Paeds · infectious-diseases
Meningitis and encephalitis
Also known as Bacterial meningitis · Viral meningitis · Aseptic meningitis · Herpes simplex encephalitis · Acute meningoencephalitis
Fellowship guide to paediatric meningitis and encephalitis: bacterial versus viral patterns, age-specific pathogens, the time-critical assessment of the febrile child with headache or altered consciousness, lumbar puncture and CSF interpretation, empiric antibiotic and aciclovir selection with doses, dexamethasone and steroid controversies, complications including hearing loss, and neurodevelopmental outcomes.
Checked against its sources on 3 Sept 2026
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Target exams
Red flags
- Altered mental state, drowsiness, or reduced responsiveness in a febrile child
- Neck stiffness with photophobia or headache in any child beyond infancy
- A bulging fontanelle in an infant, or a high-pitched cry and irritability
- A non-blanching petechial or purpurial rash suggesting meningococcal disease
- Focal neurological signs, new seizures, or focal status epilepticus suggesting encephalitis
- Fever with rapid clinical deterioration, shock, or signs of raised intracranial pressure
- A febrile infant under three months with non-specific signs that could harbour serious bacterial infection
Life stages
Care settings
Clinical exam formats
Board mappings
- Recognises bacterial meningitis as a time-critical emergency
- Distinguishes bacterial meningitis from viral meningitis and encephalitis
- Initiates empiric antibiotics before lumbar puncture when the child is unstable
- Justifies antibiotic choice by age, likely pathogen, and resistance patterns
- Interprets CSF indices and applies the bacterial meningitis score
- Manages raised intracranial pressure and septic shock complicating meningitis
- Empiric management of suspected meningitis in a febrile child
- Recognition of encephalitis and the role of aciclovir
- Counselling families about prognosis and hearing outcome after meningitis
- Bedside assessment of the febrile child with headache or altered consciousness
- Lumbar puncture technique, indications, and CSF interpretation
- Communication of diagnosis, steroid decision, and antibiotic duration
- Level 1: Presents with fever and the risk of serious bacterial infection
- Level 2: Investigation and initial management of suspected CNS infection
- Level 3: Management of complex, recurrent, or healthcare-associated CNS infection
- Age-specific bacterial meningitis pathogens and empiric regimens
- CSF interpretation and the bacterial meningitis score
- Herpes simplex encephalitis and the role of aciclovir
- History and examination of the febrile child with suspected meningitis
- Communication of lumbar puncture findings and management plan
- Structured assessment of a child with altered consciousness
- Empiric antibiotic selection for paediatric bacterial meningitis by age
- Interpretation of CSF cell count, glucose, protein, and Gram stain
- Indications for neuroimaging before lumbar puncture
- Recognition and resuscitation of the child with suspected meningitis
- Appropriate use and interpretation of CSF analysis
- Antibiotic stewardship and duration decisions
- Canadian Paediatric Society approach to febrile infants and meningitis
- Pneumococcal and meningococcal conjugate vaccine impact on epidemiology
- Hearing follow-up and neurodevelopmental surveillance after meningitis
Overview & Definition
Meningitis is inflammation of the meninges, the membranes lining the brain and spinal cord, and encephalitis is inflammation of the brain parenchyma itself. The two overlap as meningoencephalitis when both are involved, and the distinction drives both prognosis and treatment. In children these are time-critical diagnoses: a febrile infant or child with headache, neck stiffness, or altered consciousness must be presumed to harbour a central nervous system infection until proven otherwise. [3]
The clinician's first job is to separate bacterial meningitis from viral meningitis. Cochrane 2015: corticosteroids reduced severe hearing loss in children with H. influenzae meningitis, and reduced hearing loss and neurological sequelae in high-income countries, with a non-significant reduction in mortality overall. Sköldenberg randomised aciclovir 10 mg/kg 8-hourly for 10 days versus vidarabine (mortality 19 per cent versus 50 per cent). NICE does not routinely give aciclovir unless herpes simplex encephalitis is strongly suspected.[15][18][19]
Antibiotics start within 1 hour of the person with suspected bacterial meningitis arriving at hospital (NICE NG240). Auburtin found an interval of more than 3 hours between admission and antibiotics independently associated with death in adult ICU pneumococcal meningitis. Investigations including lumbar puncture must never delay the first dose if they would cause a clinically significant delay.[19][16]
References20ShowHide
- [1]Brouwer MC Epidemiology, diagnosis, and antimicrobial treatment of acute bacterial meningitis. Clin Microbiol Rev, 2010.PMID 20610819
- [2]van de Beek D Community-acquired bacterial meningitis. Nat Rev Dis Primers, 2016.PMID 27808261
- [3]Kim KS Acute bacterial meningitis in infants and children. Lancet Infect Dis, 2010.PMID 20129147
- [4]Nigrovic LE Clinical prediction rule for identifying children with cerebrospinal fluid pleocytosis at very low risk of bacterial meningitis. JAMA, 2007.PMID 17200475
- [5]Nigrovic LE Development and validation of a multivariable predictive model to distinguish bacterial from aseptic meningitis in children in the post-Haemophilus influenzae era. Pediatrics, 2002.PMID 12359784
- [6]Venkatesan A Case definitions, diagnostic algorithms, and priorities in encephalitis: consensus statement of the international encephalitis consortium. Clin Infect Dis, 2013.PMID 23861361
- [7]Glaser CA Beyond viruses: clinical profiles and etiologies associated with encephalitis. Clin Infect Dis, 2006.PMID 17109290
- [8]de Gans J Dexamethasone in adults with bacterial meningitis. N Engl J Med, 2002.PMID 12432041
- [9]Tunkel AR 2017 Infectious Diseases Society of America's Clinical Practice Guidelines for Healthcare-Associated Ventriculitis and Meningitis. Clin Infect Dis, 2017.PMID 28203777
- [10]Peltola H Hearing impairment in childhood bacterial meningitis is little relieved by dexamethasone or glycerol. Pediatrics, 2010.PMID 20008417
- [11]Mook-Kanamori BB Pathogenesis and pathophysiology of pneumococcal meningitis. Clin Microbiol Rev, 2011.PMID 21734248
- [12]Peltola H Improving the outcomes in children with bacterial meningitis. Curr Opin Infect Dis, 2009.PMID 19369866
- [13]van de Beek D, de Gans J, Spanjaard L, et al. Clinical features and prognostic factors in adults with bacterial meningitis. N Engl J Med, 2004.PMID 15509818
- [14]Drost EHGM, Schepers EN, Chekrouni N, et al. Outcomes of adults with community-acquired bacterial meningitis in the Netherlands: a prospective nationwide cohort study. Lancet Reg Health Eur, 2026.PMID 41323877
- [15]Brouwer MC, McIntyre P, Prasad K, van de Beek D Corticosteroids for acute bacterial meningitis. Cochrane Database Syst Rev, 2015.PMID 26362566
- [16]Auburtin M, Wolff M, Charpentier J, et al. Detrimental role of delayed antibiotic administration and penicillin-nonsusceptible strains in adult intensive care unit patients with pneumococcal meningitis. Crit Care Med, 2006.PMID 16915106
- [17]Whitley RJ, Alford CA, Hirsch MS, et al. Vidarabine versus acyclovir therapy in herpes simplex encephalitis. N Engl J Med, 1986.PMID 3001520
- [18]Sköldenberg B, Forsgren M, et al. Acyclovir versus vidarabine in herpes simplex encephalitis. Scand J Infect Dis Suppl, 1985.PMID 3912977
- [19]Paing A, Elliff-O'Shea L, Boardman L, Turner D, Glennie L Meningitis (bacterial) and meningococcal disease: recognition, diagnosis and management-summary of updated NICE guidance. BMJ, 2024.PMID 39603707
- [21]Hasbun R, Abrahams J, Jekel J, Quagliarello VJ Computed tomography of the head before lumbar puncture in adults with suspected meningitis. N Engl J Med, 2001.PMID 11742046