Table 1 Definitions and terms used in hepatitis B virus infection.

	Definition	Diagnosis
Acute hepatitis B	Acute hepatic injury that develops within 6 months after exposure to the virus and resolves within 6 months after onset of symptoms	HBsAg (+) ↑↑↑ ALT/AST ↑↑↑ IgM anti‐HBc
Chronic hepatitis B	Chronic necroinflammatory disease of the liver caused by HBV	HBsAg (+) for >6 months Serum HBV DNA (+) (>105 copies/ml) ↑ ALT/AST (persistently or intermittently) Chronic hepatitis in liver biopsy (necroinflammatory score ⩾ 4)* HBeAg ±†
Inactive HBsAg carrier state	Chronic HBV infection characterised by:	HBsAg (+) for > 6 months HBeAg (−)/Anti‐HBe (+) Persistently normal ALT/AST (serial testing for 1 year) Serum HBV DNA levels (<105 copies/ml) (serial testing for 1 year) Absent or minimal liver necroinflammation in liver biopsy (necroinflammatory score < 4)*
Resolved HBV infection		HBsAg (−) Serum HBV DNA (−) Normal ALT levels Known history of acute/chronic hepatitis B or anti‐HBc (+)/anti‐HBs±
Occult HBV infection		HBsAg (−) HBV DNA (+) in serum/liver Anti‐HBc ±, Anti‐HBs±

Adapted from Lok and McMahon and de Franchis et al.¹²,¹³

*Optional; †HBeAg (+) = HBeAg positive chronic hepatitis B or HBeAg (−) = HBeAg negative chronic hepatitis B.

HBsAg, hepatitis B surface antigen; ALT, alanine aminotransferase; AST, aspartate aminotransferase; anti‐HBc, antibody to hepatitis B core antigen; HBV, hepatitis B virus; HBeAg, hepatitis B e antigen; anti‐HBe, antibody to hepatitis B e antigen.