inal ▁ill ness . ▁ ▁Despite ▁the ▁earlier ▁publication ▁of ▁path ogen ic ▁variants ▁of ▁E . ▁col i , ▁research ers ▁encountered ▁significant ▁difficulties ▁in ▁establish ing ▁E TE C ▁as ▁a ▁path ogen . ▁ ▁Human ▁imm un ode fic iency ▁virus ▁( 1 9 5 9 - 1 9 8 4 ) ▁ ▁A ID S ▁was ▁first ▁reported ▁June ▁ 5 , ▁ 1 9 8 1 , ▁when ▁the ▁U . S . ▁Cent ers ▁for ▁D ise ase ▁Control ▁and ▁Pre vention ▁recorded ▁a ▁cluster ▁of ▁P neum oc yst is ▁car ini i ▁p neum onia ▁( now ▁still ▁class ified ▁as ▁P CP ▁but ▁known ▁to ▁be ▁caused ▁by ▁P neum oc yst is ▁j iro ve cii ) ▁in ▁five ▁hom osex ual ▁men ▁in ▁Los ▁Angeles . ▁The ▁discovery ▁of ▁the ▁virus ▁took ▁several ▁years ▁of ▁research , ▁and ▁was ▁announced ▁in ▁ 1 9 8 4 ▁by ▁Dr . ▁Gal lo ▁of ▁the ▁National ▁Can cer ▁Institute , ▁Dr . ▁Luc ▁Mont agn ier ▁at ▁the ▁P aste ur ▁Institute ▁in ▁Paris , ▁and ▁Dr . ▁Jay ▁Le vy ▁at ▁the ▁University ▁of ▁California , ▁San ▁Francisco . ▁ ▁However , ▁H IV ▁existed ▁long ▁before ▁the ▁ 1 9 8 1 ▁CD C ▁report . ▁Three ▁of ▁the ▁earliest ▁known ▁instances ▁of ▁H IV ▁in fection ▁are ▁as ▁follows : ▁A ▁pl asma ▁sample ▁taken ▁in ▁ 1 9 5 9 ▁from ▁an ▁adult ▁male ▁living ▁in ▁what ▁is ▁now ▁the