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Hepatitis B is an infection and inflammation of the liver caused by the hepatitis B virus. It is one of several types of hepatitis.
What is going on in the body?
The liver is an important organ located in the upper right quadrant of the abdomen. It is responsible for:
Infection of the liver by a virus can cause hepatitis, which is a term that means inflammation of the liver. Hepatitis can interfere with normal liver functions. Symptoms of hepatitis B, one of several viruses that can cause hepatitis, can quickly appear. This is called acute hepatitis. Symptoms of infection with the virus can also develop slowly and last a long time. This is called chronic hepatitis. Hepatitis B virus infections can range from mild to severe.
- filtering the blood
- making bile, a substance that aids in digestion and helps rid the body of harmful substances
- processing fats and sugars, helping the body store energy for later use
- making important proteins, such as those involved in blood clotting
- metabolising many medications, such as barbiturates, sedatives, and amphetamines
- storing vitamins A, B12, D, and several of the B-complex vitamins. The liver also stores iron and copper.
The hepatitis B virus is transmitted through the blood. After entering the bloodstream, the virus invades the liver cells. It reproduces there and can kill liver cells directly. Many of the symptoms of the disease, including liver inflammation, are caused by the body's immune system reacting to infection with the virus.
What are the signs and symptoms of the infection?
With acute hepatitis B, symptoms can vary. In fact, sometimes there are no symptoms. This is called subclinical hepatitis. Hepatitis B can also cause symptoms similar to other types of hepatitis, such as: These symptoms may last 1 to 3 months. Only half of the people with hepatitis B will develop jaundice, a yellowing of the skin and eyes. The liver can be mildly enlarged and tender. There are usually no other physical signs.
Symptoms of chronic hepatitis B infection also vary. There may not be any symptoms, or possibly only fatigue. There can be occasional worsening of symptoms that may resemble acute hepatitis. Persons with chronic hepatitis may develop cirrhosis, a long-term condition in which the normal tissue of the liver is replaced by scar tissue. Cirrhosis can lead to the following:
Rarely, acute fulminant hepatitis, which involves severe liver cell destruction and loss of liver function, occurs. It can be fatal. Symptoms include:
- spider angiomata, which are small, red dots on the skin containing tiny blood vessels
- palmar erythema, which is redness on the palms of the hands
- blood clotting problems
- ascites, an abnormal collection of fluid in the abdomen
- intestinal bleeding
- oedema, or swelling of the skin
- change in mental status or level of consciousness
- liver cancer
What are the causes and risks of the infection?
- an enlarged, painful liver
- enlarged spleen
- severe jaundice
- susceptibility to bleeding
- encephalopathy, a disorder in the functioning of the brain
- aplastic anaemia in rare cases. Aplastic anaemia is a condition in which the bone marrow cannot make enough red and white blood cells.
Hepatitis B is spread through exposure to infected blood and by sexual intercourse. People at risk include those who:
What can be done to prevent the infection?
- puncture themselves with contaminated needles and syringes, such as intravenous drug abusers or healthcare workers
- are stuck with contaminated needles during tattooing, acupuncture, or body piercing
- are sexually promiscuous, whether homosexual or heterosexual
- have had an organ transplant or blood transfusion, though blood is now screened for hepatitis B to prevent this form of transmission
People can prevent this infection by:
Hepatitis B immunoglobulin, is a special medication composed of antibodies to the hepatitis B virus. It is used to treat babies born to mothers with hepatitis B. It is also given to people exposed to hepatitis B, for instance, by an accidental needle stick. It confers immediate immunity. Hepatitis B immunoglobulin can be given at the same time as the hepatitis B vaccine.
- avoiding high risk behaviours such as intravenous drug use and needle punctures
- practicing safer sex
- having the hepatitis B vaccine
How is the infection diagnosed?
The doctor may suspect hepatitis B after doing a physical examination and checking liver function tests. Another blood test, often drawn at the same time as the liver function tests, can confirm that hepatitis B is the cause of the symptoms. A biopsy of the liver or other affected organs may be needed, depending on the type of hepatitis B.
What are the long-term effects of the infection?
Chronic hepatitis can lead to:
What are the risks to others?
- cirrhosis and liver failure in adults, which does not generally occur in children. Cirrhosis causes multiple problems, including the possibility of liver cancer.
- illnesses in other parts of the body, such as kidney damage or low blood counts
- cancer of the liver
- increased risk of death in people with HIV
The hepatitis B virus has been found in blood, saliva, semen, and vaginal secretions of infected individuals. It can be spread by sexual contact with an infected person, passed on to a newborn from an infected mother during childbirth, or transmitted through contact with infected blood or bodily fluids.
What are the treatments for the infection?
Treatment of hepatitis B includes: Treatment of chronic hepatitis B may involve the use of medications such as the antiviral medication alpha interferon. Other medications may include ribavirin, lamivudine, steroids, and antibiotics.
Treating people with complications in other parts of the body as a result of chronic hepatitis B can be complex. It can include corticosteroids, such as prednisone, chemotherapy-type medications, or plasmapheresis, which involves removing a component called plasma from the blood.
Acute fulminant hepatitis can cause life-threatening liver failure. This requires a hospital stay and treatment for the bleeding disorder, as well as for encephalopathy and nutritional problems. Sometimes the only effective treatment is a liver transplant.
What are the side effects of the treatments?
Side effects will depend on the treatments used. Side effects of interferon include a flu-like illness, with fever and body aches.
Liver transplant can cause many problems, including failure or rejection of the new liver. After a liver transplant, a person will need to take powerful anti-rejection medications for the rest of his or her life. Side effects of these medications increase the risk for infections, certain cancers, and other problems.
What happens after treatment for the infection?
The goal of treatment for chronic hepatitis B is to suppress or eliminate the virus. This does occur in some people, although relapses, or a return of symptoms, can occur. Some people can be started on the same treatment again if a relapse occurs.
After a liver transplant, people are kept on strong medications to prevent rejection of the liver.
How is the infection monitored?
Periodic visits to the doctor and liver function tests will be used to monitor the hepatitis and to see how the liver is working. The status of the liver may require repeated liver biopsies. Decisions for further treatment or liver transplantation are frequently made based on these tests. Any new or worsening symptoms should be reported to the doctor.
Author: Thomas Fisher, MD
Reviewer: HealthAnswers Australia Medical Review Panel
Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia
Last Updated: 1/10/2001
Potential conflict of interest information for reviewers available on request