An acute illness with a) discrete onset of symptoms and b) jaundice or elevated serum aminotransferase levels.
A case that meets the clinical case definition and is laboratory confirmed; or for hepatitis A, a case that meets the clinical case definition and occurs among a contact of a person who has a laboratory-confirmed case.
Do not report cases among persons who have chronic hepatitis or persons identified as HBsAg- or anti-HCV positive as being cases of acute viral hepatitis without evidence of an acute illness compatible with viral hepatitis (with the exception of perinatal hepatitis B virus infection [see Hepatitis, Viral, Perinatal Hepatitis B Virus Infection Acquired in the United States or U.S. Territories]). Furthermore, up to 20% of acute hepatitis C cases will be anti-HCV negative when reported and will be classified as non-A, non-B hepatitis; approximately 10% of cases are anti-HCV negative during the acute phase of illness because of a prolonged interval between onset of disease and seroconversion, and an additional 10% are anti-HCV negative even with prolonged follow-up, because the sensitivity of the antibody assay is only 90%. The only serologic test routinely available for the diagnosis of hepatitis C is total anti-HCV; therefore, excluding other causes of the acute hepatitis is necessary. * Delta Hepatitis is not a nationally notifiable disease.