC expects the overall incidence of hepatitis B in the American population to fall throughout the early 2000s as a result of mass childhood vaccination. However, as of 2004, infants receiving HBV since 1991 had not yet reached the age when high-risk behaviors increase the likelihood of hepatitis B infection. In Pacific Island nations—where rates of hepatitis B infection are among the highest in the world—a regionally coordinated immunization program has significantly reduced the incidence of chronic infection.

Costs

HBV usually is covered by health insurance. In the United States the Vaccines for Children program covers the cost of hepatitis B vaccination for those without health insurance and for other specific groups of children, including Native Americans. The CDC estimates that infant hepatitis B vaccination saves fifty cents in direct medical costs for every dollar spent on HBV.

Precautions

Because most children are not at high risk for hepatitis B infection, and because the duration of immunity provided by HBV is not known, some parents and medical professionals question the need for and the effectiveness of childhood vaccination against hepatitis B. Some also continue to question the safety of the vaccine.

Children should not receive HBV if they are allergic to baker's yeast or thimerosal, are allergic to any other components in a combination vaccine, or have had a previous allergic reaction to HBV. A 2003 study found that HBV was safe and effective in children with asthma , even those on inhaled steroid therapy.

Side effects

Although most children experience no side effects from HBV, the most common side effects are as follows:

fatigue or irritability in up to 20 percent of children
soreness at the point of the injection, lasting one to two days, in about one out of eleven children and adolescents
a mild to moderate fever in one out of 14 children and adolescents

Other less common side effects of HBV include:

a purple spot, hard lump, redness, swelling, pain, or itching at the point of injection
unusual tiredness or weakness
dizziness
fever of 100°F (37.7 °C) or higher
headache

Other rare reactions to HBV include:

general feeling of discomfort or illness
aches or pain in joints or muscles
skin rash or welts that may occur days or weeks after receiving the vaccine
blurred vision or other vision changes
muscle weakness or numbness or tingling in the arms and legs
back pain or stiffness or pain in the neck or shoulder
chills
diarrhea or stomach cramps
nausea or vomiting
increased sweating
sore throat or runny nose
itching
decreased or lost appetite
sudden redness of the skin
swelling of glands in the armpit or neck
difficulty sleeping

Although allergic reactions to HBV are rare, if they occur emergency medical help should be sought immediately. Symptoms of an allergic reaction include:

reddening of the skin, especially around the ears
swelling of the eyes, face, or inside of the nose
hives
itching, especially of the feet or hands
sudden and severe tiredness or weakness
difficulty breathing or swallowing

Parental concerns

Preparing a child for an injection

Most children are afraid of injections; however, there are simple methods for easing a child's fear . Prior to the vaccination parents should take the following steps:

Tell children that they will be getting a shot and that it will feel like a prick; however, it will only sting for a few seconds.
Explain to children that the shot will prevent them from becoming sick.
Have older siblings comfort and reassure a younger child.
Bring along the child's favorite toy or blanket.
Never threaten children by telling them they will get a shot.
Read the vaccination information statement and ask questions of the medical practitioner.

During the vaccination parents should take the following steps:

Hold the child.
Make eye contact with the child and smile.
Talk softly and comfort the child.
Distract the child by pointing out pictures or objects or using a hand puppet.
Sing or tell the child a story.
Have the child tell a story.
Teach the child to focus on something other than the shot.
Help the child take deep breaths.
Allow the child to cry.
Stay calm.

Comforting restraint

Parents may choose to use a comforting restraint method while their child is receiving an injection. These methods enable the parent to control and steady the child's arm while not holding the child down. With infants and toddlers, the following holds may be effective:

The child is held on the parent's lap.
The child's arm is behind the parent's back, held under the parent's arm.
The parent's arm and hand control the child's other arm.
The child's feet are held between the parent's thighs and steadied with the parent's other arm.

With older children, the following positions may be effective:

The child is held on the parent's lap or stands in front of the seated parent.
The parent's arms embrace the child.
The child's legs are between the parent's legs.

After the injection

Following an injection parents should help in the following ways:

Hold and caress a child or breastfeed an infant.
Talk soothingly and reassuringly.
Hug and praise the child for doing well.
Review the information for possible side effects.
Use a cool, wet cloth to reduce soreness or swelling at the injection site.
Check the child for rashes over the following few days.
In addition, parents should remember the following:
The child may eat less during the first 24 hours following a vaccination.
The child should drink plenty of fluids.
The medical practitioner may suggest a non-aspirin pain reliever for the child.

KEY TERMS

Antibody —A special protein made by the body's immune system as a defense against foreign material (bacteria, viruses, etc.) that enters the body. It is uniquely designed to attack and neutralize the specific antigen that triggered the immune response.

Antigen —A substance (usually a protein) identified as foreign by the body's immune system, triggering the release of antibodies as part of the body's immune response.

Booster immunization —An additional dose of a vaccine to maintain immunity to the disease.

Cirrhosis —A chronic degenerative disease of the liver, in which normal cells are replaced by fibrous tissue and normal liver function is disrupted. The most common symptoms are mild jaundice, fluid collection in the tissues, mental confusion, and vomiting of blood. Cirrhosis is associated with portal hypertension and is a major risk factor for the later development of liver cancer. If left untreated, cirrhosis leads to liver failure.

Comvax —Hib-HepB, a combination vaccine that protects against the Haemophilus influenzae type B bacterium and the hepatitis B virus.

Haemophilus influenzae type B —An anaerobic bacteria associated with human respiratory infections, conjunctivitis, and meningitis.

Hepatitis B immune globulin —HBIG, a blood serum preparation containing anti-hepatitis-B antibodies (anti-HBs) that is administered along with HBV to children born to hepatitis-B-infected mothers.

Immunity —Ability to resist the effects of agents, such as bacteria and viruses, that cause disease.

Resources

BOOKS

Atkinson, William, and Charles (Skip) Wolfe, eds. Epidemiology and Prevention of Vaccine-Preventable Diseases, 7th ed. Atlanta, GA: National Immunization Program, Centers for Disease Control and Prevention, 2003.

Blumberg, Baruch S. Hepatitis B: The Hunt for a Killer Virus. Princeton, NJ: Princeton University Press 2003.

Converse, Judy. When Your Doctor Is Wrong: Hepatitis B and Autism. Philadelphia, PA: Xlibris Corp., 2002.

Hepatitis B Vaccine: A Medical Dictionary, Bibliography, and Annotated Research Guide to Internet References. San Diego, CA: Icon Group International, 2004.

PERIODICALS

Petersen, K. M., et al. "Duration of Hepatitis B Immunity in Low Risk Children Receiving Hepatitis B Vaccinations from Birth." The Pediatric Infectious Disease Journal 23 (July 2004): 650–5.

Shouval, D. "Hepatitis B Vaccines." Journal of Hepatology 39 Suppl. 1 (2003): S70–6.

ORGANIZATIONS

Immunization Action Coalition. 1573 Selby Ave., St. Paul, MN 55104. Web site: <www.immunize.org>.

National Immunization Program. NIP Public Inquiries, Mailstop E-05, 1600 Clifton Rd. NE, Atlanta, GA 30333. Web site: <www.cdc.gov/nip>.

National Vaccine Information Center. 421-E Church St., Vienna, VA 22180. Web site: <www.909shot.com>

WEB SITES

"Hepatitis B Facts: Testing and Vaccination." Immunization Action Coalition. Available online at <www.immunize.org/catg.d/p2110.htm> (accessed December 22, 2004).

Margaret Alic, Ph.D.

Gale Encyclopedia of Children's Health: Infancy through Adolescence Alic, Margaret

Hepatitis

views updated May 29 2018

Hepatitis

Definition

The term hepatitis refers to inflammation of the liver caused either by a specific type of virus infection or by non-viral sources. Viral hepatitis is described according to the virus that causes it, including hepatitis A, B, C, D, and E.

Description

An individual with hepatitis has inflammation and enlargement of the liver, and this inflammation interferes with normal liver functions. Important liver functions include removing toxins from the blood, processing and storing nutrients, and producing or repairing blood cells. The liver also manufactures bile, cholesterol, and blood coagulation substances. If the liver does not function, toxins accumulate in the body, causing illness, and nutrient processing is reduced, robbing the body of essential nutritional support.

Clotting of the blood may be reduced, causing uncontrolled bleeding.

Hepatitis can be acute and last about two months, or chronic, lasting from six months to years. The most common forms of viral hepatitis are hepatitisA, B, and C. Hepatitis C often becomes chronic and is a common cause of cirrhosis of the liver and a leading reason for liver transplants. Hepatitis E does not usually occur in the United States. Non-viral forms of hepatitis are related to exposure to toxins, excess alcohol consumption (alcoholic hepatitis), and an autoimmune form that may develop in conjunction with other autoimmune diseases such as rheumatoid arthritis , hemolytic anemia , or a form of kidney disease (glomerulonephritis). Chronic viral and non-viral forms may lead to permanent liver damage and eventual liver failure.

Forms of Hepatitis

Hepatitis A: Commonly called infectious hepatitis, this most common type of viral hepatitis is spread easily by personal contact with an infected person. Transmission is by the fecal-oral route and/or contaminated food. It also occurs in individual cases or national or community-wide epidemics. Hepatitis A virus (HAV) is present in stool and in water that may be contaminated by sewer runoff. People who have hepatitis A do not develop chronic hepatitis and eventually become immune to hepatitis A virus.
Hepatitis B: Called serum hepatitis, this form is spread by contact with hepatitis B virus (HBV) in an infected individual's blood or something that has touched the blood such as syringes or needles, and certain forms of sexual contact. It may also be transmitted from an infected mother to the newborn at birth. Although acute hepatitis B is usually over within weeks, the disease can scar the liver, leading to chronic hepatitis, liver cancer, and liver failure.
Hepatitis C: Spread of hepatitis C requires direct contact with the blood of someone who has hepatitis C virus (HCV) acquired either through blood transfusion, blood-contaminated needles used in injections, intravenous drug use, or from body piercing. The risk is low in acquiring this form of hepatitis from sexual contact or through casual contact. Hepatitis C virus can be present in the body without producing symptoms; it can become chronic before symptoms develop, leading gradually to permanent liver damage, cirrhosis, and liver failure.
Hepatitis D: Hepatitis D virus is a defective virus that causes hepatitis only in the presence of infection with hepatitis b virus. Hepatitis D infection may cause patients with chronic hepatitis B to become more sick.
Hepatitis E: Carried in water, the hepatitis E virus (HEV) is acquired by direct contact in the same way as hepatitis A. It produces epidemics in countries that have open sewers or poor sanitation. Hepatitis E does not typically occur in the United States, but it can could be acquired during foreign travel.
Non-viral hepatitis: Non-viral forms can come from exposure to toxic chemicals that damage the liver such as injectable solutions, drugs and medications, poisons such as arsenic, and chemical substances that can be absorbed through the skin. Non-viral hepatitis also includes alcoholic hepatitis, which develops because of either long-term alcohol consumption or binge drinking, and autoimmune hepatitis developed in conjunction with other autoimmune diseases. Mild forms may not cause considerable liver damage. Severe forms of chronic hepatitis may be treated differently than acute viral forms because of high risk of permanent liver damage. Chronic forms often lead to development of cirrhosis and liver failure.

Demographics

Acute or chronic hepatitis can affect any person, male or female, of any age. Risk of hepatitis A is high among travelers to countries in which the virus is prevalent, among users of injected drugs, homosexual men, and healthcare workers. Hepatitis B affects up to 5% of all Americans, of which 85% are homosexual men. Hepatitis D only occurs in people affected with hepatitis B. Twenty to 40% of all viral hepatitis cases are hepatitis C, primarily occurring in people age 50 or older. The U.S. Centers for Disease Control (CDC) reports that four million people are infected with hepatitis C virus; 2.7 million have chronic infection. At highest risk are people who received blood transfusions before 1992, when U.S. law began to require all donors, units of blood, and blood components to be tested for hepatitis C. Hepatitis E outbreaks are found primarily in younger adults from ages 15 to 40 in countries of southeast Asia, West Africa, and Mexico where fecal-contaminated water is found.

Alcoholic hepatitis can develop at any time past age 20, but typically occurs in people middle-aged or older, and in women twice as often as men due to slower breaking down of alcohol by the body and smaller size of the liver.

Causes and symptoms

Hepatitis A, B, C, D, and E result from infection by an associated virus. Hepatitis A and E require direct contact with an infected individual or anything that has been in contact with the individual's stool, such as bedding, clothing, utensils, or surfaces they have touched. Contaminated food or water can also carry hepatitis A and E viruses . Acquiring hepatitis C requires contact with the blood or body tissues (mucus membrane) of a person already sick with hepatitis; the virus can then remain dormant and produce no symptoms for fifteen years or more. In forms other than hepatitis C, two to eight weeks may pass before hepatitis symptoms develop; this is also the most contagious period. The symptom phase of acute hepatitis may last up to two months. There are other yet poorly understood organisms that may cause infection.

Non-viral forms of chronic hepatitis include alcohol-related hepatitis caused by over-consumption of alcohol, autoimmune hepatitis linked to the presence of other autoimmune diseases, drug-related hepatitis caused by prescription and non-prescriptions drugs (e. g., methyldopa, nitrofurantoid, and acetaminophen ), or exposure to a chemical toxin that has been inhaled, injected, or consumed. In autoimmune hepatitis, the body's immune system becomes overactive and mistakenly attacks the liver. Causes of chronic hepatitis vary, and symptoms may not appear for many years or can occur suddenly and be similar to viral forms.

Characteristic symptoms of hepatitis are similar to flu symptoms, including fever, fatigue, weakness, nausea, vomiting, loss of appetite, abdominal disturbances, diarrhea , and aching muscles and joints. The liver, located under the ribs on the right side of the upper belly, may be painful. Individuals with some forms of hepatitis may eventually have dark urine, yellowish or pale stools, and yellowing of the skin (jaundice). When the liver is more severely affected, the patient may have unexpected bleeding or bruising . People with chronic hepatitis C may have no symptoms at all for years, but typical flu-like symptoms or skin rashes can also appear suddenly.

Diagnosis

The physician will ask about current symptoms, history of other illnesses, use of drugs or alcohol, contact with people known to have hepatitis, recent injections or body punctures for any reason, history of blood transfusions, exposure to chemicals, sexual contact, and travel. Blood tests will be done, especially liver function tests that will indicate liver damage, and serology tests to determine if there is active or chronic hepatitis infection. Exposure to hepatitis C virus may not produce symptoms, and discovery of the antibodies may only happen if the individual is tested when trying to donate blood or during a check-up with blood tests; a home testing kit is available to check for possible exposure to the hepatitis C virus. Ultrasound imaging may be performed to examine the liver. In some cases of suspected acute hepatitis, and nearly always in chronic cases, testing of a tiny sample of liver tissue is required, taking it directly from the liver by needle aspiration through the abdomen (needle biopsy).

Treatment

Most individuals with hepatitis A recover on their own with bed rest, nutritious food, lots of water drunk to flush the body, and avoidance of alcohol or medications that may affect the liver. Hepatitis B is treated similarly and recovery is usually uneventful; oral anti-viral drugs may be given. In the most serious cases, liver transplant may be needed if hepatitis B leads to chronic hepatitis with severe scarring of the liver (cirrhosis). Similar treatment is used for chronic cases of hepatitis C. Primary treatment for chronic non-viral forms of hepatitis is to immediately stop use of causative substance, whether alcohol or drugs. Corticosteroids may be given to reduce inflammation of the liver. In all cases of hepatitis, any complications may need additional treatment. Drugs that reduce immune system activity (immunosuppressants) may be given to those who have autoimmune hepatitis. Liver transplantation may be a treatment option for chronic hepatitis if cirrhosis or liver failure occurs.

Nutrition/Dietetic concerns

A nutritious diet is essential for recovery from viral hepatitis; soft foods such as soup, cream cereals, lightly cooked vegetables, and fruits may appeal most to individuals whose appetite is reduced.

Because poor nutrition can contribute to liver damage, consuming a nutritious diet is important in treating chronic drug-related, alcoholic, or autoimmune hepatitis. Dietary fat intake should be reduced and a doctor, dietician , or nutritionist should be asked about a high-calorie, nutrient-packed diet that will help the liver heal and regenerate.

The herb milk thistle, available in either capsules or tincture, has been shown in clinical studies to protect the liver; it contains silymarin, a bioflavonoid that helps heal and rebuild liver tissue, although it cannot prevent hepatitis after virus exposure. Medicinal licorice root has been shown by researchers to have strong antiviral capabilities and may help reduce severity of hepatitis symptoms. Burdock root is described by certified herbalists as a blood purifier and aid to liver function; it is available in capsule and tincture form.

QUESTIONS TO ASK YOUR DOCTOR

How did I get the hepatitis virus and what type do I have?
What can I do at home to recover from hepatitis?
What can I do to avoid passing the virus to other people?
Will I have any long-term effects from this type of hepatitis?

Prognosis

Approximately 15% of people with hepatitis A recover within weeks; others may have symptoms for six to nine months and then recover without developing chronic hepatitis. Ten percent of people with hepatitis B develop chronic hepatitis that affects the liver permanently, increasing risk of liver cancer . In the United States, hepatitis B is the ninth leading cause of death . Most individuals manage hepatitis C infection and live comfortably, while some may develop chronic hepatitis C leading to permanent liver damage, cirrhosis, liver failure and transplantation, or death. Other chronic forms of hepatitis such as alcoholic hepatitis and autoimmune or drug-related hepatitis are manageable but are subject to permanent liver damage, cirrhosis, liver failure and transplantation, or death, especially if causative drugs or alcohol are not discontinued.

Prevention

A vaccine is available against hepatitis A and B virus, and protection against infection for a short period of time can be gained by receiving immune globulin either before anticipated contact or two weeks after known contact. Vaccines offer the only sure protection against hepatitis A; they are recommended for any senior adult with liver disease or coagulation disorders or travelers to any area known to have high rates or epidemics of hepatitis A. Immune globulin injections offer short-term protection before or after known exposure to hepatitis viruses, especially during travel or care giving for an individual with hepatitis. Because hepatitis A is present in the stool of infected individuals and in water contaminated with run-off from sewage, washing hands frequently with soap and water is essential after bathroom use, when preparing or eating food, and after any contact with someone known to be infected with a hepatitis virus. Sexual contact with a hepatitis virus-infected individual must be avoided or condoms must be used. Bottled or distilled water can be used to avoid use of suspected contaminated water. In countries known to have had prior outbreaks of hepatitis or high likelihood of contaminated water, only cooked food should be consumed, especially vegetables, fruits, and shellfish.

KEY TERMS

Antibodies —Molecules (immunoglobulins) produced by the immune system in response to the presence of a specific molecular trigger (antigen). Specific antibodies found in the blood or body tissues indicates that the corresponding antigen is present in the body.

Aspiration —The process of removing a gas, fluid, or tissue from the body by suction or drainage methods.

Fecal —Pertaining to feces or fecal matter discharged from the bowel.

Immune globulin —A type of amino acid protein present in human serum.

Mucous membrane —Also called mucosa, the thin, moist tissue lining of various organs in the body.

Needle biopsy —The removal of body tissue for examination from a surface or organ. Needle biopsy uses a long needle and syringe device to aspirate (remove by suction) a sample of the target tissue.

For hepatitis B prevention, a vaccine can be used and the hepatitis B immune globulin as soon as possible after potential exposure, such as from a contaminated needlestick.

Prevention of drug-related or alcoholic hepatitis requires abstinence from causative drugs or alcohol. Use of substances known to affect liver function should be reduced or avoided by all adults to prevent possible scarring of the liver or permanent damage to liver function.

Caregiver concerns

Since signs of hepatitis infection are similar in different types of acute viral hepatitis and a specific virus may not have been identified, it is important for caregivers to use all possible precautions to avoid contamination with the hepatitis virus and to protect other people from becoming infected. Careful hygiene is essential, including keeping the sick person's laundry and eating utensils separate, avoiding contact with blood and body fluids as well as stool samples, washing hands frequently before and after caring for the individual and after touching any surface or object that has come in contact with the individual. When the specific virus is identified, physicians may recommend other measures to avoid spreading the infection.

Resources

BOOKS

“Acute Hepatitis.” Merck Manual of Diagnosis and Therapy, Section 16. Edited by R. S. Porter. White House Station, NJ: Merck Research Laboratories, 2007.

“Chronic Hepatitis.” Merck Manual of Diagnosis and Therapy, Section 16. Edited by R. S. Porter. White House Station, NJ: Merck Research Laboratories, 2007.

OTHER

“Alcoholic Hepatitis.” Mayo Foundation for Medical Education and Research. August 15, 2006 [cited March 28, 2008].http://www.mayoclinic.com/health/alcoholichepatitis/DS00785”>

“Autoimmune Hepatitis.” Mayo Foundation for Medical Education and Research. February 28, 2008 [cited March 28, 2008]. http://www.mayoclinic.com/health/autoimmune-hepatitis/DS00676”>

“Hepatitis A: Topic Overview.” WebMD. November 16, 2006 [cited March 28, 2008]. http://www.webmd.com.hepatitis/hepa-guide/”>

“Hepatitis E.” Centers for Disease Control and Prevention. [cited March 28, 2008]. http://www.cdc.gov/ncidod/diseases/hepatitis/e/fact.htm”>

ORGANIZATIONS

American Academy of Family Physicians, 114 Tomahawk Creek Parkway, Leawood, KS, 66211-2672, (800) 274 2237, (913) 906-6269, [email protected], www.familydoctor.org.

Centers for Disease Control, 1600 Clifton Road, Atlanta, GA, 30333, (404) 639-3534, www.cdc.gov.

L. Lee Culvert

The Gale Encyclopedia of Senior Health: A Guide for Seniors and Their Caregivers

Hepatitis

views updated May 14 2018

Hepatitis

Hepatitis is inflammation of the liver, a potentially life-threatening disease most frequently caused by viral infections but which may also result from liver damage caused by toxic substances such as alcohol and certain drugs. Hepatitis viruses identified to date occur in five types: hepatitis A (HAV), hepatitis B (HBV), hepatitis C (HCV), hepatitis D (HDV), and hepatitis E (HEV). All types are potentially serious and, because clinical symptoms are similar, positive identification of the infecting strain is possible only through serologic testing (analyzing the clear, fluid portion of the blood ). Symptoms may include a generalized feeling of listlessness and fatigue, perhaps including mental depression , nausea, vomiting, lack of appetite, dark urine and pale feces, jaundice (yellowing of the skin), pain in the upper right portion of the abdomen (where the liver is located), and enlargement of both the liver and the spleen. Severe cases of some types of hepatitis can lead to scarring and fibrosis of the liver (cirrhosis ), and even to cancer of the liver. Epidemics of liver disease were recorded as long ago as Hippocrates' time and, despite major advances in diagnosis and prevention methods over the past two decades, viral hepatitis remains one of the most serious global health problems facing humans today.

Hepatitis A virus

The incidence and spread of HAV is directly related to poor personal and social hygiene and is a serious problem not only in developing countries where sanitation and water purification standards are poor, but also in developed, industrialized nations—including the United States, where it accounts for 30% of all incidences of clinical hepatitis. Except in 1% to 4% of cases where sudden liver failure may result in death, chronic liver disease and serious liver damage very rarely develop, and "chronic carrier state," in which infected people with no visible symptoms harbor the virus and transfer the disease to non-infected individuals, never occurs. Also, reinfection seldom develops in recovered HAV patients because the body eventually develops antibodies, cells which provide a natural immunity to the specific virus attacking the host. Although HAV is self-limiting (after time, ends as a result of its own progress), there is as yet no effective treatment once it is contracted.

Symptoms and transmission

Apart from the symptoms described above, HAV commonly produces a medium-grade fever, diarrhea, headaches, and muscle pain. The primary route of HAV transmission is fecal-oral through ingestion of water contaminated with raw sewage, raw or undercooked shell-fish grown in contaminated water, food contaminated by infected food handlers, and close physical contact with an infected person. Heterosexual and homosexual activities with multiple partners, travel from countries with low incidences to countries with high rates of infected population, and, less frequently, blood transfusions and illicit intravenous drug use also spread infection .

During the infectious stage, large numbers of viruses are eliminated with the stool. Although HAV infection occurs in all age groups, high rates of disease transmission occur in day-care centers and nursery schools where children are not yet toilet trained or able to wash their hands thoroughly after defecating. The disease may then be transmitted to day-care workers and carried home to parents and siblings. In areas of the world where living quarters are extremely crowded and many people live in unhygienic conditions, large outbreaks of HAV threaten people of all ages. Because during the viruses' incubation period—from 14 to 49 days—no symptoms are observable, and because symptoms seldom develop in young children, particularly those under the age of two, the disease is often unknowingly but readily transmitted before infected people can be isolated.

Prevention and control

A vaccine against HAV is available. It appears to provide good protection, if the first immunization has been received at least four weeks prior to exposure. For adults, two immunizations about six months apart are recommended; for children, three immunizations are necessary (two a month apart, and the third six months later). High-risk groups who should receive HAV vaccine include child care workers, military personnel, Alaskan natives, frequent travelers to HAV endemic areas, laboratory technicians where HAV is handled, and people who work with primates . The immunization lasts for 20 years.

If someone who is unimmunized is exposed to HAV, or if a traveler cannot wait four weeks prior to departure for an HAV endemic area, then immune globulin may be utilized to avoid infection. Immune globulin is a naturally-occurring substance harvested from the plasma in human blood, then injected into an individual exposed to the HAV. Immune globulin prevents disease development in 80% to 90% of cases in clinical trials. It also seems to be effective in reducing the number of cases normally expected after outbreaks in schools and other institutions. As yet, the most effective control mechanisms are public education regarding the importance of improved personal hygiene, which in many instances is as simple as washing hands thoroughly after using the toilet and before handing food, and concerted worldwide efforts to purify water supplies (including rivers and oceans) and improve sanitation methods.

Hepatitis B virus

Acute HBV is the greatest cause of viral hepatitis throughout the world. World Health Organization figures released in 1992 indicate that as many as 350 million people worldwide carry the highly infectious HBV. Because of its severity and often lengthy duration, coupled with the lack of any effective treatment, 40% of those carriers—possibly as many as two million per year—will eventually die from resultant liver cancer or cirrhosis. HBV-related liver cancer deaths are second only to tobacco-related deaths worldwide. Infected children who survive into adulthood may suffer for years from the damage caused to the liver. In the United States alone, as many as 300,000 people become infected with HBV every year, medical costs amount to more than $1 million per day, and the death rate over the last 15 or so years has more than doubled in the U.S.A. and Canada.

If serology tests detect the presence of HBV six months or more from time of initial diagnosis, the virus is then termed "chronic." Chronic persistent hepatitis may develop following a severe episode of acute HBV. Within a year or two, however, this type usually runs its course and the patient recovers without serious liver damage. Chronic active hepatitis also may follow a severe attack of acute HBV infection, or it may simply develop almost unnoticed. Unlike persistent hepatitis, the chronic active type usually continues until fatal liver damage occurs. In long-term studies of 17 patients with chronic active hepatitis, 70% developed cirrhosis of the liver within two to five years. Fortunately, this type of hepatitis is rarely seen in children. Several modes of treatment—including the use of steroids—have been relatively unsuccessful, and treatment with corticosteroids, while appearing at first to have some positive benefit, actually cause additional liver damage.

Symptoms and transmission

Symptoms are similar to those manifested by HAV and may include weight loss, muscle aches, headaches, flu-like symptoms, mild temperature elevation, and constipation or diarrhea. By the time jaundice appears, which is often quite noticeable and prolonged in older women, the patient may feel somewhat better overall but the urine becomes dark, stools light or yellowish, the liver and possibly the spleen enlarged and painful, and fluid may accumulate around the abdominal area. Early in the disease's life, however, symptoms may be very slight or even virtually nonexistent—particularly in children—facilitating infection of others before isolation is implemented.

The incubation period for HBV varies widely—any-where from four weeks to six months. Primary routes of transmission are blood or blood product transfusion; body fluids such as semen, blood, and saliva (including a bite by an infected human); organ and/or tissue transplants; contaminated needles and syringes in hospitals or clinical settings; contaminated needles or syringes in illegal intravenous drug use; and "vertical" transmission-from mother to baby during pregnancy, birth , or after birth through breast milk. Even though they may not develop symptoms of the disease during childhood, and will remain healthy, almost all infected newborns become "chronic carriers," capable of spreading the disease. Many of these infected yet apparently healthy children—particularly the males—will develop cirrhosis and liver cancer in adulthood. Where the incidence of the disease is relatively low, the primary mode of transmission appears to be sexual and strongly related to multiple sex partners, particularly in homosexual men. In locations where disease prevalence is high, the most common form of transmission is from mother to infant.

Prevention and control

Controlling HBV infection is an overwhelming task. In spite of the development of safe and effective vaccines capable of preventing HBV in uninfected individuals, and regardless of programs designed to vaccinate adults in high-risk categories such as male homosexuals, prostitutes, intravenous drug users, health-care workers, and families of people known to be carriers, the disease still remains relatively unchecked, particularly in developing countries.

Although effective vaccines have been available since the mid-1980s, the cost of mass immunization world-wide, and particularly in developing countries, was initially prohibitive, while immunizing high-risk adult populations did little to halt the spread of infection. Authorities now believe the most effective disease control method will be immunization of all babies within the first week following birth. Concerted efforts of researchers and health authorities worldwide, including the foundation in 1986 of an International Task Force for Hepatitis B Immunization are investigating various avenues for providing cost-effective, mass vaccination programs. These include incorporating HBV vaccination into the existing Expanded Program of Immunization controlled by the World Health Organization. Methods of cost containment, storing the vaccine, and distribution to midwives in remote villages (60% of the world's births occur at home), have been designed and are continually being refined to ultimately attain the goal of universal infant immunization. This will not only drastically decrease the number of babies infected through vertical transmission (which constitutes 40% of all HBV transmission in Asia ), preventing them from becoming adult carriers, it provides immunity throughout adulthood.

Finding an effective treatment for those infected with HBV presents a major challenge to researchers—a challenge equal to that posed by any other disease which still remains unconquered. And HBV may present yet another challenge: mutant forms of the virus seem to be developing in resistance to the current vaccines, thus finding a way to survive, replicate and continue its devastating course. Necessary measures in disease control include: education programs aimed at health care workers to prevent accidental HBV transfer—from an infected patient to an uninfected patient, or to themselves; strict controls over testing of blood, blood products, organs, and tissue prior to transfusion or transplantation; and the "passive" immunization with immunoglobulin containing HBV antibodies as soon as possible after exposure to the active virus.

Hepatitis C and E viruses

These relatively recently discovered viruses, often called non-A, non-B hepatitis, exist in more than 100 million carriers worldwide, with 175,000 new cases developing each year in the U.S. and Europe .

Hepatitis C virus

Not until 1990 were tests available to identify HCV. Research since then has determined that HCV is distributed globally and, like HBV, is implicated in both acute and chronic hepatitis, as well as liver cancer and cirrhosis. Eighty-five percent of all transfusion-related hepatitis is caused by HCV, and mother-baby and sexual transmission are also thought to spread the disease. Symptoms are similar but usually less severe than HBV; however, it results in higher rates of chronic infection and liver disease.

Prevention and control

Control and prevention of HCV is a serious problem. First, infected people may show no overt symptoms and the likelihood that infection will become chronic means that many unsuspecting carriers will transmit the disease. Second, HCV infection does not appear to stimulate the development of antibodies, which not only means infected people often become reinfected, it creates a major challenge in the development of an effective vaccine. Third, HCV exists in the same general high-risk populations as does HBV. Combined, these factors make reducing the spread of infection extremely difficult. On a positive note, the development of accurate blood screening for HCV has almost completely eliminated transfusion-related spread of hepatitis in developed countries. Immunoglobulin injections do not protect people who have been exposed to HCV; the search is on for an adequate immunization, although this effort is hampered by characteristics of HCV, which include rapid mutation of the virus.

Hepatitis E virus

Undiscovered until 1980, HEV is believed to transmit in a similar fashion to HAV. HEV is most prevalent in India, Asia, Africa , and Central America. Contaminated water supplies, conditions which predispose to poor hygiene (as in developing countries), and travel to developing countries all contribute to the spread of HEV. Symptoms are similar to other hepatitis viruses and—like HAV—it is usually self-limiting, does not develop into the chronic stage, and seldom causes fatal liver damage. It does seem, however, that a higher percentage of pregnant women (from 10%-20%) die from HEV than from HAV.

Prevention and control

Research into the virus was slow because of the limited amounts which could be isolated and collected from both naturally infected humans and experimentally infected primates. Recently, successful genetic cloning (artificial duplication of genes) is greatly enhancing research efforts. Surprisingly, research found that antibodies exist in between 1%-5% of people who have never been infected with hepatitis. Until an effective vaccine is developed, sanitation remains the most important factor in preventing the spread of HEV.

Hepatitis D virus

Because it is a "defective" virus requiring "coinfection" with HBV in order to live and reproduce, HDV alone poses no threat in the spread of viral hepatitis. It also poses no threat to people vaccinated against HBV. However, when this extremely infectious and potent virus is contracted by unsuspecting carriers of HBV, rapidly developing chronic and even fatal hepatitis often follows. The coexistent requirements of HDV as yet remain unclear. Research into development of an effective vaccine is ongoing, and genetic cloning may aid in this effort.

Hepatitis G virus

Little is currently known about a relatively recently discovered hepatitis virus, G. HGV appears to be passed through contaminated blood, as is HCV. In fact, many infections with HVG occur in people already infected with HCV. HGV, however, does not seem to change the disease course in people infected with both HCV and HGV. In cases of isolated HGV infection, little liver injury is noted, and there does not appear to be a risk of chronic liver injury. Much more information must be sought about this particular hepatitis virus, and its risks.

Resources

books

Kurstak, E. Viral Hepatitis-Current Status and Issues. New York: Springer-Verlag, 1993.

Nishioka, K., et al. Viral Hepatitis and Liver Disease. New York: Springer-Verlag, 1993.

Marie L. Thompson

KEY TERMS

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Carrier: —An individual who has a particular bacteria present within his/her body, and can pass this bacteria on to others, but who displays no symptoms of infection.
Coinfection: —Infecting together requiring at least one other infectious organism for infection.
Self-limiting: —Runs its course, ends or dies out as a result of its own progress.

The Gale Encyclopedia of Science

Hepatitis, Infectious

views updated May 29 2018

Hepatitis, Infectious

What Is Infectious Hepatitis?

Types of Viral Hepatitis

How Common Is Viral Hepatitis?

What Are the Signs and Symptoms of Hepatitis?

How Do Doctors Make the Diagnosis?

What Is the Treatment for Hepatitis?

What to Expect

How Can Hepatitis Be Prevented?

Resources

Hepatitis (heh-puh-TIE-tis) is an inflammation of the liver*. It can have several different causes, most commonly viral infection.

*liver: is a large organ located beneath the ribs on the right side of the body. The liver performs numerous digestive and chemical functions essential for health.

KEYWORDS

for searching the Internet and other reference sources

Alpha-interferon

Cirrhosis

Liver disease

Sexually transmitted diseases

What Is Infectious Hepatitis?

The liver plays many important roles in the body. It filters out toxins* and other harmful substances from the blood, stores vitamins and nutrients, regulates cholesterol* production, and helps in the production of many other substances the body needs to function normally. Long-term drug or alcohol abuse, exposure to harmful chemicals or other toxins, various infections, trauma*, and certain medications all can damage the liver and lead to hepatitis. Viruses usually cause infectious hepatitis, although other organisms, such as bacteria or parasites, sometimes can be the culprit as well.

*toxins: are poisons that harm the body.

*cholesterol: (ko-LES-ter-ol) is a fatlike substance found in the blood and body tissues.

*trauma: is severe injury to the body.

Several different viruses can bring about acute* hepatitis, including at least five known hepatitis viruses (A through E). Among these viruses, hepatitis B (HBV) and C (HCV) cause the most serious disease. Most of the time, people recover fully from viral hepatitis. But in some people HBV and HCV cause chronic* hepatitis, in which the infection remains in the body and the liver does not recover completely from the inflammation. Chronic hepatitis eventually can lead to severe liver damage, liver cancer, and sometimes cirrhosis* of the liver. Other viral infections, such as infectious mononucleosis* or “mono,” which usually is caused by the Epstein-Barr (EP-steen BAR) virus, can produce shortlived, mild hepatitis.

*acute: describes an infection or other illness that comes on suddenly and usually does not last very long.

*chronic: (KRAH-nik) means continuing for a long period of time.

*cirrhosis: (sir-O-sis) is a condition that affects the liver, involving long-term inflammation and scarring, which can lead to problems with liver function.

*mononucleosis: (mah-no-nuklee-O-sis) is an infectious illness caused by a virus that often leads to fever, sore throat, swollen glands, and tiredness.

Types of Viral Hepatitis

Hepatitis A

Among the five major types, hepatitis A virus (HAV) causes the most common and least serious form of hepatitis. It typically spreads through eating food or drinking water contaminated with feces* from someone who is infected. Parts of the world with poor sanitation are at greatest risk for outbreaks of the disease. In the United States, cases of HAV infection sometimes arise when food handlers fail to practice good hygiene, such as regularly washing their hands. HAV also can be transmitted during unprotected sexual intercourse.

*feces: (FEE-seez) is the excreted waste from the gastrointestinal tract.

Hepatitis B

HBV infection can lead to chronic hepatitis in up to 10 percent of infected adults and older children, in up to 30 percent of infected children younger than 6 years old, and in up to 90 percent of infants who contract the virus from their infected mothers at birth. It is a more serious form of hepatitis because it can cause long-term or permanent liver inflammation and scarring, liver cancer, and liver failure.

HBV can pass easily from person to person through direct contact with infected blood and other body fluids, including semen*, vaginal* fluids, and sometimes saliva. It most often is spread through unprotected sexual intercourse, injection of drugs with contaminated needles, blood transfusions*, kidney* dialysis*, organ transplants, or from a mother to her child during birth. HBV also can be transmitted if improperly sterilized equipment is used during body piercing, tattooing, or circumcision*. Health care workers are advised to take precautions to avoid accidental sticks from needles used in the care of patients, because patients might be infected with the virus.

*semen: (SEE-men) is the sperm-containing whitish fluid produced by the male reproductive tract.

*vaginal: (VAH-jih-nul) refers to the vagina, the canal in a woman that leads from the uterus to the outside of the body.

*transfusions: (trans-FYOO-zhunz) are procedures in which blood or certain parts of blood, such as specific cells, are given to a person who needs them because of illness or blood loss.

*kidney: is one of the pair of organs that filter blood and remove waste products and excess water from the body in the form of urine.

*dialysis: (dye-AL-uh-sis) is a process that removes waste, toxins (poisons), and extra fluid from the blood. Usually dialysis is done when a person’s kidneys are unable to perform these functions normally.

*circumcision: is a surgical procedure in which the fold of skin covering the end of the penis is removed.

Hepatitis C

Like HBV, HCV can spread through direct contact with infected body fluids, especially blood. HCV most often is transmitted through the sharing of needles by injection drug users. In the United States, up to 90 percent of cases occur this way. Patients receiving long-term dialysis for kidney failure are also at relatively higher risk of HCV infection. The infection can result in long-lasting complications. About 80 percent of those who contract HCV may develop chronic hepatitis, which can put them at risk for other forms of serious liver disease. HCV infection is the most common reason for liver transplants in the United States.

Hepatitis D

Hepatitis D virus (HDV) infection is found only in those who also have been infected with HBV. HDV is passed from person to person in the same way as HBV. Co-infection can transform a mild HBV infection or an infection that has no symptoms at all into a more serious, rapidly progressing disease. HDV usually spreads through contact with infected blood, most often from injection drug use with contaminated needles.

Hepatitis E

Like HAV, hepatitis E virus (HEV) is transmitted through drinking water contaminated with infected feces. HEV infection occurs most often in underdeveloped countries with poor sanitation.

How Common Is Viral Hepatitis?

Infectious hepatitis is common all over the world. Each year HAV infects up to 1.4 million people worldwide, including about 250,000 Americans. Most cases in the United States are seen in children less than 10 years of age. According to the U.S. Centers for Disease Control and Prevention (CDC), at least 80,000 people in the United States are infected with HBV each year, and about 5,000 die from the disease annually. Africa and parts of South America and Asia, especially the Middle East, all have high rates of HAV and HBV infection. The World Health Organization (WHO) estimates that there are 170 million people infected with HCV around the globe, with 3 million to 4 million new cases appearing annually. About 4 million people in the United States have HCV, with about 25,000 new cases diagnosed each year.

What Are the Signs and Symptoms of Hepatitis?

Common symptoms of all forms of acute infectious hepatitis include extreme tiredness, loss of appetite, fever, headache, muscle and joint aches, nausea, vomiting, diarrhea, jaundice*, and stomach pain. Bowel movements may look pale in color, and urine may become dark, so that it looks like tea. Children infected with HAV frequently have few or no signs of illness, and people with HCV infection often show no symptoms or have only mild symptoms like those of the flu until the disease has caused serious liver damage.

*jaundice: (JON-dis) is a yellowing of the skin, and sometimes the whites of the eyes, caused by a buildup in the body of bilirubin, a chemical produced in and released by the liver. An increase in bilirubin may indicate disease of the liver or certain blood disorders.

How Do Doctors Make the Diagnosis?

Hepatitis is diagnosed by blood tests, which can show that the liver is inflamed and indicate how well it is working. Blood tests can also reveal which type of hepatitis virus is causing the disease. When a person is very ill from hepatitis or remains sick for a long time, a biopsy* of the liver may be done to determine whether the liver is becoming damaged or scarred.

*biopsy: (BI-op-see) is a test in which a small sample of body tissue is removed and examined for signs of disease.

What Is the Treatment for Hepatitis?

Treatment for viral hepatitis depends on its cause and how sick the patient is.

Hepatitis A and E

People with HAV and HEV infection usually recover completely without needing hospitalization. They can take care of themselves at home by making sure they get enough rest and drink plenty of fluids. Doctors advise avoiding alcohol and drugs, because these substances can stress an already inflamed liver.

Hepatitis B and C

Most of the time, HBV and HCV infection can be monitored with blood tests that look for liver inflammation and measure liver function. In severe cases of viral hepatitis, hospitalization may be necessary, especially when the liver is damaged and stops working well. Medications, including alpha-interferon (AL-fa in-ter-FEER-on) injections, may be given to help the body’s immune system fight chronic hepatitis B, C, and D. It is recommended that people who have chronic infectious hepatitis live a healthy lifestyle by avoiding alcohol, getting enough sleep, exercising regularly, and eating a nutritious diet. These measures reduce stress on the liver and can prevent or slow the progression of long-term liver disease.

What to Expect

People typically recover completely from HAV or HEV infection within about 2 months, but sometimes it takes longer. Those infected with HBV or HCV usually recover within 6 months. Cases of chronic viral hepatitis can last for decades or even a lifetime. HBV and HCV can lead to scarring of the liver, liver cancer, liver failure, and sometimes death. A liver transplant may be required in cases that progress to liver failure.

How Can Hepatitis Be Prevented?

A vaccine* exists for HAV, but it is not used routinely in the United States, except in areas where the number of cases is consistently high, as seen in several western states. The vaccine is recommended for certain laboratory workers, anyone who has more than one sexual partner or who engages in other high-risk types of behavior, or people traveling to underdeveloped areas of the world with poor sanitation. People who come into contact with HAV can be treated with immune globulin*, which is more than 85 percent effective in preventing HAV infection if treatment begins within 2 weeks after exposure to the virus. The best way to prevent HAV and HEV is to practice good hygiene, such as frequent hand washing. Avoiding areas of poor sanitation and unwashed or uncooked food, particularly while traveling, can limit the risk of infection as well.

*vaccine: (vak-SEEN) is a preparation of killed or weakened germs, or a part of a germ or product it produces, given to prevent or lessen the severity of the disease that can result if a person is exposed to the germ itself. Use of vaccines for this purpose is called immunization.

*immune globulin: (ih-MYOON GLAH-byoo-lin), also called gamma globulin, is the protein material that contains antibodies.

Today, infants in the United States typically are vaccinated against HBV by age 2 years. Infants born to mothers with HBV infection generally are given immediate injections of HBV immune globulin and receive their first dose of the HBV vaccine within 12 hours of birth. It is recommended that all teens and adults who are at high risk of exposure to infected body fluids, such as health care workers, receive the HBV vaccine. Since HDV infects only those who already have HBV, vaccination against HBV can prevent HDV as well. Using latex condoms for all forms of sexual intercourse also can help protect against HBV. Avoiding intravenous drug use and sharing of razors, toothbrushes, or needles, even for tattoos or body piercing, can help prevent both HBV and HCV. Since 1992 blood banks in the United States have screened donated blood for HBV and HCV. Currently, there is no vaccine for HCV.

See also

Mononucleosis, Infectious

Sexually Transmitted Diseases

Resources

Organizations

American Liver Foundation, 75 Maiden Lane, Suite 603, New York, NY 10038. The American Liver Foundation is a national nonprofit organization dedicated to the prevention, treatment, and cure of hepatitis and other liver diseases. It posts articles on liver health at its website.

Telephone 800-465-4837 http://www.liverfoundation.org

Hepatitis Foundation International, 504 Blick Drive, Silver Spring, MD 20904. The Hepatitis Foundation International offers information on hepatitis at its website, as well as counseling via its toll-free hotline.

Telephone 800-891-0707 http://www.hepfi.org

Website

KidsHealth.org. KidsHealth is a website created by the medical experts of the Nemours Foundation and is devoted to issues of children’s health. It contains articles on a variety of health topics, including hepatitis.

http://www.KidsHealth.org

Complete Human Diseases and Conditions

Hepatitis B

views updated Jun 08 2018

Hepatitis B

Definition

Hepatitis B is a potentially serious form of liver inflammation due to infection by the hepatitis B virus (HBV). It occurs in both rapidly developing (acute) and long-lasting (chronic) forms, and is one of the most common chronic infectious diseases worldwide. An effective vaccine is available that will prevent the disease in those who are later exposed.

Description

Commonly called "serum hepatitis," hepatitis B ranges from mild to severe. Some people who are infected by HBV develop no symptoms and are totally unaware of the fact, but they may carry HBV in their blood and pass the infection on to others. In its chronic form, HBV infection may destroy the liver through a scarring process, called cirrhosis, or it may lead to cancer of the liver.

When a person is infected by HBV, the virus enters the bloodstream and body fluids, and is able to pass through tiny breaks in the skin, mouth, or the male or female genital area. There are several ways of getting the infection:

During birth, a mother with hepatitis B may pass HBV on to her infant.
Contact with infected blood is a common means of transmitting hepatitis B. One way this may happen is by being stuck with a needle. Both health care workers and those who inject drugs into their veins are at risk in this way.
Having sex with a person infected by HBV is an important risk factor (especially anal sex).

Although there are many ways of passing on HBV, the virus actually is not very easily transmitted. There is no need to worry that casual contact, such as shaking hands, will expose one to hepatitis B. There is no reason not to share a workplace or even a restroom with an infected person.

More than 300 million persons throughout the world are infected by HBV. While most who become chronic carriers of the virus live in Asia and Africa, there are no fewer than 1.5 million carriers in the United States. Because carriers represent a constant threat of transmitting the infection, the risk of hepatitis B is always highest where there are many carriers. Such areas are said to be endemic for hepatitis B. When infants or young children living in an endemic area are infected, their chance of becoming a chronic hepatitis B carrier is at least 90%. This probably is because their bodies are not able to make the substances (antibodies) that destroy the virus. In contrast, no more than 5% of infected teenagers and adults develop chronic infection.

Causes and symptoms

With the exception of HBV, all the common viruses that cause hepatitis are known as RNA viruses because they contain ribonucleic acid or RNA as their genetic material. HBV is the only deoxyribonucleic acid or DNA virus that is a major cause of hepatitis. HBV is made up of several fragments, called antigens, that stimulate the body's immune system to produce the antibodies that can neutralize or even destroy the infecting virus. It is, in fact, the immune reaction, not the virus, that seems to cause the liver inflammation.

Acute hepatitis B

In the United States, a majority of acute HBV infections occur in teenagers and young adults. Half of these youth never develop symptoms, and only about 20%—or one in five infected patients—develop severe symptoms and yellowing of the skin (jaundice ). Jaundice occurs when the infected liver is unable to get rid of certain colored substances, or pigments, as it normally does. The remaining 30% of patients have only "flu-like" symptoms and will probably not even be diagnosed as having hepatitis unless certain tests are done.

The most commom symptoms of acute hepatitis B are loss of appetite, nausea, generally feeling poorly, and pain or tenderness in the right upper part of the abdomen (where the liver is located). Compared to patients with hepatitis A or C, those with HBV infection are less able to continue their usual activities and require more time resting in bed.

Occasionally patients with HBV infection will develop joint swelling and pain (arthritis) as well as hives or a skin rash before jaundice appears. The joint symptoms usually last no longer than three to seven days.

Typically the symptoms of acute hepatitis B do not persist longer than two or three months. If they continue for four months, the patient has an abnormally long-lasting acute infection. In a small number of patients—probably fewer than 3%—the infection keeps getting worse as the liver cells die off. Jaundice deepens, and patients may bleed easily when the levels of coagulation factors (normally made by the liver) decrease. Large amounts of fluid collect in the abdomen and beneath the skin (edema ). The least common outcome of acute HBV infection, seen in fewer than 1% of patients, is fulminant hepatitis, when the liver fails entirely. Only about half of these patients can be expected to live.

Chronic hepatitis B

HBV infection lasting longer than six months is said to be chronic. After this time it is much less likely for the infection to disappear. Not all carriers of the virus develop chronic liver disease; in fact, a majority have no symptoms. But, about one in every four HBV carriers develop liver disease that gets worse over time, as the liver becomes more and more scarred and less able to carry out its normal functions. A badly scarred liver is called cirrhosis. Patients are likely to have an enlarged liver and spleen, as well as tiny clusters of abnormal blood vessels in the skin that resemble spiders.

The most serious complication of chronic HBV infection is liver cancer. Worldwide this is the most common cancer to occur in men. Nevertheless, the overall chance that liver cancer will develop at any time in a patient's life is probably much lower than 10%. Patients with chronic hepatitis B who drink or smoke are more likely to develop liver cancer. It is not unusual for a person to simultaneously have both HBV infection and infection by HIV (human immunodeficiency virus, the cause of AIDS ). A study released in 2003 reported that men infected with both HIV and HBV were more likely to die from liver disease than people infected with just one of the diseases.

Diagnosis

Hepatitis B is diagnosed by detecting one of the viral antigens—called hepatitis B surface antigen (HBsAg)—in the blood. Later in the acute disease, HBsAg may no longer be present, in which case a test for antibodies to a different antigen—hepatitis B core antigen—is used. If HBsAg can be detected in the blood for longer than six months, chronic hepatitis B is diagnosed. A number of tests can be done to learn how well, or poorly, the liver is working. They include blood clotting tests and tests for enzymes that are found in abnormally high amounts when any form of hepatitis is present.

Treatment

In the past, there was no treatment available for hepatitis B. But developments have been made in recent years on drugs that suppress the virus and its symptoms. In early 2003, a drug called adefovir was reported as an effective treatment. Another drug called tenofovir was demonstrated as effective in patients infected with both hepatitis B and HIV. Two studies also reported on the effectiveness of a drug called Preveon, which was more expensive than others. Patients also should rest in bed as needed, continue to eat a healthy diet, and avoid alcohol. Any non-critical surgery should be postponed.

Prognosis

Each year an estimated 150,000 persons in the United States get hepatitis B. More than 10,000 will require hospital care, and as many as 5,000 will die from complications of the infection. About 90% of all those infected will have acute disease only. A large majority of these patients will recover within three months. It is the remaining 10%, with chronic infection, who account for most serious complications and deaths from HBV infection. In the United States, perhaps only 2% of all those who are infected will become chronically ill. The course of chronic HBV infection in any particular patient is unpredictable. Some patients who do well at first may later develop serious complications. Even when no symptoms of liver disease develop, chronic carriers remain a threat to others by serving as a source of infection.

Prevention

The best way to prevent any form of viral hepatitis is to avoid contact with blood and other body fluids of infected individuals. The use of condoms during sex also is advisable.

If a person is exposed to hepatitis B, a serum preparation containing a high level of antibody against HBV may prevent infection if given within three to seven days of exposure. Babies born of a mother with HBV should receive the vaccine within 24 hours. An effective and safe vaccine is available that reliably prevents hepatitis B. Vaccination is suggested for most infants and for children aged 10 and younger whose parents are from a place where hepatitis B is common. Teenagers not vaccinated as children and all adults at risk of exposure also should be vaccinated against hepatitis B. Three doses are recommended.

KEY TERMS

Antibody— A substance formed in the body in response to a foreign body, such as a virus, which can then attack and destroy the invading virus.

Antigen— Part of an invading microorganism, such as a virus, that causes tissue damage (in hepatitis, to the liver), and that also stimulates the body's immune system to produce antibodies.

Cirrhosis— The end result of many forms of liver disease, the condition of the liver when its cells have been damaged or destroyed and are replaced by scar tissue.

Vaccine— A substance prepared from a weakened or killed virus which, when injected, helps the body to form antibodies that will attack an invading virus and may prevent infection altogether.

Those at increased risk of getting hepatitis B, and who therefore should be vaccinated, include:

household contacts of a person carrying HBV
healthcare workers who often come in contact with patients' blood or other body fluids

patients with kidney disease who periodically undergo hemodialysis
homosexual men who are sexually active, and heterosexuals who have multiple sex partners
persons coming from areas where HBV infection is a major problem
prisoners and others living in crowded institutions
drug abusers who use needles to inject drugs into their veins

Studies released in 2003 showed increased risk of nonresponse to hepatitis B vaccines among adults over age 30. This may be related to age-associated changes in the immune system.

Resources

PERIODICALS

"Antiviral Effective Against Hepatitis B Virus in HIV-coinfected." Virus Weekly January 28, 2003: 16.

Bauer, Jeff. "Co-infection with Hepatitis B and HIV Increases Men's Risks of Death from Liver Disease." RN March 2003: 97.

Elliott, William T. "Warfarin Effectively Prevents Venous Thromboembolism (Pharmacology Watch)." Critical Care Alert April 2003.

"Hepatitis B Vaccine Loses Effectiveness in Older Adults." Vaccine Weekly January 29, 2003: 23.

ORGANIZATIONS

Hepatitis B Foundation. 101 Greenwood Ave., Suite 570, Jenkintown, PA 19046. (215) 884-8786. 〈[email protected]〉.

Gale Encyclopedia of Medicine, 3rd ed. Cramer, David; Odle, Teresa

Hepatitis A

views updated May 09 2018

Hepatitis A

Definition

Hepatitis A is a liver disease caused by the hepatitis A virus (HAV).

Description

Hepatitis A is a form of viral hepatitis also known as infectious hepatitis, due to its ability to be spread through personal contact. Hepatitis A is a milder liver disease than hepatitis B , and asymptomatic infections are very common, especially in children. Hepatitis A does not cause a carrier state or chronic liver disease. Once the infection ends, there is no lasting phase of illness. However, it is not uncommon to have a second episode of symptoms about a month after the first; this is called a relapse.

Transmission

HAV is found in the stool (feces) of persons infected with hepatitis A. HAV is usually spread from person to person by putting something in the mouth that has been contaminated with the stool of a person infected with hepatitis A. This is called fecal-oral transmission. Thus, the virus spreads more easily in areas where there are poor sanitary conditions or where good personal hygiene is not observed. Most infections result from contact with a household member who has hepatitis A. Blood-borne infection has been documented but is rare in the United States. The common modes of transmission of hepatitis A are as follows:

consuming food made by someone who touched infected feces
drinking water that is contaminated by infected feces (a problem in communities with poor sewage treatment facilities)
touching an infected person's feces, which may occur with poor hand washing
having direct contact in large daycare centers, especially where there are children in diapers
being a resident of states in which hepatitis A is more common
sexual contact with an infected perslin

Demographics

Hepatitis A has a worldwide distribution and is endemic in most countries. However, the incidence of the disease is declining in developed countries. There is a very high incidence in developing countries and rural areas. For example, in rural areas of South Africa, the rate of infection is 100 percent.

According to the Centers for Disease Control, HAV infects up to 200,000 Americans each year with the highest rate of hepatitis A being among children five to 14 years of age. Almost 30 percent of reported cases of hepatitis A occur among children under 15 years of age, chiefly because they are frequently in close contact with other children in school and at daycare. Approximately 15 percent of reported cases of hepatitis A occur among children or employees in daycare centers. The states with the highest incidence of hepatitis A account for 50 percent of the reported cases. According to the American Academy of Pediatrics, 11 states have a rate of HAV infection that is at least twice the national average, or 20 cases per every 100,000 people. The states are: Arizona, Alaska, California, Idaho, Nevada, New Mexico, Oklahoma, Oregon, South Dakota, Utah, and Washington.

Causes and symptoms

Hepatitis A is caused by HAV, also called Entero-virus 72, which was identified in 1973. The virus has an incubation period of three to five weeks. It enters the body via the gut and replicates in the digestive tract and spreads to infect the liver, where it multiplies. HAV is excreted in the stools for two weeks preceding the onset of symptoms.

Persons with hepatitis A may not have signs or symptoms of the disease and older persons are more likely to have symptoms than children. If present, symptoms are non-specific and usually include fever , tiredness, loss of appetite, nausea , abdominal discomfort, dark urine, and jaundice (yellowing of the skin and eyes). Symptoms usually last less than two months, but some persons can be ill for as long as six months.

When to call the doctor

Parents should call the doctor immediately if any of the following occurs:

A child has changes in symptoms, is confused, is difficult to wake up, is lethargic (sluggish), or irritable.
A child is unable to drink fluids.
A child's skikn is yellow in color.
A child has signs of dehydration such as no urine in over eight hours or a dry mouth.
A child starts to look very sick.

Diagnosis

Hepatitis A symptoms often go unrecognized because they are not specific to hepatitis A, thus a blood test (IgM anti-HAV) is required to diagnose HAV infection. This test detects a specific antibody, called hepatitis A IgM, that develops when HAV is present in the body.

Treatment

No specific treatment is available for hepatitis A. However, the following guidelines are often recommended:

Fluids and diet. The best treatment is to make sure that the child drinks a lot of fluids and eats well.
Rest. The child should rest while he or she has fever or jaundice. When fever and jaundice are gone, activity may be gradually increased as with the healthcare provider's approval.
Medications. The body's immune system fights the HAV infection. Once the child recovers from hepatitis A, the virus leaves the body. Medications, prescription or nonprescription, should not be given without consulting the doctor.

Nutritional concerns

Parents should ensure that their infected child has a well-balanced diet. Children with advanced liver disease need to follow specific diets issued by the treating physician. However, most children are not in this category, and no special diet is currently recommended for them, except that they should avoid eating fatty foods because the body has difficulty digesting fat when the liver is not working well.

However, adequate protein intake is important to regenerate liver cells. Children without liver cirrhosis require about 2–3 grams of protein per kilogram of body weight. Children with cirrhosis need an individual nutrition plan from their pediatric specialist or nutritionist.

Prognosis

Viral hepatitis symptoms usually last three weeks to two months but may last up to six months. Children may return to daycare one week after symptoms first appear, with the doctor's permission. Most children with hepatitis get better naturally without liver problems later in life. However, some children do have subsequent liver problems. For this reason, it is important to keep in close touch with the treating physician and to keep all followup appointments. Chronic, or relapsing, infection does not occur with hepatitis A. In the United States, serious complications are infrequent, and deaths are very rare.

Prevention

According to the Centers for Disease Control and Prevention (CDC), routine vaccination of children is the most effective way to lower the incidence of hepatitis A nationwide. The CDC encourages implementation of routine hepatitis A vaccination programs for children in the 17 states which have the highest rates of hepatitis A. Hepatitis A vaccine has been licensed in the United States for use in persons two years of age and older. The vaccine is recommended (before exposure to hepatitis A virus) for persons who are more likely to get hepatitis A virus infection or are more likely to get seriously ill if they do get hepatitis A. The vaccines licensed in the United States as of 2004 were HAVRIX(r) (manufactured by Glaxo SmithKline) and VAQTA(r) (manufactured by Merck & Co., Inc).

Parents should teach their children always to wash their hands with soap and water after using the bathroom and before preparing and eating food. Travelers should avoid water and ice if unsure of their purity, or they can boil water for one minute before drinking it.

Short-term protection against hepatitis A is available from immune globulin, a preparation of antibodies that can be given before exposure for short-term protection against hepatitis A and for persons who have already been exposed to HAV. It can be given before and within two weeks after suspected contact with the virus.

Parental concerns

The best way to prevent exposure to HAV is good habits in washing hands. Children should wash their hands every time they go to the bathroom. Good handwashing should be enforced at home and at daycare facilities. It is also very important to keep a clean environment, such as clean toilets, bathrooms, and clothing. If a child is diagnosed with HAV, other family members should be treated to prevent spread of the disease. The healthcare provider can help parents to plan treatment for the entire family.

KEY TERMS

Antibody —A special protein made by the body's immune system as a defense against foreign material (bacteria, viruses, etc.) that enters the body. It is uniquely designed to attack and neutralize the specific antigen that triggered the immune response.

Antigen —A substance (usually a protein) identified as foreign by the body's immune system, triggering the release of antibodies as part of the body's immune response.

Asymptomatic —Persons who carry a disease and are usually capable of transmitting the disease but who do not exhibit symptoms of the disease are said to be asymptomatic.

Endemic —Natural to or characteristic of a particular place, population, or climate.

Hepatitis A —Commonly called infectious hepatitis, caused by the hepatitis A virus (HAV). Most often spread by food and water contamination.

Immune globulin —Preparation of antibodies that can be given before exposure for short-term protection against hepatitis A and for persons who have already been exposed to hepatitis A virus. Immune globulin must be given within two weeks after exposure to hepatitis A virus for maximum protection.

Jaundice —A condition in which the skin and whites of the eyes take on a yellowish color due to an increase of bilirubin (a compound produced by the liver) in the blood. Also called icterus.

Vaccine —A substance prepared from a weakened or killed microorganism which, when injected, helps the body to form antibodies that will prevent infection by the natural microorganism.

See also Hepatitis B; Vaccination.

Resources

BOOKS

Achord, James. Understanding Hepatitis. Jackson: University of Mississippi Press, 2002.

Berkman, Alan, and N. Bakalar. Hepatitis A to G: The Facts You Need to Know About All the Forms of This Dangerous Disease. Clayton, Australia: Warner Books, 2000.

PERIODICALS

Arya, G., and W. F. Balistreri. "Pediatric liver disease in the United States: Epidemiology and impact." Journal of Gastroenterology & Hepatology 17, no. 5 (May 2002):521–25.

Averhoff, F. et al. "Control of Hepatitis A Through Routine Vaccination of Children." Journal of the American Medical Association 286, no. 23 (December 2001): 2968–73.

Ferreira, Cristina T. et al. "Immunogenicity and Safety of Hepatitis A Vaccine in Children with Chronic Liver Disease." Journal of Pediatric Gastroenterology & Nutrition 37, no. 3 (September 2003): 258–61.

Jenson, Hal B. "The changing picture of hepatitis A in the United States." Current Opinion in Pediatrics 16, no. 1 (February 2004): 89–93.

Shulman, Stanford T. "The History of Pediatric Infectious Diseases." Pediatric Research 55, no. 1 (January 2004): 163–176.

Murdoch, David L., et al. "Combined Hepatitis A and B Vaccines: A Review of Their Immunogenicity and Tolerability." Drugs 40, no. 5–6 (May-June 2004): 265–69.

ORGANIZATIONS

American Liver Foundation (ALF). 75 Maiden Lane, Suite 603, New York, NY 10038–4810. Web site: <www.liverfoundation.org>.

National Center for Infectious Diseases (NCID). Centers for Disease Control and Prevention, Mailstop C-14, 1600 Clifton Road, Atlanta, GA 30333. Web site: <www.cdc.gov/ncidod>.

Hepatitis Foundation International (HFI). 504 Blick Drive, Silver Spring, MD 20904–2901. Web site: <www.liverfoundation.org>.

WEB SITES

"Viral Hepatitis A Homepage." NCID. Available online at <www.cdc.gov/ncidod/diseases/hepatitis/a/index.htm> (accessed October 22, 2004.)

"What I need to know about Hepatitis A Homepage." NIHNDDIC. Available online at <http://digestive.niddk.nih.gov/ddiseases/pubs/hepa_ez/> (accessed October 22, 2004).

Monique Laberge, Ph.D.

Gale Encyclopedia of Children's Health: Infancy through Adolescence Laberge, Monique

Hepatitis

views updated May 21 2018

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

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

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).

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