The diagnosis of hepatitis C is relatively simple and is based on detection of anti-HCV through enzyme-linked immunoassays (EIA) that are both sensitive http://www.ncbi.nlm.nih.gov/pubmed/25053704 and specific. The EIA now in use represents a third generation of this assay and consists of recombinant viral protein cores, NS3 and NSS regions of the viral genome in a solid phase assay. The presence of anti-HCV appearance of anti-HCV may be delayed a few weeks after HCV RNA following acute infection.
A liver biopsy would show features of acute rather than chronic hepatitis but is not routinely recommended. The diagnosis of acute hepatitis C cannot be made with certainty unless the patient was known to be HCV negative previously and then developed HCV RNA in serum with or without clinical features of acute hepatitis.