Hepatitis C

2000 Case Definition

Clinical case definition

An acute illness with a) discrete onset of symptoms (such as nausea, vomiting, abdominal pain and diarrhea) and b) jaundice or abnormal serum aminotransferase levels

Laboratory criteria for diagnosis

Serum alanine aminotransferase levels greater than 7 times the upper limit of normal,

and

IgM antibody to hepatitis A virus (IgM anti-HAV) negative (if done)

and

IgM antibody to hepatitis B core antigen (IgM anti-HBc) negative, or if not done, hepatitis B surface antigen (HBsAg) negative,

and

Antibody to hepatitis C virus (anti-HCV) positive, verified by an additional more specific assay.

Case classification:

Confirmed: a case that meets the clinical case definition and is laboratory confirmed

Comment:

• Persons who have chronic hepatitis or persons identified as anti-HCV positive should not be reported as having acute viral hepatitis unless they have evidence of an acute illness compatible with viral hepatitis.
• 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.

See also:

• 2004 Case Definition for Hepatitis C, Acute

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.