For severe respiratory illness , at Denver hospital , urgent care , says official . Missouri doctor calls it ` ` unprecedented '' in terms of kids in intensive care . ` ` This is the worst I ' ve seen in my time , '' a Denver doctor says . Enterovirus D68 ( EV - D68 ) causes respiratory illness like a cold , only worse .
900 severe respiratory illness cases at Denver hospital , urgent care , says official . Missouri doctor calls situation `` unprecedented '' in terms of kids in intensive care . `` This is the worst I 've seen in my time , '' a Colorado doctor says . Enterovirus D68 ( EV-D68 ) causes respiratory illnesses like a cold , only worse .