My 3 year old grandson has been running a high fever since last Monday, February 15 it s been as high as 104.6, it lowers when he takes ibuprofen, but goes right back up when it starts to wear off! Has a cough now and then, diarrehea 2 times daily x2 days, chills, tired! Has been seen by 2 doctors, strep test negative, ears clear, lungs clear, his sinus seems to be very plugged, very nasal sounding when he talks! He is a little might, poor eater! Very worried about him! Should he be swabbed for Influenza?