ated ▁the ▁first ▁out break ▁of ▁E bol a ▁in ▁Z aire ▁( with ▁Peter ▁Pi ot , ▁Karl ▁Johnson , ▁Jo el ▁Bre man , ▁Joe ▁McC orm ick ▁amongst ▁others ) ▁and ▁the ▁first ▁out break ▁of ▁Leg ion naire ' s ▁D ise ase , ▁in ▁Philadelphia . ▁ ▁Career ▁He ym ann ▁was ▁appointed ▁Chair man ▁of ▁the ▁Board ▁of ▁the ▁UK ▁Health ▁Prote ction ▁Agency ▁( HP A ) ▁in ▁April ▁ 2 0 0 9 . ▁He ▁remained ▁Chair man ▁of ▁the ▁Board ▁when ▁H PA ▁was ▁merged ▁into ▁Public ▁Health ▁England ▁( P HE ) ▁in ▁ 2 0 1 3 . ▁At ▁the ▁same ▁time , ▁he ▁started ▁and ▁became ▁Head ▁and ▁Senior ▁Fellow ▁of ▁the ▁Centre ▁on ▁Global ▁Health ▁Security ▁at ▁Ch ath am ▁House , ▁London ▁( the ▁Royal ▁Institute ▁of ▁International ▁Affairs ) ▁and ▁in ▁ 2 0 1 0 ▁joined ▁the ▁fac ulty ▁at ▁the ▁London ▁School ▁of ▁H yg iene ▁and ▁Trop ical ▁Medicine ▁as ▁Professor ▁of ▁In fect ious ▁D ise ase ▁Ep ide mi ology . ▁ ▁He ym ann ▁was ▁the ▁World ▁Health ▁Organ ization ' s ▁( W HO ) ▁Ass istant ▁Director - General ▁for ▁Health ▁Security ▁and ▁Environment ▁and ▁the ▁representative ▁of ▁the ▁Director - General ▁for ▁Pol io ▁er adic ation . ▁Pre viously , ▁from ▁ 1 9 9 8 – 2 0 0 3 , ▁he ▁was ▁Executive ▁Director ▁of ▁the ▁W HO ▁Communic able ▁D ise ases ▁Cl uster ▁and