4 months old male child came with fever, irritability since 2 days. Infant was feeding well till then. There was h/o third dose of DPT/Polio given 2 days back. Was given Paracitamol. Next day fever & irritability continued coupled with refusal to feed. On examination : Temp. 99degF, Heart rate 110 per min. , RR 40, AF being narrow could not be well appreciated. ENT – Normal, Per abdomen – Soft, Liver 1cm palpable – firm, Spleen not palpable, Baby was then admitted & put on maintenance I.V. fluids. CBC showed : Hb 11.3, WBC 10100, N49, E2, L49, Low Platelets of 63000.Smear for Malaria parasite negative. Fever subsided but irritability & refusal to feed continued for next day. Repeat CBC on second day of admission showed Hb 11.1, WBC 8300, N36, E5, L56, M3, Platelets dropping further to 55000, Serum Proteins 7.9 with albumin 3.6 , SGPT 385, PT 14 with control 14, PTT 39 with control 29, Serum Electrolytes : Na 145, K 5.2, Cl 109. Child is haemodynamically stable with good urine output. What is the probable diagnosis and further line of treatment?