Acute bacterial meningitis.

Despite improvements in antibiotic therapy and the use of vaccines and chemoprophylaxis, acute bacterial meningitis remains a significant cause of morbidity and mortality in the United States. Early diagnosis and therapy are important once the condition has been considered and the appropriate available specimens collected. Changes in epidemiologic frequencies and antimicrobial susceptibilities suggest that therapy will become more uniform across all age groups. Rapid, specific diagnostic modalities for all etiologic agents and improved vaccines for Neisseria meningitidis type B and Streptococcus pneumoniae are urgently needed.