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Meningitis - bacterial meningitis and meningococcal disease
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Exam Tips
- In OSCEs, treat suspected bacterial meningitis/meningococcal disease as a 'give antibiotics now' emergency: investigations must not delay first dose.
- The classic red-flag cluster is fever + headache + neck stiffness + altered cognition, but infants and older adults may lack one or more features.
- A non-blanching rash with sepsis signs is meningococcal disease until proven otherwise; check the whole skin surface including hidden areas.
- CSF pattern for bacterial meningitis: neutrophils high, protein high, glucose low relative to serum; quote this clearly in written exams.
- Always mention contraindications/safety: avoid benzylpenicillin in true anaphylaxis history, avoid delaying treatment for LP/CT in unstable patients, and involve public health for contact prophylaxis.
- Image recall for exams: see standard teaching figure of meningococcal petechiae-to-purpura evolution and meningeal layer anatomy (commonly used in paediatric infection lectures).
Definition
Bacterial meningitis is an acute infection of the leptomeninges and cerebrospinal fluid that can rapidly progress to raised intracranial pressure, cerebral injury, and death if treatment is delayed. Meningococcal disease is invasive infection due to Neisseria meningitidis and may present as meningitis, septicaemia, or both; in UK practice, both conditions are medical emergencies and legally notifiable.
Pathophysiology
Nasopharyngeal colonization (commonly by Neisseria meningitidis or Streptococcus pneumoniae) precedes bloodstream invasion, then traversal of the blood-brain barrier into CSF. Because CSF has limited opsonization and complement activity, organisms multiply quickly, triggering intense cytokine-driven inflammation (for example TNF-alpha, IL-1), blood-brain barrier breakdown, vasculitis, cerebral oedema, impaired perfusion, and risk of infarction. Meningococcal disease additionally causes endotoxin-mediated capillary leak, coagulopathy, purpura fulminans, and shock. In neonates, common pathogens are group B streptococcus, E. coli, and other coliforms, with immature host immunity increasing vulnerability.
Risk Factors
- Age under 2 years (especially infants under 1 year)
- Adolescence/young adulthood (higher meningococcal carriage and transmission)
- Age over 65 years
- Asplenia or hyposplenism (including sickle cell disease)
- Complement deficiency or complement inhibitor therapy
- Immunocompromise (for example HIV, chemotherapy)
- Incomplete vaccination (MenB, MenACWY, pneumococcal, Hib where indicated)
- Crowded living (for example student halls), smoking, winter season
- Recent close contact with meningococcal or Hib disease, or outbreak exposure
- Cranial anatomical defect, CSF leak, cochlear implant
- Contiguous ENT/chest infection (otitis media, sinusitis, mastoiditis, pneumonia)
- Previous bacterial meningitis, malignancy, significant liver/kidney dysfunction
Clinical Features
Symptoms
- Fever (may be absent in very young infants and older adults)
- Severe headache
- Neck pain or stiffness
- Photophobia
- Nausea/vomiting
- Altered mental state (confusion, delirium, drowsiness)
- Limb pain, myalgia, cold extremities (early meningococcal sepsis)
- Poor feeding, irritability, high-pitched cry in infants
Signs
- Reduced Glasgow Coma Scale or fluctuating consciousness
- Meningism (neck stiffness; Kernig/Brudzinski may be absent early)
- Non-blanching petechial or purpuric rash (suggestive of meningococcal disease)
- Bulging fontanelle in infants with open fontanelle
- Signs of sepsis/shock: tachycardia, tachypnoea, prolonged capillary refill, hypotension
- Seizures
- Focal neurology or cranial nerve palsy
- Evidence of raised intracranial pressure (for example papilloedema, abnormal posturing)
Investigations
Blood cultures (before antibiotics if this does not delay treatment):Causative organism may be isolated; positive culture supports targeted therapy
FBC, CRP, U&E, LFT, coagulation profile, venous/arterial blood gas with lactate, glucose:Inflammatory response, organ dysfunction, coagulopathy/DIC, hyperlactataemia, and baseline glucose for CSF: serum comparison
Lumbar puncture with CSF microscopy, cell count, protein, glucose, Gram stain, culture, PCR:Typical bacterial pattern: neutrophilic pleocytosis, raised protein, low CSF glucose (or low CSF: serum glucose ratio), positive Gram stain/culture/PCR
Meningococcal/Pneumococcal PCR from blood (and CSF where available):May detect pathogen even after early antibiotic administration
CT head before LP only if clinically indicated:Used to assess contraindications to immediate LP (for example focal deficit, severely reduced consciousness, papilloedema, new seizures, cardiorespiratory instability)
CXR and infection focus imaging when indicated:May identify primary or contiguous focus (for example pneumonia, mastoiditis, sinusitis)
Management
Lifestyle Modifications
- Emergency escalation: treat as time-critical sepsis/meningitis, oxygen, IV access, fluid resuscitation, and urgent senior/critical care involvement
- Public health actions: immediate notification of suspected/confirmed cases and contact tracing
- Prevention after recovery: ensure age-appropriate MenB, MenACWY, pneumococcal, and other indicated vaccines; provide safety-net advice on recurrence red flags
Pharmacological Treatment
Immediate empiric parenteral antibiotics
- Ceftriaxone IV 80 mg/kg once daily in children (max 4 g daily), adjust to local protocol
- Alternative: Cefotaxime IV 50 mg/kg every 6 hours in children
- Neonates/young infants (under 3 months): Cefotaxime IV 50 mg/kg every 6-8 hours plus Amoxicillin IV 50 mg/kg every 6 hours (Listeria cover)
Do not delay first dose for imaging or LP in unstable patients. Tailor to cultures/PCR and local antimicrobial guidance.
Pre-hospital/first-contact treatment when meningococcal disease strongly suspected
- Benzylpenicillin IM/IV: under 1 year 300 mg stat
- Benzylpenicillin IM/IV: 1-9 years 600 mg stat
- Benzylpenicillin IM/IV: 10 years and over 1.2 g stat
Give immediately if transfer delay is expected and no history of anaphylaxis to penicillin.
Adjunctive corticosteroid
- Dexamethasone IV 0.15 mg/kg every 6 hours for 4 days (child regimen; max single dose commonly 10 mg)
Most useful when given just before or with first antibiotic, especially if pneumococcal meningitis is likely. Stop if an alternative diagnosis is confirmed and no ongoing indication.
Chemoprophylaxis for close contacts of meningococcal disease
- Ciprofloxacin oral single dose: adults 500 mg once
- Ciprofloxacin oral single dose: children 1 month to 11 years 30 mg/kg once (max 500 mg)
- Alternative regimens where needed: Rifampicin 2-day course, or Ceftriaxone IM single dose in pregnancy per UK guidance
Offer promptly to defined close contacts after public health risk assessment; does not replace vaccination when indicated.
Surgical / Interventional
- Neurosurgical management of complications when required (for example external ventricular drainage for hydrocephalus, drainage of subdural empyema/brain abscess)
- ENT surgery for persistent contiguous source control (for example mastoid or sinus disease)
Complications
- Cerebral infarction with focal neurological deficits
- Sensorineural hearing loss
- Seizures and later epilepsy risk
- Cognitive impairment and learning/behavioural difficulties
- Motor deficits, speech and visual impairment
- Hydrocephalus (especially in neonates/infants)
- Meningococcal septic shock, DIC, purpura fulminans, limb ischaemia/amputation
- Skin necrosis/scarring
- Subdural empyema, cerebral abscess, intracerebral haemorrhage
- Reduced long-term quality of life, anxiety, emotional sequelae
Prognosis
Outcome is strongly time-dependent: early antibiotics plus organ support improve survival substantially. Prognosis is worse at age extremes, with delayed presentation, shock, prolonged seizures, impaired consciousness, thrombocytopenia, and pneumococcal/Listeria/Gram-negative aetiology. In UK surveillance, meningococcal case fatality is low but non-trivial, and significant neurological or physical sequelae still occur in a meaningful minority of survivors.
Sources & References
💊BNF Drug References(2)
- Benzylpenicillin sodium[management.pharmacological]
- Fosfomycin[management.pharmacological]
✅NICE Guidelines(1)
📖Textbook References(20)
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 280)[context]
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 1465)[context]
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 965, 966)[context]
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 1793, 1794)[context]
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 1816)[context]
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 1001)[context]
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 280)[context]
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 982)[context]
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 282, 283)[context]
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 281)[context]
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 1693)[context]
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 1472)[context]
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 282)[context]
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 280)[context]
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 280, 281)[context]
- Oxford Handbook of Clinical Diagnosis (Huw Llewelyn, Hock Aun Ang, Keir Lewis etc.) (Z-Library).pdf(pp. 25)[context]
- [Oxford Medical Handbooks] Ian Wilkinson, Tim Raine, Kate Wiles, Anna Goodhart, Catriona Ha - Oxford Handbook of Clinical Medicine (2017, Oxford University Press) - libgen.li.pdf(pp. 837)[context]
- [Oxford Medical Handbooks] Ian Wilkinson, Tim Raine, Kate Wiles, Anna Goodhart, Catriona Ha - Oxford Handbook of Clinical Medicine (2017, Oxford University Press) - libgen.li.pdf(pp. 837, 838)[context]
- [Oxford Medical Handbooks] Ian Wilkinson, Tim Raine, Kate Wiles, Anna Goodhart, Catriona Ha - Oxford Handbook of Clinical Medicine (2017, Oxford University Press) - libgen.li.pdf(pp. 680, 681)[context]
- [Williams, Bailey and Love's Short Practice of Surgery] Norman Williams, Christopher Bulstrode, P Ronan O'Connell - Bailey & Love's Short Practice of Surgery 26E (2013, CRC Press) - libgen.li.pdf(pp. 747)[context]