Accuracy of Clinical and Cerebrospinal Fluid Indicators in the Diagnosis of Bacterial Meningitis in Infants

Abstract

The diagnosis of bacterial meningitis (BM) is problematic in young infants, as clinical features may be nonspecific or even absent. Cerebrospinal fluid (CSF) analysis usually confirms the diagnosis, but the CSF parameters can be normal also in culture-proven BM. Our objective was to identify the clinical and CSF indices, that quickly and without laboratory likely lead to the diagnosis of confirmed of probable BM in young infants in Angola. We conducted a prospective, observational, single-site study from February 2016 to October 2017 in the Pediatric Hospital of Luanda. All assessed infants showed symptoms and signs compatible of BM or neonatal sepsis and were <90 days of age. Of the 1088 infants, 212 (19%) showed bacteria in CSF, while 88 (8%) had probable BM. Independent clinical indicators of BM were not-clear CSF, seizures, weight <2500 g and illness >7 days. In infants with BM, CSF leukocytes were >10 × 106/L in 46%, CSF glucose <25 mg/dL in 43% and CSF protein >120 mg/dL in 58%. All measured parameters were in normal range in 25% of patients. In 515 infants with normal CSF parameters, bacteria were found in 74 (14%). In these infants, illness >7 days, weight <2500 g and malnutrition increased the probability of BM. Our study confirms and underlines the problems in diagnosing BM in young infants. While the CSF parameters were normal in 25% of infants, the easily recognizable unclear appearance of CSF was the single strongest predictor of BM.