2 yrs old boy with fever and severe drop of neutrophils from 900 to 450 within 2 days,wbc 2,4, he is in hospital now for check up.what can cause this severe drop,covid negative,small lung infection also,no other symptoms??is there a risk on his life?

Neutrophils are part of the bodies defense against infection. A drop in the total count means there is decreased production or they are being used up too fast by some process. The sign is worrisome. The best persons to respond to the life risk question is the treatment team that know all the history/exam and test results.

Please provide the differential count, including percentages and type of cells e.g. lymphocytes. A respiratory panel is recommended by obtaining a sample of the nasal secretions. Influenza, RSV and adenovirus should be considered. If not improving, re test for COVID. Are there chest image results? A virtual consultation with Healthtap is available. The support desk may be able to fwd results2 me.