A patient is found to be positive only for Anti HBsAg. All other viral markers are negative.The likely diagnosis is :
Answer is A (Vaccination) Isolated Anti-HBs Ag in serum is seen in immunization with HB.s Ag. Possible Causes of Isolated Anti-HBsAg Positivity in serum (Other markers negative) Immunization with HBsAg (after vaccination) Hepatitis B in the remote past (?) False-positive
Vaccination
Chronic hepatitis B
Acute hepatitis B
Fulminant hepatitis B