Meningitis - Acute, Bacterial (Pediatric)

Definition

Acute bacterial meningitis in children is a rapidly progressive infection of the meninges, typically caused by bacterial pathogens, leading to inflammation of the brain and spinal cord coverings. It is a medical emergency due to potential neurological complications and mortality.

Epidemiology

• Highest incidence in children under 5 years, especially infants under 1 year
• Neonates at higher risk due to immature immune system
• Seasonal peaks in winter and early spring for certain pathogens
• Common bacterial pathogens vary with age: Group B Streptococcus and E. coli in neonates, Streptococcus pneumoniae and Neisseria meningitidis in older children
• Vaccination has reduced incidence of Haemophilus influenzae type b (Hib) and pneumococcal meningitis

Etiology

• Neonates: Group B Streptococcus, Escherichia coli, Listeria monocytogenes
• Infants and children: Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae type b
• Post-surgical or trauma-related: Staphylococcus aureus, coagulase-negative staphylococci
• Immunocompromised children may be susceptible to Gram-negative bacilli and fungal pathogens

Pathophysiology

• Bacteria invade the bloodstream and cross the blood-brain barrier
• Inflammatory response in meninges causes increased vascular permeability and cerebral edema
• Release of cytokines and bacterial toxins leads to neuronal injury
• Increased intracranial pressure may result in brain herniation
• Impaired CSF flow can cause hydrocephalus
• Complications include seizures, hearing loss, and long-term neurological deficits