Content Source:
Office of Public Health Data, Surveillance, and Technology
Hepatitis C, Chronic
2020 Case Definition
Hepatitis C, Chronic
2020 Case Definition
2020 Case Definition
CSTE Position Statement(s)
- 19-ID-06
Clinical Criteria
All hepatitis C virus cases in each classification category should be > 36 months of age, unless known to have been exposed non-perinatally.
One or more of the following:
- Jaundice, OR
- Peak elevated total bilirubin levels ≥ 3.0 mg/dL, OR
- Peak elevated serum alanine aminotransferase (ALT) levels >200 IU/L,
AND
The absence of a more likely diagnosis (which may include evidence of acute liver disease due to other causes or advanced liver disease due to pre-existing chronic Hepatitis C virus (HCV) infection or other causes, such as alcohol exposure, other viral hepatitis, hemochromatosis, etc.)
Laboratory Criteria
Confirmatory laboratory evidence:
- Positive hepatitis C virus detection test: Nucleic acid test (NAT) for HCV RNA positive (including qualitative, quantitative, or genotype testing), OR
- A positive test indicating presence of hepatitis C viral antigen(s) (HCV antigen)
Presumptive laboratory evidence:
- A positive test for antibodies to hepatitis C virus (anti-HCV)
Epidemiologic Linkage
No epidemiologic linkage is required for case classification.
Criteria to Distinguish a New Case from an Existing Case
All jurisdictions are encouraged to track negative HCV viral detection tests to document both spontaneous clearance of infection or sustained viral response to HCV treatment. Cases that have evidence of having cleared the infection at time of initial report or are considered false positive should not be reported to CDC.
If evidence indicating resolution of infection is received after a confirmed chronic case has been reported to CDC, the case report does not need to be modified as it was a confirmed case at the time of initial report. However, negative HCV viral detection test results received on confirmed chronic cases, subsequent to an initial positive result, should be appended to case reports, as feasible, and considered for the purpose of data analysis by each jurisdiction.
Evidence for re-infection may include a case of confirmed chronic HCV infection that has at least two sequential negative HCV viral detection tests reported, indicative of treatment initiation and sustained virologic response, followed by a positive HCV viral detection test. Under current treatment recommendations, those two negative tests should be at least three months apart, however, the timing may change as standard of care for HCV treatment evolves. Other evidence of reinfection should be considered, including a report of a new genotype on a case that has previously cleared a different genotype. Jurisdictions are encouraged to ensure that cases of HCV treatment failure are not classified as new cases of HCV infection to the extent that it can be determined. Jurisdictions tracking re-infection should also consider collecting data on prior treatment completion (when relevant and possible to document), treatment failure, change in reported genotype if that applies, and the known time frame for reinfection.
For probable chronic cases, the presence of a negative HCV viral detection test result, in the absence of criteria that would allow for confirmation, indicates that a case should not be classified as probable chronic and should not be reported to CDC.
A new chronic case is a newly reported case that does not have evidence of being an acute case of HCV infection. A confirmed acute case may be classified as a confirmed chronic case if a positive HCV viral detection test is reported one year or longer after acute case onset. A confirmed acute case may not be reported as a probable chronic case (i.e. HCV antibody positive, but with an unknown HCV viral detection test). For purposes of incidence and prevalence calculations, confirmed chronic HCV cases should be counted.
Jurisdictions are also encouraged to track and classify possible re-infection cases that may have been previously submitted to CDC as a confirmed or probable chronic HCV infection case. Jurisdictions tracking re-infection should also consider collecting data on prior treatment completion (when relevant and possible to document), treatment failure, change in reported genotype if that applies, and the known time frame for reinfection.
Case Classification
Suspect
NUL
Probable
- A case that does not meet OR has no report of clinical criteria,
AND - Has presumptive laboratory evidence,
AND - Has no documentation of anti-HCV or RNA test conversion within 12 months,
AND - Does not have an HCV RNA detection test reported.
Confirmed
- A case that does not meet OR has no report of clinical criteria,
AND - Has confirmatory laboratory evidence,
AND - Has no documentation of anti-HCV or HCV RNA test conversion within 12 months.