Prevalence.  CDC report:  1.1 million Americans infected with HIV.
D002487:Centers for Disease Control and Prevention, U.S.; D005260:Female; D015658:HIV Infections / Q000453:epidemiology* / Q000635:transmission; D006801:Humans; D008297:Male; D015995:Prevalence; D012307:Risk Factors; D014481:United States / Q000453:epidemiology