An acute illness with a) discrete onset of symptoms and b) jaundice
or elevated serum aminotransferase levels
Laboratory criteria for diagnosis:
Hepatitis A: immunoglobulin
M (IgM) antibody to hepatitis A virus (anti-HAV) positive
Hepatitis B:
IgM antibody to hepatitis B core antigen (anti-HBc) positive
or hepatitis B surface antigen (HBsAg) positive
IgM anti-HAV negative (if done)
Hepatitis C:
Serum aminotransferase levels greater than 2.5 times
the upper limit of normal, and
IgM anti-HAV negative, and
IgM anti-HBc negative (if done) or HBsAg negative, and
Antibody to hepatitis C virus (anti-HCV) positive, verified
by a supplemental test
Non-A, Non-B hepatitis:
Serum aminotransferase levels greater than 2.5 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 (if done)
Delta hepatitis*: HBsAg or IgM anti-HBc positive
and antibody to hepatitis delta virus 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 in a person who has an epidemiologic link
with a person who has laboratory-confirmed hepatitis A (i.e., household or sexual
contact with an infected person during the 15-50 days before the onset of symptoms)
Comment
Persons who have chronic hepatitis or persons identified
as HBsAg positive or anti-HCV positive should not be reported as having acute
viral hepatitis unless they have evidence of an acute illness compatible with
viral hepatitis (with the exception of perinatal hepatitis B infection). (See
Hepatitis, Viral, Perinatal Hepatitis B Virus Infection Acquired in the United
States or U.S. Territories.)
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 because some
(5%-10%) have not yet seroconverted and others (5%-10%) remain negative even
with prolonged follow-up (6).
Available serologic tests for anti-HCV do not distinguish
between acute and chronic or past infection. Thus, other causes of acute hepatitis
should be excluded for anti-HCV positive patients who have an acute illness
compatible with viral hepatitis.
* Delta Hepatitis is not a nationally
notifiable disease.
References
6. Kuo G, Choo Q-L, Alter HJ, et al. An assay for circulating antibodies to a major
etiologic virus of human non-A, non-B hepatitis. Science 1989;244:362-4.