Hepatitis b, chronic

[Oralee]

Chronic hepatitis B is inflammation of the liver that is caused by the hepatitis B virus and that has lasted more than 6 months.

Most people with chronic hepatitis B have no symptoms, but some feel generally ill and tired and lose their appetite.
Having chronic hepatitis B increases the risk of liver cancer.
Doctors diagnose hepatitis B based on blood tests and occasionally do a liver biopsy to determine how damaged the liver is.
Not all patients with chronic hepatitis B need treatment, but if chronic hepatitis B is damaging the liver (causing inflammation or scarring), an antiviral drug is started.
Treatment with antiviral drugs can help suppress the virus, prevent further inflammation and scarring in the liver, and allow any already damaged areas to heal.

(See also Overview of Hepatitis, Overview of Chronic Hepatitis, and Hepatitis B, Acute.)
An estimated 850,000 to 2.2 million people in the United States and about 257 million people worldwide have chronic hepatitis B.
In the Far East and parts of Africa, hepatitis B virus accounts for many cases of chronic hepatitis, cirrhosis (severe scarring of the liver), and liver cancer.
Overall, about 5% to 10% of people with acute hepatitis B develop chronic hepatitis B. The younger the person is when acute hepatitis B occurs, the higher the risk of developing chronic hepatitis B:

Infants: 90%
Children aged 1 to 5 years: 25 to 50%
Adults: About 5%

If the level of hepatitis B virus (viral load) is high in pregnant women, they are often given antiviral drugs during the last trimester of pregnancy to prevent transmission of the virus from mother to child.
Acute hepatitis B becomes chronic in about 40% of people being treated with hemodialysis and in up to 20% of people with a weakened immune system.
Chronic hepatitis B tends to worsen, sometimes rapidly but sometimes over decades, leading to cirrhosis. Chronic hepatitis B also increases the risk of liver cancer. About 20% of people with chronic hepatitis B develop cirrhosis or liver cancer and may die prematurely.
Some people who have chronic hepatitis B also have chronic hepatitis D. If untreated, the combination causes cirrhosis in up to 70% of affected people.

[Gregory]

Hepatitis B is a common cause of chronic hepatitis. Patients may be asymptomatic or have nonspecific manifestations such as fatigue and malaise. Without treatment, cirrhosis often develops; risk of hepatocellular carcinoma is increased. Antiviral drugs may help, but liver transplantation may become necessary.
(See also Causes of Hepatitis, Overview of Chronic Hepatitis, and Acute Hepatitis B.)
Hepatitis lasting gt; 6 months is generally defined as chronic hepatitis, although this duration is arbitrary.
Acute hepatitis B becomes chronic in about 5 to 10% of patients overall. However, the younger the age when acute infection occurs, the higher the risk of developing chronic infection:

For infants: 90%
For children aged 1 to 5 years: 25 to 50%
For adults: About 5%

The Centers for Disease Control and Prevention (CDC) estimates that 850,000 to 2.2 million people in the US (1) and about 257 million people worldwide have chronic hepatitis B (2).
Without treatment, chronic hepatitis B can resolve (uncommon), progress rapidly, or progress slowly to cirrhosis over decades. Resolution often begins with a transient increase in disease severity and results in seroconversion from hepatitis B e antigen (HBeAg) to antibody to hepatitis B e antigen (anti-HBe). Coinfection with hepatitis D virus (HDV) causes the most severe form of chronic HBV infection; without treatment, cirrhosis develops in up to 70% of patients. Chronic HBV infection increases the risk of hepatocellular carcinoma.