I think you need to get him back to your pediatrician. If its a serologic test that was done, most of the time its not very sensitive nor specific. Ideal tests like stool cultures and blood cultures cool yield more conclusive results. a reevaluation by your pediatrician is an option, to may be run more tests and consider other differential diagnosis for this high fever. Rememebr also that, persistence of fever one day after discharge does not mean that the treatmemnt has failed.
Take care

Hello Vers,
Before a fever in a child we should rule out different possibilities, in my country we always start by eliminating:
malaria ( with thick blood film)
urinary tract infection (urinalysis)
typhoid fever (widal test)
acute otitis media (otoscopy)
gastroenteritis ( watery/soft frequent stool, do a stool exams)
respiratory tract infection ( symptoms of airway tract infection should be present and work-up done)
septicemia/sepsis (blood culture, complete blood count etc)
others: neoplasia, abscess etc

In summary, the above are the different diagnosis to eliminate before a fever in a child. So i will advise you revisit your pediatrician for complete reevaluation of the child to come out with any of the above diagnosis.

Wish you baby a good health and a quick recovery

Hi,
Thanks for posting your query.
Negative result for dengue fever & typhoid fever, with persistence of fever suggest another cause of all symptoms.
Let me know the symptoms along with fever & vomiting.
Does he has watery shit with spasmodic abdominal pain?
You should again consult with the treating doctor and should go for ultrasound imaging.
At times in childhood, fever with vomiting may be a preliminary symptoms of impending appendicitis.
Hope for speedy recovery.
Take care,
Dr. Mayank Bhargava

go for other investigations for fever and platelet dont decrease in all cases. do other tests to rule out dengue such as elisa and NS1 ag. high grade intermittent fever with vomiting may also be suggestive of malaria. so rule out these first and then go for further investigations