CDC Acute Hepatitis C Case Definition
Clinical case definition:
An acute illness with a discrete onset of any sign or symptom consistent with acute viral hepatitis (e.g., anorexia, abdominal discomfort, nausea, vomiting), and either jaundice or serum alanine aminotransferase (ALT) levels >400 IU/L.
Laboratory criteria for diagnosis:
One or more of the following three criteria:
Antibodies to hepatitis C virus (anti-HCV) screening test positive with a signal to cut-off ratio predictive of a true positive as determined for the particular assay as defined by CDC, OR
Hepatitis C Virus Recombinant Immunoblot Assay (HCV RIBA) positive, OR
Nucleic Acid Test (NAT) for HCV RNA positive
and, meets the following two criteria:
IgM antibody to hepatitis A virus (IgM anti-HAV) negative, AND
IgM antibody to hepatitis B core antigen (IgM anti-HBc) negative
Confirmed: A case that meets the clinical case definition, is laboratory confirmed, and is not known to have chronic hepatitis C.
Abbreviations: CDC, Centers for Disease Control and Prevention; HAV, hepatitis A virus; HCV, hepatitis C virus; RIBA, recombinant immunoblot assay; RNA, ribonucleic acid.
NOTE: URL for the signal-to-cutoff ratios: http://www.cdc.gov/ncidod/diseases/hepatitis/c/sc_ratios.htm.
SOURCE: CDC, 2009a.