Acute and chronic viral hepatitis.

Hepatitis A, B, C, D, E, and G are important causes of viral hepatitis. It is estimated that there are at least 32,000 new cases of hepatitis A, 300,000 new cases of hepatitis B, and 150,000 new cases of hepatitis C each year in the United States alone. Risk factors for hepatitis infection include sexual activity with multiple partners, intravenous drug use or sharing cocaine straws, tattooing or body piercing, exposure to blood and body fluids through health-care work, and having a blood transfusion or transplant.

Evaluation of tests used to screen patients with liver disorders.

There is no one test of liver function. Routine laboratory tests that are useful in screening for liver disease and following its course include serum AST, ALT, alkaline phosphatase, protein electrophoresis, prothrombin time, and bilirubin levels. The transaminase levels give a day-by-day account of the amount of hepatocellular injury and death that occurs.