This bacterial meningitis in children calculator provides criteria for the diagnosis of bacterial meningitis and delimitation from aseptic causes. In the text below the tool, there is in depth information on the criteria used and also the score interpretation.


Blood absolute neutrophil count 10,000 cells/mm3 or more


Gram stain of CSF positive


CSF Protein more than 80 mg/dL


Incidence of seizures with illness


Spinal fluid neutrophil count ≥ 1000 cells/mm3

How does this bacterial meningitis in children calculator work?

This health tool aims to help with the diagnosis of bacterial meningitis in children and as well differentiate when meningitis sings are present but consistent with aseptic meningitis.

There are 5 criteria in the bacterial meningitis in children calculator, each requiring a positive or negative answer which contributes to the final score:

■ Blood absolute neutrophil count 10,000 cells/mm3 or more – This is a measure of neutrophil granulocytes (PMNs) that are one of the white blood cells that fight against infection. Their increase is significant with infectious disease.

■ Gram stain of CSF positive – primary culture from cerebrospinal fluid allows identification of bacterial meningitis, i.e. with Neisseria. CSF gram stain is used in pediatric bacterial meningitis stratification, however the rate of false positives needs to be taken in consideration as 40% of cases may be due to contamination or misinterpretation.

■ CSF Protein more than 80 mg/dL – cerebrospinal fluid normal characteristics include a volume of up to 150 mL, osmolarity of 281 mOsm/L, pH between 7.28 and 7.32 and proteins between 15 – 40 mg/dL. Different levels of spinal tap carry different results i.e. Ventricular 15 – 25 mg/dL , however  the range remains valid. High levels of protein in CSF indicate meningitis, brain abscesses, cerebral hemorrhage or neurosyphilis.

■ Incidence of seizures with illness – anticonvulsants might be required to prevent seizures.

■ Spinal fluid neutrophil count ≥ 1000 cells per cubic mm, following the blood ANC, any increase in white blood cells from CSF is indicative of meningitis.

Score interpretation

Each of the five items weights a number of points in the final score, 4 of them weight 1 point while CSF positive weights 2 points. The minimum score obtainable is 0 while the maximum is 6.

A score of 0 points shows that diagnosis of bacterial meningitis is unlikely, however, if symptoms are consistent with meningitis presentation, the possible existence of aseptic meningitis should be investigated.

Scores of one evidence that bacterial cause diagnosis becomes likely, but still not enough information to delineate between bacterial and aseptic meningitis.

Scores between 2 and 6 indicate a high likelihood of positive diagnosis for bacterial meningitis for the pediatric patient.

Bacterial meningitis medical guidelines

Meningitis is characterized by inflammation of the meninges and as a clinical syndrome, presentation consists of the triad: fever, headache and neck stiffness.

Other symptoms include nausea, photophobia, sleepiness, irritability or vomiting. In the most severe causes, confusion and coma follows.

In infants, presentation might include bulging fontanelle, jaundice, paradoxic irritability, hypotonia or high pitched cry.

Aseptic or viral meningitis is more common than bacterial one, it is easier to treat and has a lower risk of leaving sequels. Children and young adults are at higher risk of infection because of the hours they spend in close communities. Routine vaccinations are available against meningococcal disease (i.e. MCV4).

Bacteria and viruses spreading through the blood stream can reach the cerebrospinal fluid or can be localized there after severe infections (otitis media, sinusitis) or head trauma.

Laboratory diagnosis include lumbar puncture, CBC (complete blood count), serum and CSF glucose, serum electrolytes, blood urea nitrogen. Laboratory diagnosis is accompanied by examination of meningeal irritation, level of consciousness and focal neurologic signs.

Complications of the bacterial kind can lead to serious neurological impairment, hearing or visual loss or seizures.


1) Nigrovic LE, Kuppermann N, Malley R. (2002) Development and validation of a multivariable predictive model to distinguish bacterial from aseptic meningitis in children in the post-Haemophilus influenzae era. Pediatrics; 110(4):712-9.

2) Neuman MI, Tolford S, Harper MB. (2008) Test characteristics and interpretation of cerebrospinal fluid gram stain in children. Pediatr Infect Dis J; 27(4):309-13.

3) Murthy JM, Prabhakar S. (2008) Bacterial meningitis and epilepsy. Epilepsia; 49 Suppl 6:8-12.

4) Mehl AL. (1986) Interpretation of traumatic lumbar puncture. A prospective experimental model. Clin Pediatr (Phila); 25(10):523-6.

15 May, 2016