Brief Answer:
Thorough investigation is needed

Detailed Answer:
Hello

Thanks for the query


Recurrent persistent fever should be investigated thoroughly.
You have mentioned that she is otherwise healthy that means she does not have any cough,cold,abdominal pain,vomiting,loose stool,visual disturbances,urinary problem,joint pain or rashes as absence of these symptoms rules out any local infection in most of the cases.
I assume that she has been clinically examined by the pediatrician and no abnormality is detected.
In the absence of any clue in history and clinical examination,investigations are the only thing which can help.
The high grade fever in the absence of any symptoms ca be due to unusual infection,autoimmune disorder and rarely due to hematological malignancy.
Urinary tract infection is a common cause of fever even in the absence of any urinary symptoms.

I would like to get some investigations done like Hemogram,ESR,CRP,Procalcitonin,blood culture,hepatic transaminases,urine routine examination and culture sensitivity,test for malaria,monospot test (for infectious monoinucleosis)brucella serology(particulary if contact with animal is there) and chest Xray.

If all these tests are normal then investigations like USG abdomen(to search any hidden abscess),ANA(to rule out autoimmune disorder),bone marrow examination(for hematological disorder or to see any infective organism in the marrow),echocardiography(to rule out infection of the heart valve ).
Emperical antibiotic treatment should be started after sending all these investigation in view of any suspected unusual infection.

In small number of cases even after all these investigation the cause can not be found out.But then at least with the help of these investigation we can exclude all serious and treatable disease.

I hope this helps.
Please be in follow up about the further proceedings and if possible attach the reports so that I better able to help you out.

Wish your child speedy recovery.
Regards

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