In general neutrophils are abnormal in pediatric CSF and should increase the suspicion for bacterial<unk> <unk> can also occur in children with normal CSF microscopy.
If the CSF is abnormal the safest course is to treat as if it is bacterial<unk> until cultures return negative growth.'
Infants with aseptic<unk> should still be admitted given still at high risk of dehydration and neurologic sequelae
PCR is available for Neisseria meningitidis, Herpes Simplex and Enterovirus and will with inpatient diagnosis.  PCR is most helpful for patients with encephalitis and has poor sensitivity and specificity for bacterial antigens.
0 points: Aseptic<unk> likely
1 point: Aseptic<unk> less likely
≥2 points:  Bacterial<unk> more likely
CSF cultures are negative 2 hrs after parenteral antibiotics in meningococcal<unk>  and 6 hrs in pneumococcal<unk> 12 hrs after antibiotics: CSF glucose levels increase and protein levels decrease. CSF WBC and neutrophils are not affected
Meningitis 
Upper respiratory infection 
Encephalitis
UTI
Meningoencephalitis
Sepsis
Neoplastic meningitis
Meningitis