Pneumococcal meningitis ✅

🧠 Pneumococcal meningitis is a life-threatening bacterial meningitis caused by Streptococcus pneumoniae. 👥 Contacts: routine chemoprophylaxis is not indicated for close contacts of isolated pneumococcal meningitis ❌ - unlike meningococcal disease. 🌟 Key differentiator: there is usually no characteristic purpuric rash, although any septic patient can occasionally develop non-specific skin signs.

📖 About

• Streptococcus pneumoniae is a Gram-positive, lancet-shaped, encapsulated diplococcus.
• It is one of the most important causes of bacterial meningitis in adults in the UK.
• The polysaccharide capsule helps the organism evade phagocytosis. Especially in patients with impaired splenic function.
• Infection often follows nasopharyngeal colonisation, with spread from the bloodstream or from adjacent infection such as otitis media, mastoiditis or sinusitis.
• Compared with meningococcal meningitis, pneumococcal meningitis has a higher risk of death and long-term neurological disability.

⚠️ Risk Factors

• Older age and frailty.
• Alcohol excess, chronic liver disease or chronic lung disease.
• Asplenia or hyposplenia, including sickle cell disease.
• Immunocompromise: HIV, haematological malignancy, chemotherapy, transplant or long-term immunosuppression.
• CSF leak, skull fracture, previous neurosurgery or cochlear implant.
• Recent otitis media, mastoiditis, sinusitis or pneumonia.
• Incomplete pneumococcal vaccination in high-risk groups.

🩺 Clinical Features

• Classic meningitis features: fever, severe headache, neck stiffness and photophobia.
• Brain dysfunction: confusion, reduced consciousness, agitation, seizures or focal neurological signs.
• Systemic illness: vomiting, myalgia, tachycardia, hypotension or septic shock.
• Rash: a purpuric non-blanching rash is not typical and should make meningococcal disease more likely.
• Older adults may present atypically with delirium, falls, reduced oral intake or general deterioration rather than classical meningism.

🧬 Pathophysiology

• Pneumococcus reaches the subarachnoid space via bacteraemia or direct extension from ENT infection.
• The capsule reduces opsonisation, allowing survival in blood and CSF.
• In the CSF, bacterial cell wall components trigger a marked inflammatory cytokine response.
• This causes blood-brain barrier disruption, cerebral oedema, raised intracranial pressure and reduced cerebral perfusion.
• Dexamethasone is used early because it reduces the inflammatory response triggered when antibiotics lyse bacteria.

🚨 Complications

• Sensorineural hearing loss - a common and important complication.
• Seizures or status epilepticus.
• Cerebral oedema and raised intracranial pressure.
• Hydrocephalus.
• Stroke, cerebral venous sinus thrombosis or focal neurological deficit.
• Cognitive impairment, memory problems and neurodisability.
• Sepsis, septic shock and multi-organ failure.

🧪 Investigations

• Blood cultures: take immediately, but do not delay antibiotics.
• FBC: neutrophilia may be present; thrombocytopenia suggests severe sepsis.
• CRP, U&E, LFT, clotting, glucose and lactate: assess severity and guide resuscitation.
• Paired blood glucose: required to interpret CSF glucose accurately.
• CT head before LP if there are features suggesting raised intracranial pressure or mass lesion, such as:
  • Focal neurological deficit.
  • New-onset seizure.
  • Significantly reduced or deteriorating GCS.
  • Papilloedema.
  • Signs of brain shift or immunocompromise where an intracranial lesion is possible.
• LP/CSF: opening pressure may be raised; neutrophils ↑, protein ↑, glucose ↓, lactate ↑.
• Gram stain: may show Gram-positive diplococci.
• CSF culture and PCR: confirm organism and guide antibiotic narrowing.
• ENT imaging/input: consider if otitis media, mastoiditis, sinusitis or CSF leak is suspected.

💊 Management

• 🚨 Medical emergency: treat immediately - do not wait for CT or LP if these will delay antibiotics.
• Empirical IV antibiotics: follow local policy; in UK practice this is commonly IV ceftriaxone or cefotaxime.
• Add amoxicillin/ampicillin if Listeria risk is present, especially age over 60, pregnancy or significant immunocompromise.
• Confirmed pneumococcal meningitis: continue high-dose IV ceftriaxone or cefotaxime, adjusted to sensitivities and microbiology advice.
• Resistance concern: add vancomycin ± rifampicin on microbiology advice, particularly if cephalosporin resistance is suspected.
• Dexamethasone: give before or with the first antibiotic dose where possible; continue if pneumococcal meningitis is confirmed or strongly suspected.
• Usual adult regimen: dexamethasone 10 mg IV every 6 hours for 4 days, or weight-based dosing in children according to local/NICE guidance.
• Supportive care: oxygen, IV fluids, glucose control, antipyretics, seizure treatment and early critical care involvement if reduced GCS, shock or respiratory compromise.
• Monitor for raised intracranial pressure and avoid hypotension, hypoxia and hyponatraemia.

👥 Contacts & Public Health

• Routine antibiotic prophylaxis for household or healthcare contacts is not usually required for isolated pneumococcal meningitis.
• This contrasts with meningococcal disease, where close contacts may require urgent chemoprophylaxis.
• Clusters of invasive pneumococcal disease are unusual; if suspected, discuss with microbiology, infection prevention and the local Health Protection Team.
• Review pneumococcal vaccination status in the patient and consider whether an underlying risk factor such as asplenia, CSF leak or immunodeficiency is present.

💉 Prevention

• Pneumococcal vaccination reduces invasive pneumococcal disease.
• UK vaccination includes pneumococcal conjugate vaccine in childhood and pneumococcal polysaccharide vaccine for older adults and selected high-risk groups.
• High-risk groups include asplenia, CSF leak, cochlear implant, chronic kidney disease, chronic heart/lung/liver disease, diabetes and immunosuppression.

📌 Clinical Pearls

• Think pneumococcus in an older adult with meningitis, especially with pneumonia, otitis media, sinusitis, alcohol excess or asplenia.
• No purpuric rash helps distinguish it from meningococcal disease, but absence of rash never excludes bacterial meningitis.
• Do not delay antibiotics for CT or LP - blood cultures first, then immediate treatment.
• Give dexamethasone early: it works best when given before or with the first antibiotic dose.
• Always consider hearing loss after recovery and arrange appropriate follow-up.

📚 References

• NICE NG240: Bacterial meningitis and meningococcal disease - recognition, diagnosis and management.
• BNF/NICE: Central nervous system infections, antibacterial therapy.
• UKHSA: Guidance on invasive pneumococcal disease and pneumococcal vaccination.
• Local NHS antimicrobial guideline - always check local resistance patterns and dosing policy.