Key Points
����An estimated 350 million persons worldwide are chronically infected
with the hepatitis B virus (HBV).
����In 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.
����Carriers of HBV are at increased risk of developing cirrhosis, hepatic
decompensation, and hepatocellular carcinoma (HCC).
����Although most carriers will not develop hepatic complications from
chronic hepatitis B, 15% to 40% will develop serious sequelae during
their lifetime.
Definitions
����Chronic 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.
����Inactive HBsAg carrier state: Persistent HBV infection of the liver
without significant, ongoing necroinflammatory disease.
����Resolved hepatitis B: Previous HBV infection without further virologic,
biochemical or histological evidence of active virus infection or
disease.
����Acute 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.
����Reactivation 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.
����HBeAg clearance: Loss of HBeAg in a person who was previously
HBeAg positive.
����HBeAg seroconversion: Loss of HBeAg and detection of anti-HBe
(antibody to ABeAg) in a person who was previously HBeAg positive
and anti-HBe negative.
����HBeAg reversion: Reappearance of HBeAg in a person who was
previously HBeAg negative, anti-HBe positive.
