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Hepatitis, Viral, Acute
1995 Case Definition
Clinical Case Definition
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.
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