Researchers in Delhi, India, investigated the prevalence of bacterial meningitis in 497 children aged 6-18 months admitted to hospital with a first seizure with fever. Lumbar puncture was performed in 199 (40%) infants; 116 with “simple” seizures and 83 “complex.” (The hospital has a policy of LP in all patients with complex febrile seizures). Meningitis was diagnosed in 5 infants (2.4%); 1 (0.86%) with simple, and 4 (4.81%) with complex features. Risk factors for meningitis included 1) duration of seizure >30 min; 2) postictal drowsiness; and 3) neurological deficits, the most reliable indicator. The mean age was 12.2 months and 12.9 months in patients with and without meningitis, respectively. CSF findings with meningitis were as follows: mean cell count 73.8 mm3; protein 92.6 g/dl; glucose 51.2 g/dl; all cultures were sterile, probably due to prior antibiotics. Blood cultures showed no bacteremia. In 2 patients with meningitis, cause of fever was not identified. Most common causes of fever in the total cohort were URI infection, gastritis, pneumonia, and otitis media. [1]

COMMENT. The authors conclude that lumbar puncture may be indicated in children aged 6-18 months who present with a first seizure with fever, especially if the seizure lasts > 30 minutes, there is postictal drowsiness, or most specifically, there are neurological deficits. The diagnosis of meningitis was made without identifying an organism in 2 patients, and the organism identified was not specified in the remaining 3 cases. Although the CSF gram stain and culture were considered the gold standard for a diagnosis of meningitis, the diagnosis was based mainly on the CSF cell count, protein, and sugar.

Normative CSF profiles of febrile infants, aged 1 to 90 days, with negative bacterial culture and negative PCR for enteroviral infection, were studied at University of Utah, Salt Lake City [2]. In 677 infants with atraumatic LP, the mean and median CSF WBC were 4.3/mm3 and 3.0/mm3, respectively, with a range from 0 to 12/mm3. CSF WBC counts were higher in the first month vs months 2 and 3; 6.1 v 3.1 and 3.0, respectively. Protein levels were 75.4 mg/dl vs 58.9 and 39.2, respectively.(P<0.001 for all). CSF glucose levels were lower in the first month compared to month 3; 45.3 mg/dl vs 57.7 mg/dl (P<0.001). Normal CSF WBC counts in febrile infants 1 to 90 days are lower than reported in pediatric references.