Neonatal bacterial meningitis and dexamethasone adjunctive usage in Nigeria

Neonatal bacterial meningitis is devastating, with attendant high mortality and neurological sequelae. We, therefore, aimed to delineate its current incidence, etiologic, clinical, laboratory spectra, and the effect of steroid therapy on the outcome.

Babies admitted from 1992 to 1995 in the Special Care Baby Unit of the University of Maiduguri Teaching Hospital, Maduguri, Nigeria, with bacterial meningitis were studied prospectively. Neonatal bacterial meningitis was confirmed if the cerebrospinal fluid (CSF) microbiological, chemical, immunological and clinical criteria were satisfied. Detailed neurological follow-up was made.

Sixty-nine cases of neonatal bacterial meningitis were encountered, (25 were early-onset, and 44 late-onset); the incidence was 6.5/1000 live births. 22 Positive CSF cultures were grown in early-onset meningitis, and 28 in late-onset disease. Low birth weight showed higher risk of bacterial meningitis and it was significantly more likely in the preterm. X2 = 24.19, p = 0.000001). Gram-negative pathogens were more isolated (28/50, 56%); Escherichia coli (11) being the commonest, while of the Gram-positive pathogens Staphylococcus aureus was most predominant overall (13/50). Concomitant blood culture was positive in 39/50 (78%), inclusive of all 22 "definite" early-onset disease. The CSF WBC was minimally raised (25-30 x 10(6)/L) in 11 (22%) of "definite" neonatal bacterial meningitis. Detection of unusual pathogens was noteworthy: N. meningitidis (2) and H. influenzae (2), contributing 0.6 and 2.2 per 1000 live births and admissions, respectively. Overall mortality was 24.6%. Of the forty survivors, 9 (22.5%) had neurological sequelae: sensorineural hearing deficit (3), hydrocephalus (2), subdural effusion (2), hemiparesis (1), afebrile (recurrent) seizure (1), and there was reduced developmental quotients at 24 months follow-up in 33. Dexamethasone therapy decreased mortality significantly; p = 0.0004.

The new information highlighted by this research includes the lack of Group B Streptococcus isolation, the finding of S. pneumoniae, N. meningitidis, H. influenzae and S. aureus as significant pathogens, usefulness of blood cultures in the detection of neonatal bacterial meningitis, increasing resistance of Gram-positive neonatal pathogens to cloxacillin, low CSF WBC, and the finding that the adjunctive use of dexamethasone significantly decreases case fatality and neurological sequelae.