MY NEPHEW AGED 20 YEARS HAS BEEN HAVING SEVERE HEADACHE,VOMITING,PAINS IN THE LEGS,AND FEVER SINCE 2 DAYS .YESTERDAY HIS TEMP WAS 102 F AND HE WAS VERY WEAK AND SEEMED TO BE HIGHLY DEHYDRATED .WAS ADMITTED IN UNIV.HOSPITAL(SMALL).HE WAS GIVEN SOME I.V FLUIDS AND PARACETAMOL TABLETS.VOMITING STOPPED ,FEVER CAME DOWN TO 99F ,LEG PAINS DECREASED BUT HEADACHE CONTINUES TO BE SEVERE TODAY. HIS VIDAL TEST IS +VE I.E. 1:320 . ALL OTHER TEST ARE NORMAL,HE HAS BEEN PUT ON CEFEXIME 200 MG TAB. TDS AND 6 HOURLY .IN ADDITION TO 1 ULTRA CET TABLET AT 9:AM ,1 TRAMEDOL INJECTION AT 5.30 PM AND NEXDOM 500 MG TAB. AT 11.30 PM. PLEASE SUGGEST RIGHT DIAGNOSIS AND TREATMENT