Hepatitis B
Laboratory confirmation requires at least one of the following:

• HBsAg positive in an infant aged under 12 months
• change from HBsAg negative to HBsAg positive within a 12-month period (if testing is performed at the same laboratory and the cumulative history is readily available within the laboratory information systems)
• anti-HBcore IgM reactive (unless HBsAg positive more than 6 months ago and the history is readily available in laboratory information systems)
• detection of hepatitis B virus (HBV) nucleic acid.

Hepatitis C
Laboratory confirmation requires positive anti-HCV serology or detection of HCV nucleic acid.

Hepatitis NOS
Laboratory definitive evidence for a confirmed case requires negative tests for hepatitis A and C, and one of:

• a positive anti-HDV test or detection of HDV nucleic acid
• a positive anti-HEV test or detection of HEV nucleic acid
• a positive test for hepatitis G.

Hepatitis D requires simultaneous hepatitis B co-infection; testing for hepatitis D is indicated in clinically severe cases of suspected hepatitis B.