Hepatitis B

Signs and symptoms      Causes      Transmission       Risk factors      Diagnosis        Treatment

Hepatitis B is a serious liver infection caused by the hepatitis B virus (HBV). For some people, the infection becomes chronic, leading to liver failure, liver cancer, or cirrhosis ? a condition that causes permanent scarring of the liver.

The hepatitis B virus is transmitted through contact with the blood and body fluids of someone who is infected. You’re especially at risk if you are an intravenous (IV) drug user who shares needles or other paraphernalia, have unprotected sexual contact with an infected partner, or were born in or travel to parts of the world where hepatitis B is widespread. In addition, women with HBV can pass the infection to their babies during childbirth.

Most people infected as adults recover fully from hepatitis B, even if their signs and symptoms are severe. Infants and children are much more likely to develop a chronic infection. Although no cure exists for hepatitis B, a vaccine can prevent the disease. If you’re already infected, taking certain precautions can help prevent spreading HBV to others.


Signs and symptoms

Most infants and children with hepatitis B never develop signs and symptoms. The same is true for some adults. Signs and symptoms usually appear 12 weeks after you’re infected and can range from mild to severe. They may include some or all of the following:

* Loss of appetite
* Nausea and vomiting
* Weakness and fatigue
* Abdominal pain, especially around your liver
* Dark urine
* Yellowing of your skin and the whites of your eyes (jaundice)
* Joint pain

Hepatitis B can damage your liver ? and spread to other people ? even if you don’t have any signs and symptoms. That’s why it’s important to be tested if you think you’ve been exposed to hepatitis B or if you engage in behavior that puts you at risk.

Causes
Your liver is primarily located on the right side of your abdomen, just beneath your lower ribs. It performs many functions, including processing most of the nutrients absorbed from your intestines, removing drugs, alcohol and other harmful substances from your bloodstream, and manufacturing bile ? the greenish fluid stored in your gallbladder that helps digest fats. Your liver also produces cholesterol, blood-clotting factors and certain other proteins.

The liver has an amazing capacity for regeneration ? it can heal itself by replacing or repairing injured tissue. In addition, healthy cells take over the function of damaged cells, either indefinitely or until the damage has been repaired. Yet in spite of this, your liver is prone to a number of diseases that can cause serious or irreversible damage, including hepatitis B.

Acute vs. chronic hepatitis B
Hepatitis B infection may be either acute ? lasting less than six months ? or chronic, lasting six months or longer. If the disease is acute, your immune system is usually able to clear the virus from your body, and you should recover completely within a few months. When your immune system can’t fight off the virus, HBV infection may become lifelong, possibly leading to serious illnesses such as cirrhosis and liver cancer.

Most people who acquire hepatitis B as adults have an acute infection. But the outlook isn’t nearly as hopeful for infants and children. Most infants infected with HBV at birth and many children infected between 1 and 5 years of age become chronically infected. Chronic infection may go undetected for decades until a person becomes seriously ill from liver disease.

Hepatitis B is one of six currently identified strains of viral hepatitis ? the others are A, C, D, E and G. Each strain is unique, differing from the others in severity and in the way it spreads.

Major ways transmission occurs
In industrialized countries, you’re most likely to become infected with HBV in the following ways:

* Sexual transmission. You may become infected if you have unprotected vaginal, anal or oral sex with an infected partner whose blood, saliva, semen or vaginal secretions enter your body. You can also become infected from shared sexual devices if they’re not washed or covered with a condom. The virus is present in the secretions of someone who’s infected and enters your body through small tears that can develop in your rectum or vagina during sexual activity.
* Transmission through needle sharing. HBV is easily transmitted through needles and syringes contaminated with infected blood. That’s why sharing IV drug paraphernalia puts you at high risk of hepatitis B. Your risk increases if you inject drugs frequently or also engage in high-risk sexual behavior. Although avoiding the use of injected drugs is the most reliable way to prevent infection, you may not choose to do this. If so, one way to reduce your risk is to participate in a needle exchange program in your community. These programs allow you to exchange used needles and syringes for sterile equipment. In addition, consider seeking counseling or treatment for your drug use.
* Transmission through accidental needle sticks. Hepatitis B is a concern for health care workers and anyone else who comes in contact with human blood. If you fall into one of these categories, get vaccinated against hepatitis B in addition to following routine precautions when handling needles and other sharp instruments.
* Transmission from mother to child. Pregnant women infected with HBV can pass the virus to their babies. If you have hepatitis B, having your baby receive a shot of hepatitis B immune globulin at birth, along with the first in a series of three hepatitis B vaccines, will greatly reduce your baby’s risk of getting the virus.

Ways transmission does NOT occur
For you to become infected with HBV, infected blood, semen, vaginal secretions or saliva must enter your body. You can’t become infected with hepatitis B in any of the following ways:

* Casual contact, such as hugging, dancing or shaking hands
* Coming into contact with the sweat or tears of someone with HBV
* Sharing a swimming pool, telephone or toilet seat with someone who has the virus
* Donating blood

Risk factors

Anyone of any age, race, nationality, sex or sexual orientation can be infected with HBV. But you’re at greatest risk if you:

* Have unprotected sex with more than one partner. You’re at risk whether you’re heterosexual, homosexual or bisexual. Unprotected sex means having sex without using a new latex or polyurethane condom every time.
* Have unprotected sex with someone who’s infected with HBV.
* Have a sexually transmitted disease such as gonorrhea or chlamydia.
* Share needles during intravenous (IV) drug use.
* Share a household with someone who has a chronic HBV infection.
* Have a job that exposes you to human blood.
* Received a blood transfusion or blood products before 1972.
* Receive hemodialysis for end-stage kidney (renal) disease.
* Travel to regions with high infection rates of HBV, such as sub-Saharan Africa, Southeast Asia, the Amazon Basin, the Pacific Islands and the Middle East.
* Are an adolescent or young adult residing in a U.S. correctional facility.

Newborns whose mothers are infected with HBV also are at high risk. The same is true of infants and children whose parents were born in areas where HBV infection is widespread. In many developing countries, the most common method of transmission of the virus is between mother and child or among children living in the same household.

Sometimes you may become infected with HBV even if you have no known risk factors for the disease.

Seek medical care if you have signs or symptoms of hepatitis B or are at risk of the disease and haven’t been vaccinated or don’t know if you’re protected.

Most children in the United States now receive HBV vaccine along with other routine shots. But some children ? especially those who don’t have access to regular medical care or whose parents are from countries with high infection rates ? may be overlooked. If your child hasn’t been vaccinated, contact a doctor, your state health department or a public health clinic. Many states offer low-cost or free vaccines for those who need them.

Lifelong monitoring of liver function and screening for liver cancer are important for adults and children with chronic HBV infection. If you or your child has already developed signs of liver disease, your doctor can refer you to a specialist for additional care.

Screening and diagnosis

If you’re pregnant, it’s important to be checked for HBV early in your pregnancy. Also, get tested if you have unprotected sex with more than one partner, share needles when injecting drugs or have spent time in an area where hepatitis B is widespread.

People who adopt children from areas where hepatitis B is common should consider having their children tested when they arrive in the United States. To best meet the special needs of adopted children, doctors usually make testing for HBV part of a comprehensive health evaluation.
You and your children can be tested at your doctor’s office, a hospital or a public health clinic. Many public clinics offer free testing for HBV and other sexually transmitted diseases. Testing is important to protect you and your children and to prevent transmission of the virus to others.
Diagnosis based on tests
Because many people with hepatitis B don’t have signs and symptoms, doctors diagnose the disease on the basis of one or more blood tests. These tests include:

* Hepatitis B surface antigen (HBsAg). Hepatitis B surface antigen is the outer surface of the virus. Testing positive for this antigen means you can easily pass the virus to others. A negative test means you’re probably not currently infected.
* Antibody to hepatitis B surface antigen (anti-HBs). A positive result on this test means you have antibodies to HBV. This may be due to a prior HBV infection from which you’ve recovered. Or, you may already have been vaccinated. In either case, you can’t infect others or become infected yourself because you’re protected by the vaccine or your own natural immunity.
* Antibody to hepatitis B core antigen (anti-HBc). Although this test identifies people who have a chronic infection, the results can sometimes be ambiguous. If you test positive for hepatitis B core antibodies, you may have a chronic infection that you can transmit to others. But you also may be recovering from an acute infection or have a slight immunity to HBV that can’t otherwise be detected. How this test is interpreted often depends on the results of the other two tests. When the results are uncertain, you may need to repeat all three tests.

Additional tests
If you receive a diagnosis of hepatitis B, your doctor may perform tests to check the severity of the HBV infection as well as the health of your liver. These tests include:

* E-antigen test. This blood test looks for the presence of a protein secreted by HBV-infected cells. A positive result means you have high levels of the virus in your blood and can easily infect others. If the test is negative, you have lower blood levels of HBV and are less likely to spread the infection.
* Liver enzymes. These blood tests check for elevated levels of liver enzymes which leak into the bloodstream when liver cells are injured.
* Alpha-fetoprotein (AFP) test. High blood levels of this protein may sometimes be a sign of liver cancer.
* Hepatitis B DNA test. This test detects HBV DNA in the blood, indicating how much virus is present in your blood.
* Liver ultrasound or computerized tomography (CT) scan. These tests look at the liver for complications such as liver scarring (cirrhosis) or liver cancer.
* Liver biopsy. In this procedure, a small sample of liver tissue is removed for microscopic analysis. A biopsy can accurately show the extent of any liver damage and may help determine the best treatment for you.

Having a chronic HBV infection eventually may lead to serious liver diseases such as cirrhosis and liver cancer. Having had HBV infection as an infant or child gives you a greater chance of developing these illnesses as an adult.
In addition, hepatitis B puts you at risk of acute liver failure ? a condition in which all the vital functions of the liver shut down. When that occurs, a liver transplant is necessary to sustain life.
Anyone chronically infected with HBV is also susceptible to infection with another strain of viral hepatitis ? hepatitis D. Formerly known as delta virus, the hepatitis D virus needs the outside coat of HBV in order to infect cells. You can’t become infected with hepatitis D unless you’re already infected with HBV.

Injection drug users with hepatitis B are most at risk, but you can also contract hepatitis D if you have unprotected sexual contact with an infected partner or live with someone infected with hepatitis D. Having both hepatitis B and hepatitis D makes it more likely you’ll develop cirrhosis or liver cancer.

Treatment

If you know you’ve been exposed to hepatitis B virus, call your doctor immediately. Receiving an injection of hepatitis B immune globulin within 24 hours of coming in contact with the virus may help protect you from developing hepatitis B. You should also receive the first in a series of three shots of the hepatitis B vaccine.

Once you’ve developed chronic hepatitis B, few treatment options exist. In some cases ? especially if you don’t have signs and symptoms or liver damage ? your doctor may suggest monitoring, rather than treating, your condition. In other cases, your doctor may recommend treatment with antiviral medications. When liver damage is severe, liver transplantation may be the only option.

Drug therapies
Doctors use five drugs to treat chronic HBV infection

* Interferon. Your body naturally produces interferon to help protect against invading organisms such as viruses. Taking additional interferon that has been made in a laboratory may stimulate your body’s immune response to HBV and help prevent the virus from replicating in your cells. Not everyone is a candidate for treatment with interferon. In a few cases, interferon eliminates the virus completely, although the infection can later return. Interferon has a number of side effects ? many of which resemble signs and symptoms of hepatitis B. These include depression, fatigue, muscle pains, body aches, fever and nausea. Signs and symptoms are usually worse during the first two weeks of treatment and in the first four to six hours after receiving an injection of interferon. A more serious side effect that may occur over time is a decreased production of red blood cells. Two interferon medications are available ? interferon alfa-2b (Intron A) and peginterferon alfa-2a (Pegasys). Intron A is given by injection several times a week. Pegasys is given by injection once a week.
* Telbivudine (Tyzeka). This antiviral medication helps prevent HBV from replicating in your cells. It’s taken in pill form once a day and has almost no side effects for up to a year. Studies show telbivudine is more effective than are other common treatments such as lamivudine and adefovir dipivoxil. However, you can experience a severe worsening of symptoms when you stop taking the drug. And telbivudine can cause a drug-resistant form of HBV, particularly when taken as a long-term treatment.
* Entecavir (Baraclude). This antiviral medication is taken once a day in pill form. Studies comparing Baraclude with lamivudine found Baraclude to be more effective. Baraclude may cause serious worsening of symptoms when the drug is stopped.
* Lamivudine (Epivir-HBV). This older antiviral medication is similar to telbivudine, though slightly less strong. It’s usually taken in pill form once a day. Side effects during treatment are generally minimal, but you may experience a severe worsening of symptoms when you stop taking the drug. Lamivudine can also cause a drug-resistant form of HBV, particularly when taken as a long-term treatment. Tell your doctor if you have kidney problems or a history of pancreatitis before starting this medication. If you experience worsening jaundice or any unusual bruising, bleeding or fatigue while taking lamivudine, call your doctor right away.
* Adefovir dipivoxil (Hepsera). This drug, taken in pill form once daily, also helps prevent HBV from replicating in your cells. An added benefit is that it’s effective in people who are resistant to lamivudine. Like lamivudine, side effects during treatment usually are minimal, but symptoms may worsen when you go off the medication. And Hepsera may cause kidney problems.

Liver transplantation
When your liver has been severely damaged, a liver transplant may be an option. The encouraging news is that these transplants are increasingly successful. Unfortunately, not enough donor organs are available for every person who needs a transplant.

A number of hepatitis B vaccines are available. They have typically been given in a series of three immunizations at zero, one and six months, but some can also be given in an accelerated four-dose schedule. Another is given in two doses in adolescents ages 11 to 15. These vaccines provide more than 90 percent protection for both adults and children, and they generally protect against HBV for at least 23 years. You can’t get hepatitis B from the vaccine.
Almost anyone can receive the vaccine, including infants, older adults and those with compromised immune systems. Infants often receive the vaccine in the first year of life ? typically at 2, 4 and 9 months of age.
Side effects tend to be mild and may include weakness, fatigue, headache, nausea, and soreness or swelling at the injection site. Although concerns have been raised that the HBV vaccine may increase the risk of autoimmune disease, studies have found no connection.
Although vaccination is the best way to protect yourself and others from hepatitis B, the measures listed below also can help guard against HBV infection or help manage HBV if you have it.

If you’re not infected with HBV
The following measures can help keep you from becoming infected with HBV:

* Educate yourself and others. Make sure you understand what HBV is and how the virus is transmitted.
* Know the HBV status of any sexual partner. Don’t engage in unprotected sex unless you’re absolutely certain your partner isn’t infected with HBV, HIV or any other sexually transmitted disease.
* Use a new latex or polyurethane condom every time you have sex. If you don’t know the health status of your partner, use a new latex condom every time you have anal or vaginal sex. If you’re allergic to latex, use a plastic (polyurethane) condom. Avoid lambskin condoms because they don’t protect you from sexually transmitted viruses. If you don’t have a male condom, use a female condom. Use only water-based lubricants, not petroleum jelly, cold cream or oils. Oil-based lubricants can weaken condoms and cause them to break. During oral sex use a condom, dental dam (a piece of medical-grade latex) or plastic wrap. Remember that although condoms can reduce your risk of contracting HBV, they don’t eliminate the risk entirely. Condoms can break or develop small tears, and people don’t always use them properly.
* Use a sterile needle. If you use a needle to inject illicit drugs, make sure it’s sterile, and don’t share it. Take advantage of needle exchange programs in your community and consider seeking help for your drug use.
* Talk to your doctor if you’re traveling internationally. If you’re planning an extended trip to a region where hepatitis B is endemic, ask your doctor about the hepatitis B vaccine well in advance. It’s usually given in a series of three injections over a six-month period.
* Be cautious about blood products in certain countries. Although the blood supply is now well screened in the United States, this isn’t always the case in other countries. If an emergency requires that you receive blood or blood products in another country, get tested for HBV as soon as you return home.
* If you’re pregnant, get tested. Knowing whether you’re infected with HBV can allow you and your doctor to take steps to protect your child.

If you’ve received a diagnosis of HBV, the following guidelines can help protect others:

* Practice safe sex. The only foolproof way to protect your sexual partner or partners from HBV infection is to avoid practices that expose them to blood, saliva, semen and vaginal secretions. Barring that, carefully follow guidelines for safe sex, including using a new latex condom every time you have vaginal or anal sex and using a dental dam, condom or piece of plastic wrap during oral sex. If you use sexual devices, don’t share them.
* Tell your sexual partner(s) you have HBV. Let anyone with whom you’ve had sex know that you have HBV. Your partners need to be tested and receive medical care if they have the virus. They also need to know their HBV status so that they don’t infect others.
* Don’t share needles or syringes. If you use IV drugs, never share your needles and syringes with anyone.
* Don’t donate blood or organs. Donating infected blood or organs spreads the virus.
* Don’t share razor blades or toothbrushes. These items may carry traces of infected blood. Some experts also suggest not sharing your comb, hairbrush and nail clippers.
* If you’re pregnant, tell your doctor you have HBV. That way, your baby can be treated as soon as he or she is born.

If you’ve received a diagnosis of hepatitis B, your doctor will likely recommend certain lifestyle changes. These simple measures will help keep you healthy longer:

* Avoid drinking alcohol. Alcohol speeds the progression of liver disease.
* Avoid medications that may cause liver damage. Your doctor can advise you about these medications, which may include over-the-counter (OTC) medications as well as prescription drugs. It’s especially important to avoid using acetaminophen (Tylenol, others), which can cause liver damage even in healthy people.
* Eat the healthiest diet you can. Eat fresh fruits and vegetables, whole grains and lean protein. Healthy foods help keep you strong, give you more energy and support your immune system. If you’re nauseated, try eating small meals throughout the day. Choose foods that are soothing and easy to digest, such as soups, broths or a plain baked potato. A registered dietitian can be especially helpful if you have weight loss or trouble eating.
* Get regular exercise. Exercise helps increase your strength and energy levels.
* Get enough sleep. Rest when you need to.