An acute illness with a) discrete onset of symptoms and b) jaundice
or elevated serum aminotransferase levels.
Laboratory Criteria for Diagnosis:
Hepatitis A: IgM anti-HAV positive
Hepatitis B:
IgM anti-HBc-positive (if done) or HBsAg-positive, and
IgM anti-HAV negative (if done)
Hepatitis C:
Serum aminotransferase levels >2 and 1/2 times the
upper limit of normal, and
IgM anti-HAV negative, and
IgM anti-HBc negative (if done) or HBsAg negative, and
Anti-HCV positive
Non-A, Non-B Hepatitis:
Serum aminotransferase levels >2 and 1/2 times the
upper limit of normal, and
IgM anti-HAV negative, and
IgM anti-HBc negative (if done) or HBsAg-negative, and
Anti-HCV negative or not done
Delta Hepatitis*: HBsAg or IgM anti-HBc positive
and anti-HDV-positive
Case Classification
Confirmed: 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.
Comment
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.