title: National surveillance of viral hepatitis, 1981.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D005260:Female; D006525:Hepatitis, Viral, Human / Q000453:epidemiology* / Q000635:transmission; D006801:Humans; D008297:Male; D008875:Middle Aged; D014481:United States