What Is It?
Hepatitis B remains the most common form of chronic viral hepatitis (liver inflammation) throughout the world, although immunization programs have reduced the number of cases in the United States. During World War II, doctors recognized that some patients developed hepatitis after receiving injections or blood transfusions. They realized that the infection spreads through contact with infected blood, and called the infection hepatitis B. However, with improved testing methods, it is now extremely rare to contract hepatitis B through a blood transfusion.
In the U.S., hepatitis B typically is spread during sexual activity and through needle sharing among intravenous drug users. The virus also can be transmitted by sharing razors or when being pierced or tattooed in facilities with poor sanitary conditions.
In developing countries, the virus commonly is passed from mother to infant at the time of delivery. It also is spread through contaminated blood transfusions. Worldwide, health care workers continue to be at risk of hepatitis because of their exposure to infected patients, although immunization with the hepatitis B vaccine has decreased the rate of infection in this group.
The hepatitis B virus can cause short term (acute) hepatitis, which may or may not cause symptoms. Most people will clear the virus from their systems, but a minority will develop a persistent infection called chronic hepatitis, which can range from mild to severe. Patients with chronic hepatitis remain infectious, and can pass on the virus to others. Some people are not able to rid their body of the infection, but they do not have any symptoms of disease. They are called “carriers,” and can pass the infection to others.
The symptoms of short term hepatitis B vary, and can include loss of appetite, nausea, vomiting, fatigue, headache and fever. These symptoms may be followed by jaundice, an abnormal accumulation of the chemical bilirubin in the blood, which causes yellowing of the eyes, skin and body fluids (such as tears), as well as a darkening of the urine. Other symptoms of hepatitis can include itching, weight loss, abdominal pain, sleep disturbance, confusion and loss of sex drive.
Most people recover from short term hepatitis and are no longer infected with the virus when their illness ends. However, up to 10 percent of adults may develop long term (chronic) hepatitis. If an infant is infected with hepatitis B at the time of birth, this is usually a silent infection that carries with it a greater than 90 percent risk of becoming a chronic infection.
People with long term hepatitis can have a broad range of symptoms. Some may not have any symptoms, while others suffer from debilitating disease. The most common symptoms include fatigue, yellow skin (jaundice), an ill feeling (malaise), decreased appetite and aching joints. A small number of people with chronic hepatitis develop liver cirrhosis. These people may develop symptoms of advanced liver disease, including jaundice, fluid within the abdominal cavity (ascites), swelling of the legs and changes in mental status such as difficulty concentrating or confusion. People with hepatitis B who develop cirrhosis are at risk of developing liver cancer.
Your doctor will ask about any potential exposures to hepatitis, including your past and present history of illegal drug use and unprotected sexual activity. Your doctor will conduct a physical examination, looking at your skin and eyes, and at your abdomen for evidence of fluid accumulation and to estimate the size of your liver.
Your doctor will order blood tests to check the function of your liver, including measurements of bilirubin, which is associated with jaundice, and liver aminotransferase enzymes. High enzyme levels generally indicate the presence of liver inflammation. Blood tests for levels of cholesterol, albumin or prothrombin may be necessary to assess the severity of liver damage.
The diagnosis can be confirmed with blood tests to detect the presence of virus particles themselves or antibodies, which are proteins produced by your immune system to attack the hepatitis B virus. People who have completely recovered from an acute hepatitis B infection usually will have detectable levels of antibodies in their blood, but no detectable viral particles. People with an active infection — either an acute infection or chronic disease — usually will have detectable levels of viral particles in their blood.
If your doctor suspects that you have severe liver damage, he or she will recommend a liver biopsy to assess the amount of liver damage. In a biopsy, a small amount of tissue is removed and examined in a laboratory.
Most people who recover from an acute infection do so within two to 12 weeks. Although people may feel well during this time, blood tests can take up to three to four months to produce normal results.
Chronic hepatitis B can be treated with a variety of medications, although it rarely is cured.
You can prevent hepatitis B infection by avoiding situations that can lead to exposure to the virus, such as sharing needles for injecting intravenous drugs and having unprotected sex. In the U.S., a safe and effective hepatitis B vaccine is offered routinely to all children. This vaccine, given as a series of three injections, offers more than 90 percent protection against hepatitis B. Adults at high risk of exposure, including medical personnel, also should be immunized.
There is no treatment for acute hepatitis B, other than supportive care, which aims to alleviate symptoms. In rare cases, an episode of acute hepatitis can be unusually severe and may require hospital treatment. A small number of people will develop liver failure, and may need a liver transplant. Liver failure can lead to death.
Not all people with chronic hepatitis B require treatment. Antiviral medications such as interferon (Intron-A), lamivudine (Epivir), and adefovir dipivoxil (Hepsera) may be used for a person whose blood contains viral particles (antigens), if his or her liver is not functioning properly, and who has had a biopsy that shows evidence of liver damage. People with signs of progressive chronic liver disease can be considered for a liver transplant. Although this procedure can be life saving, the new liver usually becomes infected with hepatitis B eventually.
When To Call A Professional
Call your doctor if you develop symptoms of hepatitis. If you develop severe symptoms, you may require hospital treatment. If you know you have a chronic hepatitis B infection and you develop symptoms of advanced liver disease, such as swelling in your abdomen and legs, confusion or jaundice (yellow skin), seek immediate medical attention.
Severe acute hepatitis B can occur in about 1 percent of cases, and often is linked to the simultaneous transmission of another hepatitis virus, called hepatitis delta virus. Death rates in these rare cases of severe disease can exceed 80 percent. In most other cases of less severe hepatitis B, people recover completely after the short term infection, except for the small percentage of patients who go on to develop chronic hepatitis.
In people with chronic hepatitis B, the prognosis depends upon the severity of chronic liver inflammation, which can be determined through a liver biopsy. People with mild liver damage have a good prognosis, though some eventually develop cirrhosis or cancer. People with chronic active hepatitis and cirrhosis have a poorer prognosis, with a 55 percent chance of dying within five years.
Diseases and Conditions Center