Hepatitis B: Screening, Prevention, Diagnosis, and Treatment.

Hepatitis B virus (HBV) is a partly double-stranded DNA virus that causes acute and chronic liver infection. Screening for hepatitis B is recommended in pregnant women at their first prenatal visit and in adolescents and adults at high risk of chronic infection. Hepatitis B vaccination is recommended for medically stable infants weighing 2,000 g or more within 24 hours of birth, unvaccinated infants and children, and unvaccinated adults requesting protection from hepatitis B or who are at increased risk of infection. Acute hepatitis B is defined as the discrete onset of symptoms, the presence of jaundice or elevated serum alanine transaminase levels, and test results showing hepatitis B surface antigen and hepatitis B core antigen. There is no evidence that antiviral treatment is effective for acute hepatitis B. Chronic hepatitis B is defined as the persistence of hepatitis B surface antigen for more than six months. Individuals with chronic hepatitis B are at risk of hepatocellular carcinoma and cirrhosis, but morbidity and mortality are reduced with adequate treatment. Determining the stage of liver disease (e.g., evidence of inflammation, fibrosis) is important to guide therapeutic decisions and the need for surveillance for hepatocellular carcinoma. Treatment should be individualized based on clinical and laboratory characteristics and the risks of developing cirrhosis and hepatocellular carcinoma. Immunologic cure, defined as the loss of hepatitis B surface antigen with sustained HBV DNA suppression, is attainable with current drug therapies that suppress HBV DNA replication and improve liver inflammation and fibrosis. Pegylated interferon alfa-2a, entecavir, and tenofovir are recommended as first-line treatment options for chronic hepatitis B.