Children with fever should be tested for influenza A and B.

A comprehensive and thorough examination for children with fever to check for influenza A and B should include: General examination: appearance assessment, palpation, and physical examination; Laboratory tests: blood cell count, complete blood count, liver function tests, blood biochemistry, and urinalysis; Imaging studies: X-ray, blood gas analysis, electroencephalography (EEG), magnetoencephalography (MEG), and ultrasound; Antibody testing: specific antibody tests for influenza A and B; Molecular diagnostics: viral nucleic acid testing, serological analysis, etc. Further investigations, depending on the clinical situation, may include chest computed tomography (CT), pulmonary perfusion studies, electrocardiogram (ECG), cerebrospinal fluid examination, etc.