title: Hepatitis B antigen. Icidence in school children.
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D006506:Hepatitis A / Q000453:epidemiology* / Q000276:immunology; D006511:Hepatitis B Antigens / Q000032:analysis; D006801:Humans; D008875:Middle Aged; D012383:Romania; D012572:School Health Services; D014505:Urban Population
chemical_list: D006511:Hepatitis B Antigens