Hello I have gone through your complaints. Initially your child has viral infection which can be through air or through water. But now as your child is developing
cough with high grade
fever with shivering, there may be associated secondary bacterial infection. You have done a good job by sending swab.
Diaper rash can be due to
contact dermatitis. It can also be due to ammonitis due to contact with urine and stool. Please check every 2nd hourly whether your child passed urine and then change the diaper. It's better you avoid diaper for few days. Apply rash free cream twice a day.
Thank you. Good day