The epidemiology of viral hepatitis in the United States.

Hepatitis types A, B, and C are the most important forms of viral hepatitis in the Unites States. High-risk sexual and drug use behavior have been associated with epidemics of hepatitis A and endemic transmission of both hepatitis B and hepatitis C. Immune globulin preparations and vaccines have been developed that effectively prevent hepatitis A and hepatitis B. In the absence of such preventive measures, the prevention of hepatitis C will depend on a better understanding of the host and environmental factors that facilitate transmission of this disease.