title: AIDS: Definition, overview, and "new" virus.
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000453:epidemiology / Q000209:etiology* / Q000635:transmission; D000328:Adult; D000349:Africa; D000818:Animals; D002522:Chlorocebus aethiops; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012306:Risk; D014481:United States