Key Facts

Bacterial meningitis remains one of the most important emergencies in paediatrics. Despite declining incidence due to vaccination, it carries significant mortality and morbidity. Rapid recognition and treatment are the key determinants of outcome.

Epidemiology

Bacterial meningitis incidence in UK children has declined significantly since MenC, Hib, PCV, and MenB vaccination. Current incidence: ~5-10 per 100,000 children. MenB remains the most common cause of meningococcal disease in the UK (despite MenB vaccine). Peak incidence: <1 year and 15-19 years.

Aetiology

By age:

• Neonates: GBS, E. coli, Listeria
• 1 month-5 years: N. meningitidis, S. pneumoniae, Hib (rare post-vaccine)
• >5 years: N. meningitidis, S. pneumoniae

Viral meningitis (much more common than bacterial): Enterovirus (most common), HSV-2, mumps, parechovirus.

Pathophysiology

Bacteria reach the meninges via haematogenous spread (most common), direct extension (skull fracture, sinusitis), or ascending infection. In the subarachnoid space, bacteria multiply rapidly due to low levels of complement and immunoglobulins in CSF. The inflammatory response (cytokines, leukocyte infiltration) causes cerebral oedema, increased ICP, reduced cerebral blood flow, and neuronal injury.

Infants (<1 year)

• Non-specific: Irritability, lethargy, poor feeding, vomiting, fever or hypothermia
• Bulging fontanelle (late sign)
• High-pitched cry
• Neck stiffness often ABSENT
• Seizures

Older Children

• Fever, headache, photophobia
• Neck stiffness (Kernig's sign, Brudzinski's sign)
• Altered consciousness
• Vomiting, irritability
• Non-blanching rash (meningococcal — petechial → purpuric)

Meningococcal Septicaemia

• Petechial/purpuric rash — non-blanching
• Rapid deterioration — septic shock
• DIC — bleeding, purpura fulminans
• May occur WITH or WITHOUT meningitis

Red Flags

• Non-blanching rash with fever — give antibiotics IMMEDIATELY (do NOT wait for LP or results)
• Altered consciousness (GCS <12) — raised ICP; CT before LP
• Seizures — increased morbidity
• Rapid pulse rate, prolonged CRT, cool peripheries — septic shock
• Signs of raised ICP — papilloedema, altered consciousness, Cushing's response

Bedside

• Blood glucose: Before LP (compare with CSF glucose)
• Observations: Sepsis screening — HR, RR, BP, CRT, temperature, GCS

Bloods

• Blood culture: Before antibiotics (but do NOT delay antibiotics)
• FBC, CRP, procalcitonin: Inflammatory markers
• Coagulation: DIC screen
• U&Es: SIADH (hyponatraemia) common in meningitis
• Blood gas: Lactate, pH
• Meningococcal PCR: If blood culture negative

LP (CSF Analysis)

• Contraindications to LP: Signs of raised ICP (CT first), haemodynamic instability, coagulopathy, local infection
• CSF findings:

Imaging

• CT head: Before LP if signs of raised ICP, focal neurology, or GCS <9
• MRI brain: If complications suspected (abscess, subdural empyema, venous sinus thrombosis)

Immediate

• Do NOT delay antibiotics for LP or imaging if bacterial meningitis suspected
• IV ceftriaxone 80mg/kg (max 4g) — start immediately
• Add IV amoxicillin if <3 months (Listeria cover)
• IV dexamethasone 0.15mg/kg QDS: Give before or with first antibiotic dose; continue for 4 days if bacterial meningitis confirmed

Supportive

• Fluid management: Avoid fluid overload (SIADH risk); maintenance fluids initially; reassess frequently
• Seizure management: Buccal midazolam or IV lorazepam per APLS protocol
• Monitoring: Neuro obs, fluid balance, electrolytes, GCS
• PICU: For septic shock, raised ICP, respiratory failure

Duration of Antibiotics

• Meningococcal: 7 days
• Pneumococcal: 14 days
• GBS (neonatal): 14-21 days
• Gram-negative (neonatal): 21 days

Public Health

• Notify: All cases of meningococcal disease to PHE
• Chemoprophylaxis: Ciprofloxacin (adults) or rifampicin (children) for household and kissing contacts of meningococcal disease

Referral Criteria

• All suspected bacterial meningitis — admit, antibiotics immediately
• Septic shock — PICU
• Complications (subdural empyema, hydrocephalus, brain abscess) — neurosurgery

• Bacterial meningitis mortality: ~5-10% in children (higher in neonates and meningococcal septicaemia)
• Long-term sequelae: ~25% — hearing loss (most common), neurodevelopmental impairment, epilepsy, hydrocephalus, limb amputation (meningococcal)
• Dexamethasone: Reduces hearing loss (NNT 14 for pneumococcal meningitis)
• Viral meningitis: Excellent prognosis; full recovery expected
• Post-discharge: Audiology within 4 weeks; neurodevelopmental follow-up

CSF Analysis Summary

Contact Prophylaxis for Meningococcal Disease