Initial Testing Bundle: - Order HBsAg, anti-HBc, and anti-HBs Then follow the HBsAg result: *1. If HBsAg is Positive* : - Order IgM anti-HBc - If IgM anti-HBc is positive → _Acute HBV Infection_ - If IgM anti-HBc is negative → _Chronic HBV Infection_ - For chronic infection, order additional tests: * HBeAg * HBV DNA * LFTs (Liver Function Tests) * Liver fibrosis assessment *2. If HBsAg is Negative:* Check anti-HBc status: A. If anti-HBc is Positive: - Check anti-HBs - If anti-HBs positive → _Resolved HBV Infection_ - If anti-HBs negative → _Four possible interpretations:_ 1. _Resolved infection_ 2. _False positive anti-HBc_ 3. _'Low level' chronic infection_ 4. _Window period_ B. If anti-HBc is Negative: - Check anti-HBs - If anti-HBs positive → _Immune due to vaccination_ - If anti-HBs negative → _Susceptible (candidate for vaccination)_ This systematic approach helps determine the patient's Hepatitis B status and appropriate next steps in management.