My son aged 3 years 11 months weighing 11.6kg is having fever for the last 4 days. He was administered P250 3.5ml every 6 hrs, Frisium 5mg 1/2 tablet every 12 hours , meftol 3.5ml whenever the fever shoots up. Today routine blood test and urine test was done. Notable points are ESR 32mm/hr, monocyte 0 %, Basophil )%, Neutrophil Poly 59%, Pus cells 2-4, Eithelial cells 1-2 /Hpf. Other parameters are within normal limits. BacigylN 3ml every 12 hours and Econorm every 12 hours were administered to him from yesterday. What might be the reason for the fever ? From today he is fine and the temperature is normal.