"Problem/Condition: In the United States, acute viral hepatitis most frequently is caused by infection with three viruses: hepatitis A virus (HAV), hepatitis B virus (HBV), and hepatitis C virus (HCV). These unrelated viruses are transmitted through different routes and have different epidemiologic profiles. Safe and effective vaccines have been available for hepatitis B since 1981 and for hepatitis A since 1995. No vaccine exists against hepatitis C. Reporting Period Covered: Cases in 2006, the most recent year for which data are available, are compared with those from previous years. Description of System: Cases of acute viral hepatitis are reported voluntarily to CDC by state and territorial epidemiologists via CDC's National Notifiable ...