title: AIDS infection rate falls among Brazil's injection drug users.
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000150:complications / Q000453:epidemiology* / Q000517:prevention & control; D001938:Brazil / Q000453:epidemiology; D015528:HIV Seroprevalence / Q000639:trends*; D006801:Humans; D008297:Male; D015819:Substance Abuse, Intravenous / Q000150:complications*