title: Letter: Parenteral versus non-parenteral transmission of HBAg.
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D004196:Disease Outbreaks / Q000453:epidemiology; D006509:Hepatitis B / Q000453:epidemiology / Q000209:etiology* / Q000276:immunology; D006511:Hepatitis B Antigens / Q000302:isolation & purification*; D006801:Humans; D007106:Immune Sera / Q000032:analysis; D005779:Immunodiffusion; D012383:Romania
chemical_list: D006511:Hepatitis B Antigens; D007106:Immune Sera