Thank you for your query on Healthcare Magic.
Fever of 15 days duration should be investigated appropriately.
Investigations like CBP, CUE, Malarial parasite, widal test
, urine for culture to be done to know the focus of infection.
Cold and cough may be due to frequent upper respiratory tract
infections or due to some allergic conditions.
Ear ache will occur in association with the cold but ear has to be examined using a otoscope to look for any middle ear infection
Consult your Pediatrician
again for re evaluation and for treatment.
Hope I have answered your query.