Prophylaxis for hepatitis A.

Hepatitis A is a common communicable disease in this country. Each diagnosed case of hepatitis A involves the problem of selecting contacts for post-exposure immunoglobulin. These decisions should be systematic, based on current knowledge of epidemiology, kinetics of viral excretion by infected persons and the influence of time on the efficacy of immunoglobulin prophylaxis. An algorithm incorporates this information into a strategy consistent with the United States Public Health Service guidelines.