beginning in the latter part of 1985 , 2,047 gay and bisexual men who were enrolled in the pitt men 's study , the pittsburgh cohort of the multicenter aids cohort study ( macs ) , were invited by mail to learn the results of their antibody test for hiv infection -- human immunodeficiency virus infection .
C0001175
aids
C0019693
human immunodeficiency virus infection