Bacterial meningitis ; neonatal meningitis ; Haemophilus influenzae ; group B ; streptococci ; Streptococcus pneumoniae ; Neisseria meningitidis
Abstract
Purpose : We investigated the causative organisms of bacterial meningitis by age distribution from 1996 to 2005.
Methods : Retrospective data were obtained from the medical records with diagnosis of bacterial meningitis or neonatal meningitis from 1996 through 2005. A case was defined by isolation of organism or detection of its antigen by latex agglutination from cerebrospinal fluid.
Results : A total of 46 cases(27 neonates and 19 children) were identified. 15 of 27 episodes(55.6%) of neonatal meningitis had a concomitant-positive blood culture. Group B streptococci were the most common bacterial causes of neonatal meningitis(44.4%). Nine of 12 episodes(75.0%) were late-onset infections in neonatal meningitis caused by group B streptococci. 16 of 19 children(84.2%) with bacterial meningitis beyond the neonatal period were younger than 5 years of age(median age, 23 months). Of 19 cases, 8 infections were with Streptococcus pneumoniae, 8 were with Haemophilus influenzae and 3 were with Neisseria meningitidis. Since 2001 there was no case of meningococcal meningitis in this study.
Conclusion : In neonates group B streptococci are the most common causative organisms of bacterial meningitis, especially late-onset infections. In infants and young children, the predominant causes of bacterial meningitis are H. influenzae and S. pneumoniae; meningitis caused by the former are likely to decrease after the introduction of the conjugate vaccine for H. influenzae type b.