Key Points
ÎAn estimated 350 million persons worldwide are chronically infected with the hepatitis B virus (HBV).
ÎIn the United States, there are an estimated 1.25 million hepatitis B carriers, defined as persons positive for hepatitis B surface antigen (HBsAg) for more than 6 months.
ÎCarriers of HBV are at increased risk of developing cirrhosis, hepatic decompensation, and hepatocellular carcinoma (HCC).
ÎAlthough most carriers will not develop hepatic complications from chronic hepatitis B, 15% to 40% will develop serious sequelae during their lifetime.
Definitions
ÎChronic hepatitis B: Chronic necroinflammatory disease of the liver caused by persistent infection with HBV. Chronic hepatitis B can be subdivided into hepatitis B e antigen (HBeAg) positive and HBeAg negative chronic hepatitis B.
ÎInactive HBsAg carrier state: Persistent HBV infection of the liver without significant, ongoing necroinflammatory disease.
ÎResolved hepatitis B: Previous HBV infection without further virologic, biochemical or histological evidence of active virus infection or disease.
ÎAcute exacerbation or flare of hepatitis B: Intermittent elevations of aminotransferase activity to more than 10 times the upper limit of normal and more than twice the baseline value.
ÎReactivation of hepatitis B: Reappearance of active necroinflammatory disease of the liver in a person known to have the inactive HBsAg carrier state or resolved hepatitis B.
ÎHBeAg clearance: Loss of HBeAg in a person who was previously HBeAg positive.
ÎHBeAg seroconversion: Loss of HBeAg and detection of anti-HBe (antibody to ABeAg) in a person who was previously HBeAg positive and anti-HBe negative.
ÎHBeAg reversion: Reappearance of HBeAg in a person who was previously HBeAg negative, anti-HBe positive.
