Clinical Prediction Rule for Distinguishing Bacterial From Aseptic Meningitis

Santiago Mintegi, PhD,a Silvia García, PhD,a María José Martín, MD,c Isabel Durán, MD,d Eunate Arana-Arri, PhD, Scientific Coordination Unit, Biocruces Bizkaia Health Research Institute, Cruces University Hospital, Osakidetza, Bilbao, Basque Country, Spain,e Catarin et al

PEDIATRICS Volume 146, number 3, September 2020:e20201126

BACKGROUND:

New biomarkers like procalcitonin and C-reactive protein may help design an accurate decision support tool used to identify children with pleocytosis at low or high risk of bacterial meningitis. Our objective was to develop and validate a score (that we call the meningitis score for emergencies [MSE]) to distinguish bacterial meningitis from aseptic meningitis in children with pleocytosis when initially evaluated at the emergency department.

METHODS:

We included children between 29 days and 14 years old with meningitis admitted to 25 Spanish emergency departments. A retrospective cohort from between 2011 and 2016 was used as the derivation set and a prospective cohort recruited during 2017 and 2018 was used as the validation set.

RESULTS:

Among the 1009 patients included, there were 917 cases of aseptic meningitis and 92 of bacterial meningitis. Using multivariable logistic regression analysis,

we identified the following predictors of bacterial meningitis from the derivation set:

procalcitonin .1.2 ng/mL,

cerebrospinal fluid (CSF) protein .80 mg/dL,

CSF absolute neutrophil count .1000 cells per mm3, and

C-reactive protein .40 mg/L.

Using the derivation set, we developed the MSE, assigning 3 points for procalcitonin, 2 points for CSF protein, and 1 point for each of the other variables. An MSE 1 or morepredicted bacterial meningitis with a sensitivity of 100% (95% confidence interval [CI]: 95.0%–100%), a specificity of 83.2 (95% CI: 80.6–85.5), and a negative predictive value of 100% (95% CI 99.4–100.)

CONCLUSIONS

MSE accurately distinguishes bacterial from aseptic meningitis in children with CSF pleocytosis. The inclusion of procalcitonin and CRP improves the performance of the BMS. The MSE can be used to guide initial clinical decision-making in children with CSF pleocytosis without misclassifying children with bacterial meningitis.