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NOTE: A surveillance case definition is a set of uniform criteria used to define a disease for public health surveillance. Surveillance case definitions enable public health officials to classify and count cases consistently across reporting jurisdictions. Surveillance case definitions are not intended to be used by healthcare providers for making a clinical diagnosis or determining how to meet an individual patient’s health needs.

CSTE Position Statement(s)

  • 10-ID-09

Clinical Description

No symptoms are required. Most hepatitis C virus (HCV)-infected persons are asymptomatic; however, many have chronic liver disease, which can range from mild to severe.

Laboratory Criteria For Diagnosis

One or more of the following four criteria:

  • Antibodies to hepatitis C virus (Anti–HCV) positive (repeatedly reactive) by enzyme immunoassay (EIA) verified by at least one additional more specific assay, OR
  • Hepatitis C virus recombinant immunoblot assay (HCV RIBA) positive, OR
  • Nucleic acid test (NAT) positive for HCV RNA (including genotype), OR
  • Anti-HCV screening-test-positive with a signal to cut-off ratio predictive of a true positive as determined for the particular assay and posted by CDC. (

Case Classification


A case that is anti-HCV positive (repeat reactive) by EIA and has alanine aminotransferase (ALT or serum glutamic pyruvic transaminase [SGPT]) values above the upper limit of normal, but the anti-HCV EIA result has not been verified by an additional more specific assay or the signal to cut-off ratio is unknown.


A case that is laboratory confirmed and does not meet the case definition for acute hepatitis C.

Related Case Definition(s)