Hepatitis B

Introduction

The word "hepatitis" means inflammation of the liver. The usual cause of hepatitis is infection by a virus. At least six viruses, usually identified by the letters A through G, are known to cause hepatitis. In the United States, hepatitis A, hepatitis B, and hepatitis C are the most common.

Rarely, some kinds of hepatitis are not caused by infection. These non-contagious types of hepatitis can result from alcohol abuse, certain drugs, ingestion of toxic substances, or autoimmune disease (the body's own immune system attacks the liver).

Typically, hepatitis B has distinct phases. The first, or acute phase, occurs soon after infection with the hepatitis virus and lasts for six months or less. Many individuals recover from acute hepatitis, and their livers return to normal within a few months. Depending on the type of hepatitis, however, some of the individuals who contract acute hepatitis infections may not be able to eliminate the virus. For these individuals, the acute infection may be followed by a chronic phase. Usually, chronic hepatitis involves a prolonged "latent" or inactive period. During this time, which may last up to 20 years or longer, individuals with hepatitis probably do not experience symptoms or feel ill. Generally, however, the virus continues to multiply, gradually causing liver damage. Typically, symptoms do not become apparent until liver damage is extensive. However, abnormal levels of liver enzymes such as alanine aminotransferase (ALT) and aspartate aminotransferase (AST) may show if liver tests are done.

What is it?

Hepatitis B is a specific type of hepatitis caused by the virus that has been designated as hepatitis B virus (abbreviated as HBV), which causes inflammation and damage to the liver. As the virus infects more liver cells, inflammation and destruction of liver cells can interfere with the functions of the liver.

Most individuals are able to fight off (or clear) infection with HBV and they recover in two to four months. Ordinarily individuals only get hepatitis B once and after the HBV infection has been cleared, the individual has lifelong immunity. Up to 10% of adults, 50% of children under the age of five, and 90% of infants who contract hepatitis B will not be able to eliminate the virus in six months. These individuals are considered to be chronic carriers of HBV.

It is estimated that chronic hepatitis B affects 1.25 million people in the United States and leads to 5,000 U.S. deaths per year. There are an estimated 350 million people infected with hepatitis B globally. Approximately 70% of all new cases occur among people between the ages of 15 to 39 years. Chronic hepatitis puts individuals at a greater risk of developing cirrhosis or liver cancer. Cirrhosis is a condition that gradually replaces active liver cells with inactive scar tissue. Slowly, liver function is lost and liver failure may result. However, individuals who are chronic carriers of HBV but who have no symptoms are much less likely to develop cirrhosis than individuals who have chronic symptoms of hepatitis B.

What causes it?

The hepatitis B virus (HBV) is transmitted from individual to individual through contact with infected bodily fluids, such as blood. Because chronic carriers of HBV are often unaware that they have the virus, they may transmit the disease to others unknowingly. Injecting illegal drugs with contaminated needles or unprotected sexual contact with an infected individual are common ways to become infected. Sharing and reusing diabetes blood testing supplies with any infected individual may also cause an individual to become infected. In addition, instruments such as those used for tattooing and body piercing can spread hepatitis if they are not properly sterilized between uses. There is also a risk of becoming infected with HBV by using a shaving razor or toothbrush of an infected person. A mother who is infected can transmit HBV to her baby during childbirth. However, it is not transmitted through breast-feeding.

Once HBV makes its way to the liver, it multiplies. Symptoms usually develop within one to six months. Exactly how liver cells are damaged or why some people progress to chronic infection or liver cancer is unknown.

Who has it?

Hepatitis is the most common serious infectious disease. Up to 60,000 new cases of hepatitis B are reported each year in the United States, and the Centers for Disease Control and Prevention (CDC) estimates that 1.25 million Americans are infected with chronic hepatitis B.

Hepatitis B affects individuals of both sexes and all ages, ethnic groups, and sexual orientations. About one-fifth of the world's population will have hepatitis B at sometime in their lives. It is more common in males, with the highest occurrence between the ages of 20 and 49 years. Individuals with hemophilia may be slightly more at risk if they use clotting factors that are made from human blood.

In the United States, the acute form of hepatitis has been declining due to the availability of an effective vaccine and the aggressive promotion of vaccination among children and teenagers. Changes in high-risk behavior may also contribute to the decrease. In 1990, approximately 21,000 Americans were believed to have acute hepatitis B. By 2002, that number had dropped to approximately 8,000.

Chronic hepatitis B affects an estimated 1.25 million Americans and about 400 million chronic carriers are believed to exist in the world's population. As the number of acute cases goes down, the number of chronic carriers of hepatitis B is also expected to decline. However, increases in occurrence have been observed among the major risk groups: individuals with compromised immune systems, sexually active individuals, and injectable drug users.

What are the risk factors?

Risk factors are circumstances or conditions that can increase the chances of developing a condition. Some of these behaviors can be changed and taking special precautions may be helpful for limiting others. Risk factors for hepatitis B include:

• Receiving a tattoo or body piercing with contaminated instruments
• Living in or have lived in an area where the disease is common, especially among children
• Injectable drug use
• Poor socioeconomic conditions
• Unprotected sexual activity with homosexual or bisexual men
• Unprotected sexual activity with more than one partner in six months
• Travel to high-risk countries in Africa, Asia, South America, and Eastern and Mediterranean parts of Europe
• Exposure to bodily secretions of an infected individual
• Using a razor or toothbrush of an infected individual

Other individuals who may be at greater risk are:

• Dialysis patients
• Health care workers
• Individuals who received a blood transfusion prior to July 1992
• Individuals with hemophilia, especially those who used blood-derived clotting factors before 1987
• Infants born to infected mothers
• Sexual or household contacts of infected individuals

What are the symptoms?

Many individuals who contract HBV are not even aware that they have hepatitis because the symptoms may be so mild. The most common symptoms of hepatitis B are often mistaken for the flu and they may not be recognized because they may not appear until one to six months after becoming infected. Some of these symptoms may be:

• Fatigue (tiredness)
• Loss of appetite
• Mild fever
• Muscle or joint aches

Additional symptoms that may appear a few days after the initial symptoms include:

• Bitter taste in the mouth or bad breath
• Clay-colored (light) stools
• Confusion
• Dark urine
• Nausea and vomiting
• Pain on the right side below the ribs
• Widespread itching
• Yellow colored skin or white areas of eyes (jaundice)

The following symptoms of more serious liver damage may occur months to years later in individuals with chronic hepatitis B:

• Bruising easily or the appearance of spider veins-- broken blood vessels that form a tangled, spider-like appearance under the skin
• Changes in personality or behavior (an indicator of encephalopathy --a disease of the brain)
• Pain on the upper left side of stomach (due to an enlarged spleen)
• Red coloration of the palms of the hands
• Swelling of the legs and stomach (also called "ascites")
• Vomiting bright red blood or dark, grainy "coffee ground" material (as a result of bleeding from enlarged blood vessels in the esophagus and stomach)

How is it treated?

Hepatitis B that lasts beyond six months or becomes serious may be treated with several different medications, but not every case needs to be treated. Whether or not an individual with hepatitis B is taking medication, regular visits to a doctor who specializes in liver diseases are very important. Laboratory tests that measure liver function need to be performed regularly to track disease progression and to determine possible complications. Because no cure has been found for hepatitis B, treatment is aimed at decreasing the ability of the virus to multiply, decreasing inflammation and damage to the liver, and increasing the immune system's ability to fight the virus.

Currently, drug treatments seem to be most helpful for individuals who have liver disease caused by hepatitis B. Unfortunately, there is no drug treatment for the acute phase of hepatitis B. Nausea and vomiting often seen with early infection is treated with fluid replacement. In the United States, the five drugs that have been approved by the Food and Drug Administration (FDA) for treating chronic hepatitis B are:

Interferon-alpha (Intron A and Pegasys) --- A synthetic version of antiviral proteins produced by the immune system. Artificial interferon is used to treat a number of conditions. Interferon is approved for both children and adults with hepatitis B. It is given by injection several times a week. There is also a modified form of interferon known as peginterferon that has been approved for the treatment of Hepatitis B. It has a similar but larger chemical structure than interferon-alpha, which improves how the drug works and only needs to be injected once weekly. Interferon may cause side effects such as depression, headache and flu-like symptoms.

Lamivudine (Epivir-HBV)--- Taken orally once a day for at least a year, lamivudine is approved for use by both children and adults with chronic hepatitis B. It has very few side effects, but long term use of lamivudine is likely to cause the hepatitis virus to become resistant to the effects of this medicine. Because of this, combination therapy and the use of other medicines to treat hepatitis B are areas of intense study.

Adefovir dipivoxil (Hepsera)--- Approved only for adults with chronic hepatitis B, adefovir is taken once a day as an oral tablet. Studies have shown that use of adefovir has been beneficial in reducing the amount of virus in the body without causing as much resistance as lamivudine. The most common side effects experienced by patients taking this medicine are headache, sore throat, and stomach pain.

Entecavir (Baraclude)--- Approved by the FDA March 2005, entecavir resembles a product needed by the hepatitis B virus to continue growing. It has been approved for chronic hepatitis B patients in whom the virus is active and replicating. Entecavir can also be used in patients with a resistant virus who have failed lamivudine therapy. Entecavir, taken as an oral tablet or solution once daily, is tolerated as well as lamivudine. The hepatitis B virus is much less likely to develop resistance to entecavir, representing a convenient treatment option for chronically infected patients.

Telbivudine (Tyzeka)--- Approved by the FDA in October 2006, telbivudine works by inhibiting HBV DNA polymerase. HBV DNA polymerase normally works to help create more HBV virus molecules. Thus, telbivudine stops the replication of HBV. Telbivudine is taken once a day as an oral tablet. Studies have shown that telbivudine is slightly more effective than lamivudine while also having less side effects and being more tolerable.

Therapy with one drug is still considered to be the first-line treatment approach and the choice of drug is specific to each patient with chronic hepatitis B. Combination therapy with interferon alpha and a nucleoside analog (like lamivudine or entecavir) may be used to prevent viral resistance and has shown promising results in reducing viral replication. However, further studies are needed to fully evaluate the benefit of combination therapy over treatment with one drug. Your doctor may run tests to check the health of your liver if you are on medicines like adefovir, lamivudine, or entecavir. If you are on any of these medicines, tell your doctor if you experience abdominal pain, skin discoloration, orange or dark urine, and frequent diarrhea or constipation.

Prevention of hepatitis B

Hepatitis B cannot be cured, but it can be prevented relatively easily.

Before exposure to HBV

The hepatitis B vaccine (Engerix-B, Recombivax HB) is a safe and effective protection from hepatitis B. Given as three injections during a 6-month period, it generally produces immunity for 15 years or longer. Generally, the injections are given in a doctor's office or clinic. Another vaccine is called Twinrix, which is a vaccine that helps protect against both hepatitis A and hepatitis B. It is indicated for adults over the age of 18 and is an injection that is given in three doses. The first dose is given at the first visit, the second dose is given at the second month, and the last dose is given at the seventh month interval.

Currently, hepatitis B vaccination is required by many school districts before a student is admitted. It is recommended for all individuals under the age of 19 years and for individuals who:

• are homosexual men
• are undergoing kidney dialysis
• have liver diseases (including other types of hepatitis)
• have sex with a partner who has hepatitis B*
• have sex with multiple partners
• have or have ever had a sexually transmitted disease (for example, gonorrhea or syphilis)
• live in or travel to countries where hepatitis B is common
• live in the same home as an individual who has chronic hepatitis B
• may be exposed to HVB in blood

* Even if you have been vaccinated you should still use safe sex practices. The hepatitis B vaccine does not protect against any other sexually transmitted disease such as HIV. It is always important to practice safe sex.

After exposure to the virus

Individuals who know or believe that they have been exposed to HBV, including babies born to mothers who test positive for HBV, should receive the three hepatitis B vaccine injections. They should also get one injection of hepatitis B immune globulin (BayHep B, Nabi-HB). Abbreviated as HBIG, this medication is made up of immune system proteins that specifically help to fight HBV.

Helping Yourself

For individuals who already have hepatitis B, the following tips can be helpful:

• See the doctor regularly so that progress can be closely monitored. Follow the doctor's advice for taking medications to treat symptoms.
• Get plenty of bed rest until fever disappears and jaundice (yellow coloration of skin and eyes) fades away. Be sure to check with the health care provider about how much bed rest will be needed.
• Avoid becoming too active during the first few months as symptoms start to improve.
• Eat small, balanced meals. Try to include green and yellow vegetables, such as cabbage, broccoli, and carrots, which contain nutrients that benefit the liver. If nausea becomes a problem, taking hard candy, juice, or lightly carbonated beverages may help. Dividing large meals into several smaller snacks that are eaten throughout the day helps control nausea for some individuals.
• Check with a doctor or health care provider before taking any medication, including over-the-counter products, vitamins, or herbal supplements.
• Do not drink alcohol.

To prevent the spread of hepatitis B to others, an infected individual should take the following precautions:

• Avoid sexual intercourse until a doctor confirms that the infectious period has passed. Use latex condom correctly for every sex encounter (even if the infectious period is thought to be over).
• Do not share anything that may have blood on it, including toothbrushes, razors, needles, or syringes.
• Make sure all of the individuals, especially sexual partners of the individual infected with HBV, in the household get the hepatitis B vaccine.
• Use a disinfectant to clean up any bloodstains.

Although it is necessary to take precautions, it is also important to know that HBV CANNOT be spread to others by the following actions:

• Breast-feeding
• Casual contact (such as the workplace)
• Coughing
• Eating food or drinking water
• Hugging
• Kissing
• Sharing a glass or eating utensil
• Sneezing

What is on the horizon?

Many antiviral and immune system-stimulating drugs are being investigated.

• Combinations of interferon, antivirals, and other immune-stimulating drugs show promise but have not yet been approved. Some of the possible combinations include interferon with famciclovir (an antiviral medication that is currently approved for treatment of other viral infections such as herpes).
• Emtricitabine (Coviracil) and Tenofovir DF (Viread), antiviral drugs approved for the treatment of AIDS, are being tested alone and in combination with other drugs for the treatment of chronic hepatitis B.
• Clevudine is an additional antiviral drug that is being evaluated for the treatment of chronic hepatitis B.
• Lobucavir, a new antiviral that blocks reproduction of the hepatitis B virus, is in final stages of clinical study. If approved, it will be taken orally once a day.
• Alkovirs are a new class of drugs in early human trials. While the focus of research for alkovirs is hepatitis C, these agents also appear to be effective against HBV. Studies have shown that alkovirs may activate the body's own defense system to fight the viruses that cause both hepatitis B and hepatitis C.
• Another new class of drugs called "methoxys" is a highly modified version of older drugs called glucovirs that are similar in chemical structure to alkovirs. Glucovirs were not developed because they had too many side effects, but methoxys have been shown to be more effective and much less toxic than glucovirs.

In other research, blood and urine tests for early detection of the liver complications that may be associated with hepatitis B, are very close to being approved. Researchers have already been able to isolate proteins and markers of liver cancer and liver disease in individuals affected by hepatitis B.

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Hepatitis B Health Condition Last Updated: June 2008

Note: The above information is intended to supplement, not substitute for, the expertise and judgment of your physician, pharmacist, or other healthcare professional. It is not intended to diagnose a health condition, but it can be used as a guide to help you decide if you should seek professional treatment or to help you learn more about your condition once it has been diagnosed.

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