Neonatal meningitis

Related Subjects: |Lumbar Puncture |CSF Interpretation |CSF Rhinorrhoea

👶🧠 Neonatal meningitis – Definitive diagnosis is made by CSF examination via lumbar puncture (LP). LP should be performed in any neonate suspected of sepsis/meningitis, but ⚠️ treatment must not be delayed while awaiting results.

📖 About

• Occurs within the first 90 days of life 🍼.
• Most often bacterial, and is a life-threatening emergency 🚨.

🩺 Clinical Presentation

• ⚠️ Classical triad (fever, stiff neck, vomiting) often absent.
• Instead look for:
  • ❌ Poor feeding, irritability, lethargy
  • 😴 Apnoea, listlessness, reduced tone
  • 🌡️ Fever OR hypothermia
  • ⚡ Seizures
  • 🚩 Other red flags: bulging fontanelle, high-pitched cry, hypoglycaemia, metabolic acidosis, shock, pallor

🦠 Microbiology

• Group B Streptococcus (GBS) 🧬 → ~50% (esp. type III; vertical transmission).
• Escherichia coli (K1 capsule) 🦠 → ~20%.
• Listeria monocytogenes 🥗 → 5–10% (contaminated food in pregnancy).
• Viruses 🦠 → HSV, VZV (less common, but important for prognosis).

⚠️ Complications

• ♿ Cerebral palsy (~8%)
• 📘 Learning disability (~7%)
• ⚡ Persistent seizures (~7%)
• 👂 Hearing loss (~25%)
• 🧠 Hydrocephalus, abscess, or subdural effusion

👶➡️👧 Causes in Older Infants (>3 months)

• Streptococcus pneumoniae 🧬
• Neisseria meningitidis 💉
• Haemophilus influenzae type b (Hib) 💊 (much less common since vaccination).

💊 Management

• 🚑 Immediate IV antibiotics (before LP if unstable):
  • Ampicillin + Cefotaxime (UK NICE guidance) 💉
  • Avoid ceftriaxone in neonates (risk of kernicterus) ❌
• 💧 Supportive care: fluids, oxygen, seizure control (phenobarbital/levetiracetam).
• 🦠 If HSV suspected: add Acyclovir 🧪
• 🔊 Hearing test follow-up (due to high risk of deafness).
• 🧪 Close monitoring: blood cultures, CSF studies, CRP trends.
• 👩‍👦 Public health: maternal screening & prophylaxis for GBS at delivery reduces risk.

🧑‍🏫 Exam Tip

Neonatal meningitis is one of the few conditions where the common organisms differ significantly from older children. Always think GBS, E. coli, and Listeria 👶 - whereas after 3 months, pneumococcus and meningococcus dominate.

Cases - Neonatal Meningitis

• Case 1 - Early-onset GBS infection 🍼: A 3-day-old term infant presents with poor feeding, irritability, and fever. Exam: bulging fontanelle, lethargy. CSF: neutrophilia, low glucose, high protein. Blood culture: Group B Streptococcus. Diagnosis: early-onset neonatal meningitis (GBS). Managed with IV benzylpenicillin + gentamicin, then tailored antibiotics.
• Case 2 - E. coli meningitis 🦠: A 10-day-old preterm baby develops temperature instability, seizures, and poor tone. Mother had prolonged rupture of membranes. CSF: Gram-negative bacilli, low glucose, high protein. Culture: E. coli K1. Diagnosis: neonatal meningitis due to E. coli. Managed with IV cefotaxime for 21 days.
• Case 3 - Listeria infection 🥛: A 14-day-old infant presents with poor feeding, apnoea, and irritability. Mother ate unpasteurised cheese during pregnancy. CSF: mononuclear predominance, positive Gram-positive bacilli. Diagnosis: Listeria monocytogenes meningitis. Managed with IV ampicillin + gentamicin.

Teaching Point 🩺: Neonatal meningitis is most often caused by Group B Strep, E. coli, or Listeria. - Early onset (<7 days): GBS, E. coli, Listeria (maternal transmission). - Late onset (>7 days): same organisms + nosocomial Gram-negatives. Presents non-specifically (poor feeding, irritability, temperature instability, seizures). Management: urgent IV antibiotics + supportive care. Mortality and neurological sequelae remain high.