For persons with acute hepatitis, testing should be performed to differentiate among types of viral hepatitis.
Acute hepatitis A
Immunoglobulin M antibody to hepatitis A virus (IgM anti-HAV)-positive
Acute hepatitis B
IgM antibody to hepatitis B core antigen (IgM anti-HBc)-positive; and hepatitis B surface antigen (HBsAg)-positive
Acute hepatitis C
Serum alanine aminotransferase levels more than seven times the upper limit of normal;
	and
Antibody to hepatitis C virus (anti-HCV) positive (repeat reactive) by screen ing immunoassay, and confirmed by a more specific assay (e.g., recombinant immunoblot assay [RIBA] for anti-HCV or nucleic acid testing for HCV RNA)
	or
Anti-HCV-positive (repeat reactive) by screening immunoassay and a signal- to-cutoff ratio predictive of a true positive as determined for the particular assay (e.g., 3.8 for screening enzyme immunoassay).
Laboratory tests for diagnosis of chronic hepatitis:
Chronic hepatitis B virus infection
HBsAg-positive, total anti-HBc-positive, and IgM anti-HBc-negative,
	or
HBsAg-positive two times six months apart
Chronic hepatitis C virus infection
Anti-HCV-positive (as defined above) and HCV RNA-positive six months apart