hepatic and biliary disorders
Hepatitis B, Chronic
Introduction
Hepatitis B is a common cause of chronic hepatitis. Patients may be asymptomatic or have nonspecific manifestations such as fatigue and malaise. Diagnosis is by serologic testing. Without treatment, cirrhosis often develops; risk of hepatocellular carcinoma is increased even without cirrhosis. Antiviral drugs do not cure but can control the virus. (See also Causes of Hepatitis , Hepatitis lasting>6 months is generally defined as chronic hepatitis, although this duration is arbitrary. Hepatitis B, Acute becomes chronic in about 5 to 10% of immunocompetent patients overall. However, the younger the age that acute hepatitis B occurs, the higher the risk of developing chronic hepatitis B: For infants: 90% For children aged 1 to 5 years: 25 to 50% For adults: About 5% Acute hepatitis B becomes chronic in about 40% of adults receiving hemodialysis and in up to 20% of people who are immunocompromised. The Centers for Disease Control and Prevention (CDC) estimates that 862,000 people in the US ( General references ), and the World Health Organization (WHO) estimates that about 257 million people worldwide, have chronic hepatitis B ( 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), followed by loss of hepatitis B surface antigen (HBsAg). Chronic HBV infection even in the absence of cirrhosis increases the risk of Hepatocellular Carcinoma . Coinfection with Hepatitis D (HDV) causes the most severe form of chronic HBV infection; without treatment, 