Hepatitis B

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.

Symptoms

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.