Prevalence of hepatitis B antigen.
D000367:Age Factors; D000906:Antibodies / Q000032:analysis; D002353:Carrier State; D006506:Hepatitis A / Q000276:immunology*; D006511:Hepatitis B Antigens / Q000032:analysis*; D006801:Humans
D000906:Antibodies; D006511:Hepatitis B Antigens