▁med ics , ▁have ▁happened ▁in ▁the ▁days ▁that ▁preced ed ▁the ▁launch ▁of ▁the ▁alert ▁and ▁came ▁out ▁only ▁in ▁these ▁days ▁due ▁to ▁a ▁massive ▁back log . ▁ ▁By ▁May ▁ 5 , ▁ 2 0 0 9 , ▁the ▁number ▁had ▁ris en ▁to ▁ 4 0 3 ▁and ▁a ▁second ▁death ▁was ▁reported ▁in ▁Texas . ▁The ▁CD C ▁and ▁government ▁officials ▁had ▁expressed ▁c aut ious ▁optim ism ▁about ▁the ▁sever ity ▁and ▁spread ▁of ▁H 1 N 1 . ▁ ▁Ch anges ▁in ▁surve ill ance ▁of ▁cases ▁of ▁influen za - like ▁ill ness , ▁including ▁new ▁gu idel ines ▁for ▁ident ifying ▁cases ▁to ▁test , ▁increased ▁labor atory ▁testing , ▁and ▁new ▁test ▁k its ▁able ▁to ▁distinguish ▁this ▁novel ▁stra in , ▁resulted ▁in ▁a ▁sp ike ▁in ▁the ▁percent ▁of ▁cases ▁tested ▁positive ▁for ▁influen za . ▁ ▁Of ▁the ▁positive ▁cases , ▁about ▁a ▁third ▁were ▁due ▁to ▁the ▁novel ▁stra in . ▁ ▁Also ▁found ▁were ▁a ▁substantial ▁number ▁of ▁cases ▁where ▁the ▁stra in ▁could ▁not ▁be ▁sub ty ped . ▁ ▁The ▁proportion ▁of ▁US ▁death s ▁due ▁to ▁p neum onia ▁and ▁influen za ▁clim bed ▁above ▁the ▁ep ide mic ▁threshold ▁in ▁the ▁ 2 0 0 7 – 2 0 0 8 ▁winter ▁flu ▁season ▁but ▁not ▁in ▁the ▁ 2 0 0 8 – 2 0 0 9 ▁season . ▁ ▁Although ▁the ▁ 2 0 0 9 ▁H 1 N 1 ▁out