Pediatric Bacterial Meningitis

Quick Reference Card

Critical Time-Sensitive Actions

Red Flag

DOOR-TO-ANTIBIOTIC TIME: ≤60 MINUTES

Do NOT delay antibiotics for LP or imaging
Antibiotics remain effective for CSF culture up to 4 hours post-dose
Mortality increases 12.6% per hour of delay ¹

Emergency Recognition Triad

Feature	Classic Presentation	Caveat
Fever	High-grade (> 38.5°C)	May be absent in neonates, immunocompromised
Altered mental status	Lethargy, confusion, irritability	Most reliable predictor of bacterial etiology
Meningismus	Neck stiffness, Kernig/Brudzinski positive	Absent in less than 12 months; sensitivity only 30% in children

Age-Specific Pathogens: The Critical Three

Age Group	Primary Pathogens	Coverage Required
less than 1 month	Group B Streptococcus (40-50%), E. coli K1 (20-30%), Listeria monocytogenes (5-10%)	Ampicillin + Cefotaxime/Gentamicin + Acyclovir
1-3 months	GBS, E. coli, S. pneumoniae, H. influenzae type b, Listeria	Ampicillin + Ceftriaxone ± Vancomycin
> 3 months	S. pneumoniae (50-60%), N. meningitidis (25-30%), H. influenzae type b (less than 5% post-vaccine)	Ceftriaxone + Vancomycin

CSF Interpretation at a Glance

Parameter	Normal	Bacterial	Viral	TB/Fungal
Opening pressure	less than 20 cm H₂O	↑↑ (> 30)	Normal/↑	↑↑
WBC (cells/μL)	less than 5	> 1000 (PMN)	10-500 (lymph)	50-500 (lymph)
Protein (mg/dL)	less than 45	> 100	50-100	> 100
Glucose (mg/dL)	> 45 (> 50% serum)	less than 40 (less than 40% serum)	Normal	↓↓
Gram stain	Negative	Positive (60-90%)	Negative	AFB (20-40%)
Lactate (mmol/L)	less than 2.1	> 4.0	less than 3.5	> 4.0

Empiric Antibiotic Dosing Quick Reference

Age	Regimen	Doses
less than 1 month	Ampicillin + Cefotaxime + Acyclovir	Amp 75-100 mg/kg q6-8h; Cefo 50 mg/kg q6-8h; Acy 20 mg/kg q8h
1-3 months	Ampicillin + Ceftriaxone ± Vancomycin	Amp 75-100 mg/kg q6h; CTX 50 mg/kg q12h; Vanc 15 mg/kg q6h
> 3 months	Ceftriaxone + Vancomycin	CTX 50-100 mg/kg/day (max 4g); Vanc 60 mg/kg/day divided q6h

Definition and Overview

Core Definition

Bacterial meningitis is an acute purulent infection of the leptomeninges (pia mater and arachnoid) and subarachnoid space, representing a medical emergency with high morbidity and mortality in children. The condition is characterized by inflammation of the meninges caused by bacterial invasion, leading to cerebral edema, elevated intracranial pressure, and potential neurological sequelae ².

Clinical Significance

Bacterial meningitis remains one of the top 10 causes of infection-related death worldwide and carries significant risk of permanent neurological disability in survivors. Despite advances in vaccination and antimicrobial therapy, mortality rates remain 5-15% in developed countries and up to 50% in resource-limited settings ³.

Classification System

By Etiology:

Category	Characteristics	Common Organisms
Acute Bacterial	Rapid onset (less than 24-48h), purulent CSF	S. pneumoniae, N. meningitidis, H. influenzae, GBS, E. coli
Viral (Aseptic)	Subacute, lymphocytic CSF, benign course	Enteroviruses, HSV, VZV, arboviruses
Tuberculous	Chronic (weeks), basilar predominance	Mycobacterium tuberculosis
Fungal	Chronic, immunocompromised host	Cryptococcus, Candida, Aspergillus
Parasitic	Geographic exposure, eosinophilic CSF	Angiostrongylus, Naegleria fowleri

By Age-Based Risk Stratification:

Age Category	Risk Level	Unique Considerations
Neonates (less than 28 days)	Highest	Immature immune system, vertical transmission, blood-brain barrier vulnerability
Young infants (1-3 months)	Very High	Transition period; both neonatal and community pathogens
Infants (3-12 months)	High	Post-maternal antibody decline, pre-vaccine completion
Toddlers (1-5 years)	Moderate-High	Peak incidence for pneumococcal/meningococcal disease
School-age (> 5 years)	Moderate	More classic presentation, better prognosis

Epidemiology

Global Burden

The World Health Organization estimates approximately 2.5 million cases of bacterial meningitis annually worldwide, with the highest burden in the African "meningitis belt" and in children under 5 years of age ⁴.

Incidence by Age and Pathogen

Pre-Vaccine Era vs. Post-Vaccine Era:

Pathogen	Pre-vaccine Incidence	Post-vaccine Incidence	Reduction
H. influenzae type b	40-50/100,000 less than 5 years	less than 0.5/100,000	> 99%
S. pneumoniae	15-25/100,000 less than 2 years	5-8/100,000	60-75%
N. meningitidis	1-3/100,000	0.3-0.5/100,000	70-85%
Group B Streptococcus	0.5-1.0/1,000 neonates	0.2-0.4/1,000	50-70%

Risk Factors

Host Factors:

Factor	Relative Risk	Mechanism
Age less than 2 years	10-20×	Immature immune response, incomplete vaccination
Complement deficiency (C5-C9)	5,000-10,000×	Impaired bactericidal activity against Neisseria
Asplenia (functional/anatomic)	50-100×	Impaired opsonization of encapsulated organisms
HIV infection	5-10×	Cell-mediated immune deficiency
CSF leak/skull fracture	100-200×	Direct bacterial access to CNS
Cochlear implants	30×	Biofilm formation, direct route
Recent neurosurgery	50×	Blood-brain barrier disruption

Environmental Factors:

Factor	Association	Notes
Crowded living conditions	2-4× risk	Day care, military barracks
Exposure to tobacco smoke	2-3× risk	Impaired mucociliary clearance
Winter/spring months	Seasonal peak	Viral co-infection, indoor crowding
Endemic areas	Variable	Meningitis belt (Sub-Saharan Africa)

Mortality and Morbidity Outcomes

Mortality by Pathogen (Treated Cases):

Organism	Mortality Rate	Highest Risk Period
S. pneumoniae	15-25%	First 48 hours
N. meningitidis	5-10%	First 24 hours
H. influenzae type b	3-6%	First 72 hours
Group B Streptococcus	10-15%	Neonatal period
E. coli K1	15-30%	Neonatal period
Listeria monocytogenes	20-30%	Extremes of age

Long-term Sequelae (Survivors):

Sequelae	Incidence	Risk Factors
Sensorineural hearing loss	10-30%	Pneumococcal etiology, delayed treatment
Cognitive impairment	10-20%	Young age, coma at presentation
Motor deficits	5-10%	Vascular complications
Seizure disorder	5-10%	Seizures during acute illness
Hydrocephalus	3-5%	Gram-negative organisms, delayed treatment
Behavioral problems	15-25%	Prolonged illness

Pathophysiology

Mechanisms of CNS Invasion

The pathogenesis of bacterial meningitis involves a complex cascade of events that can be conceptualized in distinct phases:

Phase 1: Colonization and Mucosal Invasion

Nasopharyngeal colonization (pneumococcus, meningococcus) or vertical transmission (GBS, E. coli)
Bacterial adherence via pili, adhesins, and capsular polysaccharides
Mucosal invasion through paracellular and transcellular routes

Phase 2: Bloodstream Survival and Invasion

Encapsulated organisms resist complement-mediated killing
High-grade bacteremia (> 10³ CFU/mL) increases CNS invasion risk
Survival in bloodstream: 4-8 hours before CNS seeding

Phase 3: Blood-Brain Barrier Penetration

Mechanism	Organisms	Target
Transcellular (receptor-mediated)	S. pneumoniae, GBS	Brain microvascular endothelium
Paracellular (tight junction disruption)	E. coli K1, N. meningitidis	Endothelial junctions
Choroid plexus invasion	Listeria, E. coli	Choroid epithelium
Trojan horse (monocyte carriage)	Listeria	Infected macrophages

Phase 4: Subarachnoid Space Inflammation

The CSF is an "immunologically privileged" compartment with:

Low complement levels
Minimal immunoglobulin
Absent resident phagocytes
Limited opsonization capacity

This allows rapid bacterial proliferation and triggers intense inflammatory response.

Inflammatory Cascade

Diagram Placeholder

Key Inflammatory Mediators:

Mediator	Source	Effect	Peak Level
TNF-α	Microglia, macrophages	BBB permeability, apoptosis	2-6 hours
IL-1β	Microglia, astrocytes	Fever, inflammation	4-8 hours
IL-6	Endothelium, leukocytes	Acute phase response	6-12 hours
IL-8	Endothelium	Neutrophil chemotaxis	4-12 hours
Matrix metalloproteinases	Neutrophils	BBB degradation	12-24 hours
Nitric oxide	iNOS in macrophages	Vasodilation, oxidative damage	6-24 hours

Cerebral Complications

Intracranial Pressure Dynamics:

Vasogenic edema: BBB breakdown → plasma protein extravasation
Cytotoxic edema: Neuronal/glial cell swelling from energy failure
Interstitial edema: Impaired CSF absorption
Increased CSF production: Choroid plexus inflammation

Cerebrovascular Complications:

Complication	Mechanism	Incidence
Vasculitis	Inflammation of meningeal vessels	15-25%
Arterial infarction	Thrombosis, spasm	5-15%
Venous thrombosis	Sagittal sinus, cortical veins	3-5%
Subdural effusion	BBB dysfunction, inflammation	10-30%
Subdural empyema	Secondary infection of effusion	1-2%

Pathogen-Specific Virulence Factors

Organism	Key Virulence Factors	Clinical Implications
S. pneumoniae	Polysaccharide capsule, pneumolysin, autolysin	High mortality, hearing loss risk
N. meningitidis	LOS endotoxin, capsule, pili, Opa/Opc proteins	DIC, purpura fulminans, adrenal hemorrhage
H. influenzae type b	PRP capsule, IgA protease	Subdural effusions common
GBS	Capsular sialic acid, β-hemolysin	Neonatal focus, high relapse rate
E. coli K1	K1 capsule (sialic acid), FimH adhesin	Neonatal meningitis, poor prognosis
Listeria	Listeriolysin O, ActA (intracellular spread)	Rhombencephalitis, immunocompromised

Clinical Presentation

Age-Specific Presentations

Neonates (less than 28 Days)

Red Flag

Neonatal Meningitis: The Great Mimicker Classic meningeal signs are absent in > 90% of neonates. Maintain high index of suspicion in any unwell neonate.

Clinical Features:

System	Early Signs	Late Signs
General	Temperature instability (hypo- or hyperthermia), poor feeding	Lethargy, weak cry, apnea
Neurological	Irritability, high-pitched cry	Bulging fontanelle, seizures, opisthotonus
Respiratory	Tachypnea, respiratory distress	Apnea, cyanosis
Cardiovascular	Tachycardia	Poor perfusion, hypotension
Gastrointestinal	Feeding intolerance, vomiting	Abdominal distension, ileus

Early-Onset vs. Late-Onset Neonatal Meningitis:

Feature	Early-Onset (less than 7 days)	Late-Onset (7-90 days)
Transmission	Vertical (maternal)	Horizontal (nosocomial/community)
Primary organisms	GBS, E. coli, Listeria	GBS, E. coli, S. aureus, CoNS
Associated features	Maternal risk factors (PROM, GBS+, fever)	Often no maternal factors
Mortality	20-30%	10-15%

Infants (1-12 Months)

Clinical Features:

Feature	Prevalence	Notes
Fever	90-95%	May be only sign
Irritability	80-90%	Inconsolable, paradoxical
Poor feeding/vomiting	60-70%	Non-specific
Lethargy	50-60%	Concerning sign
Bulging fontanelle	25-35%	Specific but late sign
Seizures	20-30%	Often focal
Neck stiffness	15-25%	Unreliable under 12 months

"Paradoxical Irritability": Infant cries more when held/comforted (due to meningeal irritation with movement)

Children (> 12 Months)

Classic Triad Prevalence:

Sign	Children 1-5 years	Children > 5 years
Fever	85-95%	90-95%
Headache	40-60%	80-90%
Neck stiffness	40-60%	70-85%
All three	20-30%	40-50%

Additional Features:

Feature	Prevalence	Significance
Photophobia	30-50%	Meningeal irritation
Nausea/vomiting	60-80%	Raised ICP, direct irritation
Altered mental status	30-50%	Poor prognostic sign
Seizures	15-25%	Early: poor prognosis; Late: may indicate complication
Petechial/purpuric rash	10-20% (50-80% in meningococcal)	Medical emergency
Focal deficits	10-15%	Vascular complication, abscess

Physical Examination Signs

Meningeal Signs

Kernig's Sign:

Patient supine with hip flexed to 90°
Attempt to extend knee
Positive: Pain/resistance at > 135° flexion prevented
Sensitivity: 5-10% (children); Specificity: 95%

Brudzinski's Sign:

Patient supine
Passive neck flexion
Positive: Involuntary hip/knee flexion
Sensitivity: 5-10% (children); Specificity: 95%

Nuchal Rigidity:

Resistance to passive neck flexion
Most reliable in children > 2 years
Sensitivity: 30-70%; Specificity: 70-95%

Jolt Accentuation:

Patient turns head horizontally 2-3×/second
Positive: Worsening headache
Sensitivity: 97%; Specificity: 60% (adults)

Assessment of Raised Intracranial Pressure

Sign	Finding	Implication
Fontanelle (infants)	Bulging, tense, non-pulsatile	↑ICP, needs urgent intervention
Consciousness	GCS decline, Cushing response	Impending herniation
Pupils	Unilateral dilation, sluggish	Uncal herniation
Posturing	Decorticate/decerebrate	Severe ↑ICP
Papilledema	Blurred disc margins, venous engorgement	Chronic ↑ICP (develops over hours-days)
VI nerve palsy	Lateral gaze limitation	False localizing sign of ↑ICP

Meningococcal Disease: Special Considerations

Red Flag

MENINGOCOCCEMIA: TIME-CRITICAL EMERGENCY

Median time from first symptom to death: 24 hours
Petechiae can evolve to purpura fulminans within 2-4 hours
Administer antibiotics IMMEDIATELY (do not wait for IV access - give IM)

Evolution of Meningococcal Rash:

Stage	Time	Appearance	Distribution
1. Macular	0-4 hours	Blanching pink macules	Non-specific
2. Petechial	4-8 hours	Non-blanching less than 2mm lesions	Trunk, extremities, conjunctivae
3. Purpuric	8-12 hours	Larger non-blanching lesions	Spreading, coalescing
4. Purpura fulminans	12-24 hours	Extensive hemorrhagic necrosis	Diffuse, with DIC

Glass Test (Tumbler Test):

Press clear glass firmly against rash
Non-blanching = concerning for meningococcemia
Sensitivity 50-60% in early disease; higher specificity

Red Flags and Contraindications

Absolute Contraindications to Immediate LP

Red Flag

DO NOT PERFORM LP IF:

Signs of cerebral herniation:
- Abnormal posturing (decerebrate/decorticate)
- Unequal, dilated, or unreactive pupils
- Abnormal oculocephalic reflexes
- Cushing triad (bradycardia, hypertension, irregular respiration)
Cardiovascular instability:
- Shock requiring active resuscitation
- Respiratory failure
Local contraindications:
- Skin infection over LP site
- Suspected spinal epidural abscess
Coagulopathy:
- Platelets less than 50,000/μL
- INR > 1.5
- Active DIC (start antibiotics first)

ALWAYS START ANTIBIOTICS BEFORE CT/LP IF MENINGITIS SUSPECTED

Indications for CT Before LP

The IDSA recommends CT before LP in patients with ⁵:

Clinical Feature	Rationale
Immunocompromised state	Higher risk of space-occupying lesion
History of CNS disease	Mass lesion, shunt malfunction
New-onset seizures	Focal lesion risk
Papilledema	Established raised ICP
Focal neurological deficit	Space-occupying lesion
Altered consciousness (GCS ≤12)	Higher herniation risk

Important Caveat: A normal CT does NOT exclude raised ICP. Up to 5% of patients with normal CT may still herniate post-LP ⁶.

Life-Threatening Presentations Requiring Immediate Intervention

Presentation	Immediate Action	Timeframe
Purpuric rash + fever	IV/IM antibiotics, aggressive fluid resuscitation	less than 5 minutes
Signs of herniation	Head elevation, hyperventilation (short-term), osmotherapy, neurosurgery consult	less than 10 minutes
Status epilepticus	Benzodiazepines, airway protection, antibiotics	less than 5 minutes
Septic shock	IV fluids (20 mL/kg bolus), vasopressors, antibiotics	less than 15 minutes
Respiratory failure	Intubation, mechanical ventilation, antibiotics	less than 10 minutes

Differential Diagnosis

Primary Differential Considerations

Diagnosis	Key Distinguishing Features	Investigations
Viral meningitis	Less toxic, lymphocytic CSF, normal glucose	CSF viral PCR (enterovirus, HSV)
Viral encephalitis	Altered mentation > meningismus, behavioral changes, seizures	CSF HSV PCR, MRI (temporal lobe changes)
Brain abscess	Focal deficits, headache, fever; may lack meningismus	CT/MRI with contrast
Subarachnoid hemorrhage	Thunderclap headache, sudden onset, xanthochromia	CT head, LP (xanthochromia)
Tuberculous meningitis	Subacute onset (weeks), cranial nerve palsies, basilar enhancement	CSF AFB, adenosine deaminase, PCR
Partially treated bacterial meningitis	Prior antibiotics, atypical CSF	Clinical history, PCR
Drug-induced aseptic meningitis	NSAID, IVIG, or antibiotic exposure	Temporal relationship to drug
Autoimmune meningitis	Recurrent episodes, systemic autoimmune features	Autoantibodies, biopsy

Mimics in Specific Populations

Neonates:

Condition	Features	Differentiation
Neonatal sepsis without meningitis	Similar presentation	LP negative
Inborn errors of metabolism	Poor feeding, lethargy, seizures	Metabolic workup, no fever
Non-accidental injury	Altered consciousness, bulging fontanelle	Retinal hemorrhages, imaging
Intracranial hemorrhage	Bulging fontanelle, seizures	CT/MRI, coagulation studies

Infants and Children:

Condition	Features	Differentiation
Complex febrile seizure	Postictal drowsiness, fever	LP often performed; CSF normal
Acute viral gastroenteritis with dehydration	Lethargy, fever	Hydration improves mental status
Sinusitis with extension	Headache, fever, focal signs	CT sinuses, MRI brain
Kawasaki disease	Irritability, fever	Other diagnostic criteria, CSF pleocytosis

Diagnostic Approach

Clinical Decision Rules

Bacterial Meningitis Score (BMS)

The Bacterial Meningitis Score was developed and validated by Nigrovic et al. ⁷ to identify children with CSF pleocytosis at very low risk of bacterial meningitis:

Criteria (all must be absent for low risk):

Criterion	Points	Definition
Positive CSF Gram stain	1	Any organisms seen
CSF ANC ≥1,000 cells/μL	1	Absolute neutrophil count
CSF protein ≥80 mg/dL	1	Elevated protein
Peripheral blood ANC ≥10,000/μL	1	Systemic inflammation
Seizure at or prior to presentation	1	Any seizure activity

Interpretation:

Score 0: Very low risk of bacterial meningitis (less than 0.1%)
Score ≥1: Cannot rule out bacterial meningitis

Validation: Sensitivity 99.3%, Negative predictive value 99.9% ⁷

Limitations:

Not validated in infants less than 29 days
Not for use in immunocompromised patients
Not for patients with prior antibiotics

UK-ChiMES Clinical Decision Models (2024)

A prospective multicenter UK study (Martin et al., 2024) ⁸ involving 3,002 children with suspected meningitis/encephalitis developed two novel clinical decision rules:

Pre-LP Model (before lumbar puncture):

Sensitivity: 82%
Specificity: 71%
Used to assess bacterial meningitis risk before LP

Post-LP Model (after CSF results):

Sensitivity: 84%
Specificity: 93%
Incorporates CSF parameters for definitive risk stratification

Key Findings:

Bacterial meningitis comprised only 6% (180/3,002) of suspected cases
Enterovirus most common in less than 6 months and 10-16 years
N. meningitidis/S. pneumoniae most common at 6 months-9 years
Bacterial Meningitis Score had NPV of 95.3% in this cohort

These models provide evidence-based tools to improve diagnostic accuracy and reduce unnecessary antibiotic use ⁸.

Lumbar Puncture

Technique and Safety

Positioning Options:

Position	Advantages	Disadvantages
Lateral decubitus	More accurate opening pressure	May be difficult in obese/young infants
Sitting	Easier landmark identification	Cannot measure opening pressure

Needle Selection:

Age	Needle Gauge	Length
Neonate	22G	1.5 inch (3.8 cm)
Infant	22G	1.5 inch (3.8 cm)
Child	22G	2.5-3.5 inch (6.4-8.9 cm)
Adolescent	20-22G	3.5 inch (8.9 cm)

Required CSF Volume:

Test	Minimum Volume
Cell count + differential	0.5-1 mL
Gram stain + culture	1-2 mL
Glucose + protein	0.5 mL
PCR panel	0.2-0.5 mL
Total recommended	3-4 mL

CSF Interpretation

Normal CSF Values by Age:

Parameter	Preterm	Term Neonate	1-3 months	> 3 months
WBC (cells/μL)	less than 25	less than 22	less than 15	less than 5
% PMN	less than 60%	less than 60%	less than 5%	less than 5%
Protein (mg/dL)	less than 150	less than 100	less than 80	less than 45
Glucose (mg/dL)	34-119	34-119	40-80	45-80
CSF:serum glucose	> 50%	> 50%	> 50%	> 60%

CSF Findings in Bacterial vs. Viral Meningitis:

Parameter	Bacterial	Viral	Sensitivity	Specificity
WBC > 1000/μL	Common	Rare	80%	85%
PMN > 80%	Common	Early viral	75%	80%
Glucose less than 40 mg/dL	Common	Rare	80%	95%
CSF:serum glucose less than 0.4	Common	Rare	80%	95%
Protein > 100 mg/dL	Common	Occasional	70%	75%
Lactate > 4 mmol/L	Common	Rare	90%	90%
Positive Gram stain	60-90%	Negative	60-90%	99%

Traumatic LP Interpretation

Correction Formulas:

WBC correction for bloody tap:
- Predicted WBC = Observed WBC - (WBC_blood × RBC_CSF / RBC_blood)
- Alternative: Subtract 1 WBC per 500-1000 RBCs
Protein correction:
- Subtract 1 mg/dL protein per 1000 RBCs

When to Repeat LP:

Traumatic tap with clinical suspicion
Unable to interpret results
Not indicated routinely after 48-72 hours of treatment

Laboratory Investigations

Essential Blood Tests

Test	Purpose	Expected Findings
CBC with differential	Assess WBC, platelet count	Leukocytosis (often left shift), thrombocytopenia in severe disease
Blood cultures (×2)	Identify pathogen	Positive in 50-80% of bacterial meningitis
CRP	Inflammatory marker	Elevated; helps distinguish bacterial from viral
Procalcitonin	Bacterial infection marker	≥0.5 ng/mL suggests bacterial; \u003e 2 ng/mL highly specific ⁹
Procalcitonin (prognostic)	Severity/outcome biomarker	Cutoff 19.6 ng/mL (admission) predicts short-term complications; 62.4 ng/mL (24h) predicts mortality ¹⁰
Serum glucose	Calculate CSF:serum ratio	Obtain before/with LP
Coagulation studies	Pre-LP assessment	PT/INR, aPTT, platelets if concerns
BMP/electrolytes	Assess for SIADH, shock	Hyponatremia common (SIADH in 25-50%)
Lactate	Sepsis severity	Elevated in septic shock

CSF Studies

Routine:

Test	Tube	Priority
Cell count + differential	1 and 4	Essential
Gram stain and culture	2	Essential
Protein	3	Essential
Glucose	3	Essential

Additional/Specialized:

Test	Indication	Sensitivity/Specificity
CSF multiplex PCR	All suspected bacterial meningitis	90-95% / 99% for covered organisms ¹¹
HSV PCR	Neonates, encephalitis features	98% / 99%
Enterovirus PCR	Suspected viral meningitis	95% / 99%
CSF lactate	Differentiate bacterial vs. viral	90% / 90% (cutoff > 4 mmol/L)
Latex agglutination	Rapid antigen detection	Variable; largely replaced by PCR
CSF procalcitonin	Bacterial vs. viral	90% / 85%

Imaging

Indications for Neuroimaging

CT Head (Non-contrast first, then contrast):

Indication	Rationale
Signs of raised ICP or herniation	Rule out mass effect before LP
Focal neurological signs	Mass lesion, abscess, infarct
Prolonged or new seizures	Focal lesion, complications
Immunocompromised host	Opportunistic infections, masses
Deteriorating clinical course	Complications (hydrocephalus, abscess, infarct)
Persistent fever > 48-72h on antibiotics	Secondary complications
Suspected mastoiditis/sinusitis extension	Source identification

MRI Brain (With gadolinium):

Indication	Findings
Suspected encephalitis	Temporal lobe involvement (HSV)
Subdural empyema	Rim-enhancing collection
Vascular complications	DWI for acute infarct
Venous sinus thrombosis	MRV abnormalities
Basilar meningitis	Meningeal enhancement, hydrocephalus
Poor response to therapy	Evaluate for secondary complications

Treatment

Emergency Management Algorithm

Diagram Placeholder

Antimicrobial Therapy

Empiric Treatment by Age

Neonates (less than 1 month):

Drug	Dose	Interval	Coverage
Ampicillin	75-100 mg/kg/dose	q6-8h (age-dependent)	GBS, Listeria, Enterococcus
Cefotaxime	50 mg/kg/dose	q6-8h	E. coli, GNR, GBS
OR Gentamicin	4-5 mg/kg/dose	q24-48h (if cefotaxime unavailable)	GNR synergy
Acyclovir	20 mg/kg/dose	q8h	HSV (always add in neonates)

Dosing by Postnatal and Gestational Age:

Postmenstrual Age	Ampicillin	Cefotaxime	Gentamicin
≤29 weeks PMA	q12h (0-28d), q8h (> 28d)	q12h (0-28d), q8h (> 28d)	q48h
30-36 weeks PMA	q12h (0-14d), q8h (> 14d)	q12h (0-14d), q8h (> 14d)	q36h
37-44 weeks PMA	q8h (0-7d), q6h (> 7d)	q8h (0-7d), q6h (> 7d)	q24h
≥45 weeks PMA	q6h	q6h	q24h

Infants 1-3 months:

Drug	Dose	Interval	Coverage
Ampicillin	75-100 mg/kg/dose	q6h	Listeria, Enterococcus
Ceftriaxone	50 mg/kg/dose	q12h or 100 mg/kg q24h	Pneumococcus, H. flu, GNR, Meningococcus
± Vancomycin	15 mg/kg/dose	q6h	Resistant pneumococcus
± Acyclovir	20 mg/kg/dose	q8h	If HSV concern

Children > 3 months:

Drug	Dose	Interval	Maximum	Coverage
Ceftriaxone	50-100 mg/kg/day	q12-24h	4 g/day	S. pneumoniae, N. meningitidis, H. flu
Vancomycin	60 mg/kg/day	q6h	2 g/dose	Resistant S. pneumoniae (MIC > 1 μg/mL)

Pathogen-Directed Therapy

Once Organism Identified:

Organism	First-Line	Alternative	Duration
S. pneumoniae (PCN-S, MIC less than 0.1)	Penicillin G OR Ampicillin	Ceftriaxone	10-14 days
S. pneumoniae (PCN-I, MIC 0.1-1)	Ceftriaxone	Cefotaxime	10-14 days
S. pneumoniae (PCN-R, MIC > 1)	Ceftriaxone + Vancomycin	Add rifampin	10-14 days
N. meningitidis	Penicillin G OR Ceftriaxone	Chloramphenicol	7 days
H. influenzae (β-lactamase neg)	Ampicillin	Ceftriaxone	7-10 days
H. influenzae (β-lactamase pos)	Ceftriaxone	Cefotaxime	7-10 days
Group B Streptococcus	Penicillin G ± Gentamicin	Ampicillin	14-21 days
E. coli	Ceftriaxone OR Cefotaxime	Meropenem (ESBL)	21 days
Listeria monocytogenes	Ampicillin ± Gentamicin	TMP-SMX	21 days

Adjunctive Dexamethasone

Rationale: Dexamethasone reduces the inflammatory response to bacterial lysis induced by antibiotics, thereby decreasing meningeal inflammation, cerebral edema, and neurological sequelae ¹².

Evidence: The Cochrane meta-analysis (2015) demonstrated that dexamethasone:

Reduces hearing loss (RR 0.67; 95% CI 0.51-0.88)
Reduces neurological sequelae in high-income countries
Most beneficial for H. influenzae meningitis
Probable benefit for pneumococcal meningitis in children ¹²

Dosing Protocol:

Parameter	Recommendation
Dose	0.15 mg/kg/dose IV
Frequency	Every 6 hours
Duration	4 days (some protocols: 2 days)
Timing	Before or with first antibiotic dose (ideally 15-20 min before)

When to Use:

Population	Recommendation	Evidence Level
Children > 6 weeks with bacterial meningitis	Recommended	Strong
Hib meningitis	Strongly recommended	High quality
Pneumococcal meningitis	Recommended	Moderate quality
Neonates	NOT recommended	Insufficient evidence
Already received antibiotics	Consider if less than 4 hours since first dose	Weak

When to Discontinue:

Confirmed viral meningitis
Gram stain and culture negative after 48-72 hours in well child
TB meningitis (use separate steroid protocol)

Supportive Care

Fluid Management

Red Flag

SIADH Management:

SIADH occurs in 25-50% of bacterial meningitis
Monitor serum sodium q6-12h initially
Avoid hypotonic fluids
Fluid restriction only if symptomatic hyponatremia

Clinical State	Fluid Strategy
Euvolemic, stable	Isotonic maintenance (D5NS or D5LR)
Suspected SIADH	Isotonic fluids, consider 75% maintenance if Na less than 130
Septic shock	Aggressive resuscitation (20 mL/kg boluses, repeat PRN)
Raised ICP	Avoid hyponatremia, consider hypertonic saline

Seizure Management

Medication	Dose	Notes
Lorazepam	0.1 mg/kg IV (max 4 mg)	First-line for acute seizure
Midazolam	0.2 mg/kg IM/IN	If no IV access
Levetiracetam	40-60 mg/kg IV (max 3g)	Second-line, maintenance
Phenobarbital	20 mg/kg IV	Neonates, refractory seizures
Phenytoin/Fosphenytoin	20 mg PE/kg IV	Alternative second-line

Prophylactic Anticonvulsants: Not routinely recommended unless seizures occur

Management of Raised ICP

Intervention	Mechanism	Notes
Head elevation 30°	Improve venous drainage	First-line, non-invasive
Avoid hyperventilation	Short-term PCO₂ reduction	Only brief temporizing measure
Hypertonic saline (3%)	Osmotic effect	3-5 mL/kg bolus, maintain Na 145-155
Mannitol	Osmotic diuresis	0.5-1 g/kg; monitor osmolar gap
Neurosurgical consultation	EVD if refractory	For hydrocephalus, refractory ICP

Pain Management

Medication	Dose	Notes
Paracetamol	15 mg/kg q4-6h (max 75 mg/kg/day)	First-line antipyretic/analgesic
Ibuprofen	10 mg/kg q6-8h	Avoid if dehydrated or renal impairment
Morphine	0.05-0.1 mg/kg IV q2-4h	For severe pain; monitor respirations

Duration of Therapy

Organism	Duration	Notes
N. meningitidis	5-7 days	Shortest duration ¹³
H. influenzae	7-10 days	Standard; recent meta-analysis supports shorter courses ¹³
S. pneumoniae	7-14 days	Shorter courses (7 days) non-inferior in uncomplicated cases ¹³
Group B Streptococcus	14-21 days	Risk of relapse with shorter courses
Listeria monocytogenes	21 days	High relapse risk
Gram-negative bacilli	21 days or longer	Poor CSF penetration
Unknown organism	10-14 days	Based on clinical response

Recent Evidence on Duration:

A 2023 systematic review and meta-analysis by Sudo et al. ¹³ evaluated 6 RCTs (1,333 children) comparing shorter (≤7 days) versus longer (10-14 days) antibiotic courses for bacterial meningitis. Key findings:

No significant differences in treatment failure, relapse, mortality, or neurological complications
Shorter therapy supported for uncomplicated meningitis due to S. pneumoniae, H. influenzae, and N. meningitidis
Important for antimicrobial stewardship and reducing adverse effects
Caution advised for complicated cases or infections by other pathogens

Complications

Acute Complications

Syndrome of Inappropriate ADH Secretion (SIADH)

Feature	Details
Incidence	25-50% of bacterial meningitis
Mechanism	Hypothalamic-pituitary dysfunction, meningeal inflammation
Diagnosis	Hyponatremia + euvolemia + urine osm > 100 + urine Na > 40
Management	Fluid restriction (unless shocked), isotonic fluids
Resolution	Usually within 48-72 hours

Cerebral Edema and Raised ICP

Feature	Details
Incidence	10-30%
Risk factors	Young age, delayed treatment, pneumococcal etiology
Monitoring	Clinical signs, ICP monitoring in severe cases
Complications	Herniation, brainstem compression

Subdural Collections

Type	Incidence	Management
Subdural effusion (sterile)	10-30% (especially Hib)	Observation if asymptomatic
Subdural empyema	1-2%	Neurosurgical drainage + antibiotics

Indications for drainage:

Mass effect with midline shift
Increasing head circumference
Persistent fever despite antibiotics
Neurological deterioration

Vascular Complications

Complication	Incidence	Mechanism
Arterial infarction	5-15%	Vasculitis, thrombosis
Venous thrombosis	3-5%	Dehydration, hypercoagulability
Hemorrhage	1-3%	DIC, vascular injury

Seizures

Timing	Significance	Management
Early (≤72h)	Common (20-30%), not always prognostic	Acute treatment
Late (> 72h)	May indicate complication	Imaging, evaluate for abscess/infarct
Status epilepticus	Medical emergency	Aggressive treatment, ICU

Long-term Sequelae

Hearing Loss

The most common long-term complication of bacterial meningitis in children.

Pathogen	Incidence	Mechanism
S. pneumoniae	20-35%	Labyrinthitis, cochlear damage
H. influenzae	10-15%	Labyrinthitis
N. meningitidis	5-10%	Less common
GBS (neonatal)	10-20%	Cochlear damage

Screening Protocol:

All survivors: Audiology evaluation before hospital discharge
Repeat at 1 month and 6 months
Annual follow-up if abnormal
Cochlear implant evaluation for severe bilateral loss

Role of Dexamethasone: Reduces hearing loss, particularly in Hib meningitis (NNT = 10-15) ¹²

Neurological Sequelae

Sequela	Incidence	Risk Factors
Cognitive impairment	10-20%	Young age, coma, seizures during illness
Motor deficits (hemiparesis, quadriparesis)	5-10%	Vascular complications
Epilepsy	5-10%	Seizures during acute illness, cortical damage
Behavioral/attention problems	15-25%	School-age at diagnosis
Hydrocephalus (requiring shunt)	3-5%	Gram-negative, delayed treatment

Neonatal-Specific Predictors of Poor Outcome

A 2024 systematic review by Liu et al. ¹⁴ analyzed 20 studies (neonates less than 90 days) and identified key prognostic factors:

Most Consistently Associated with Poor Outcome (by multivariate analysis):

Preterm birth/low birth weight: 2.14-26.27-fold increased risk of death (risk increases with degree of prematurity)
Coma: 11.14-31.85-fold increased risk of death
Elevated CSF protein: Variable cutoffs (1.88-5.0 g/L); associated with poor outcomes
Seizures: Especially persistent seizures \u003e72h; associated with moderate/severe disability

Pathogen-Specific Outcomes:

GBS: Mortality 7-14%; moderate/severe disability in 34% of survivors
E. coli/Gram-negative: Higher mortality (28.6% vs 10.7%); higher sequelae rate (58% vs 35% for GBS)
S. pneumoniae: Associated with serious CNS complications (OR 4.83) and death (OR 4.62)

Neuroimaging Predictors:

Abnormal cerebral ultrasound: Associated with adverse motor outcome (OR 5.3)
Extensive MRI lesions: Predict adverse cognitive (OR 7.0) and motor outcomes (OR 10.7-12.6)

Neurodevelopmental Follow-up

Recommended Surveillance Schedule:

Age at Meningitis	Follow-up	Assessments
Neonatal	q3 months × 2 years, then annually	Developmental milestones, hearing, vision
Infant/Toddler	q6 months × 2 years, then annually	Developmental, hearing, behavior
School-age	Annually × 5 years	Academic performance, hearing, psychosocial

Prevention

Vaccination

Conjugate Vaccines

Vaccine	Target	Schedule (US/UK)	Effectiveness
Hib conjugate	H. influenzae type b	2, 4, 6 months + booster	> 99% reduction
PCV13/PCV15/PCV20	13/15/20 pneumococcal serotypes	2, 4, 6 months + booster	80-90% against vaccine serotypes
MenACWY	N. meningitidis A, C, W, Y	11-12 years + booster	85-100%
MenB	N. meningitidis serogroup B	10+ years (varies by country)	80-95%

Catch-up and High-Risk Schedules

Risk Group	Additional Vaccination
Asplenia (functional/anatomic)	Complete all meningococcal vaccines, PCV, Hib
Complement deficiency	MenACWY + MenB, boosters q5 years
HIV infection	Additional PCV doses
Cochlear implant recipients	Additional PCV doses
Travel to endemic areas	MenACWY before travel

Chemoprophylaxis

Meningococcal Disease Contacts

Red Flag

Close contacts of meningococcal disease require prophylaxis within 24 hours of case identification

Definition of Close Contact:

Household members
Day care/school contacts (close proximity)
Anyone with direct exposure to oral secretions (kissing, sharing utensils)
Healthcare workers with unprotected exposure to respiratory secretions
Airplane passengers sitting directly next to case for > 8 hours

Prophylaxis Regimens:

Agent	Dose	Duration	Notes
Rifampin	10 mg/kg q12h (max 600 mg)	2 days	First-line for children
Ceftriaxone	125 mg IM (≤15 years); 250 mg IM (> 15 years)	Single dose	Preferred for pregnancy
Ciprofloxacin	20 mg/kg (max 500 mg) PO	Single dose	> 1 month age
Azithromycin	10 mg/kg (max 500 mg) PO	Single dose	Alternative

Hib Disease Contacts

Indications for Prophylaxis:

Household with at least one contact less than 4 years who is unimmunized/under-immunized
Household with immunocompromised individual
Day care/nursery with two or more cases within 60 days

Regimen:

Rifampin 20 mg/kg/day (max 600 mg) PO once daily × 4 days

Intrapartum Prophylaxis for GBS

Risk Factor	Indication for IAP
Previous infant with invasive GBS disease	Always
GBS bacteriuria during current pregnancy	Always
Positive GBS screening (35-37 weeks)	Always
Unknown GBS status + any of:	Consider
- Delivery less than 37 weeks
- Rupture of membranes > 18 hours
- Intrapartum temperature ≥38°C

IAP Regimen:

Penicillin G 5 million units IV, then 2.5-3 million units q4h until delivery
Alternative: Ampicillin 2g IV, then 1g q4h

Special Populations

Neonates

Unique Considerations:

Factor	Implication
Immature blood-brain barrier	Easier pathogen entry
Deficient complement	Poor opsonization
Low immunoglobulin levels	Reduced humoral immunity
Decreased neutrophil function	Impaired bacterial killing
Non-specific presentation	Low threshold for workup

HSV Meningitis/Meningoencephalitis:

Always consider HSV in neonates with meningitis, especially:

Maternal history of genital herpes
Vesicular rash
Seizures
CSF pleocytosis with negative bacterial cultures
Hepatitis, coagulopathy

Management:

Acyclovir 20 mg/kg IV q8h empirically for all neonates with suspected meningitis
Continue for 21 days if HSV CNS disease confirmed
Repeat LP at end of treatment to confirm negative HSV PCR

Immunocompromised Children

Condition	Additional Pathogens	Modified Empiric Therapy
HIV/AIDS	Cryptococcus, TB, CMV, toxoplasmosis	Add amphotericin B, consider TB coverage
Post-transplant	Listeria, fungi, CMV	Add ampicillin, consider antifungals
Neutropenia	Pseudomonas, Aspergillus	Anti-pseudomonal coverage
Primary immunodeficiency	Cryptococcus, Mycobacteria	Individualized approach
Post-splenectomy	Encapsulated organisms	Aggressive coverage, even for "minor" fevers

VP Shunt-Associated Meningitis

Common Organisms:

Coagulase-negative staphylococci (50%)
S. aureus (25%)
Gram-negative bacilli (15-20%)
Propionibacterium acnes (5%)

Management:

Empiric: Vancomycin + Ceftazidime or Meropenem
Shunt externalization or removal often required
CSF obtained from shunt tap (by neurosurgery)
Intraventricular antibiotics may be needed

Post-Neurosurgical Meningitis

Organisms:

Gram-negative bacilli (Pseudomonas, Acinetobacter)
S. aureus, coagulase-negative staphylococci
Resistant organisms more common

Empiric Therapy:

Vancomycin + Meropenem or Cefepime
Consider intrathecal/intraventricular therapy for resistant organisms

Monitoring and Follow-up

Inpatient Monitoring

Clinical Parameters

Parameter	Frequency	Target
Vital signs	q2-4h initially	Temperature normalizing, stable hemodynamics
Neurological assessment	q4-6h	GCS improving, no new deficits
Head circumference (infants)	Daily	No rapid increase
Fluid balance	q8-12h	Adequate output, no overload

Laboratory Monitoring

Test	Frequency	Purpose
Serum sodium	q6-12h initially, then daily	SIADH detection
CRP	Day 0, 2, and before discharge	Response to treatment
Blood cultures	Day 0; repeat if febrile > 48h on antibiotics	Clearance confirmation
CSF (repeat LP)	Not routine; see indications below

Indications for Repeat LP:

Indication	Timing
Poor clinical response at 48-72 hours	As needed
GNR meningitis (to confirm sterilization)	48-72 hours
Persistent fever	Case-by-case
Neonatal meningitis	Consider at end of treatment
Concern for secondary complication	As indicated

Discharge Criteria

Criterion	Requirement
Clinical stability	Afebrile ≥24-48h, improving mental status
Oral intake	Tolerating oral fluids/feeds
Antibiotics	Completion plan established (may include outpatient IV)
Hearing evaluation	Audiology assessment completed or scheduled
Follow-up	Appointments arranged (pediatrics, audiology, neurology if indicated)
Parent education	Red flags reviewed, medication instructions clear

Outpatient Follow-up Schedule

Visit	Timing	Assessments
Post-discharge	1-2 weeks	Clinical recovery, medication completion
Audiology	Before discharge, repeat 1 month, 6 months	Hearing evaluation
Neurology	4-6 weeks if neurological complications	Developmental assessment
Developmental	3-6 months	Milestone review
School-age	Annually for 5 years	Academic/behavioral screening

Disposition

Admission Criteria

All suspected bacterial meningitis requires hospital admission.

ICU Admission Criteria

Indication	Rationale
Altered consciousness (GCS ≤12)	Airway protection, ICP monitoring
Hemodynamic instability/shock	Vasopressor support
Respiratory failure	Mechanical ventilation
Status epilepticus	Aggressive seizure management
Signs of raised ICP/herniation	ICP management, neurosurgery
Rapidly evolving purpura/DIC	Critical care support
Neonates with meningitis	Higher monitoring needs

General Ward Admission

Indication	Criteria
Confirmed/suspected bacterial meningitis	GCS > 12, stable hemodynamics
Viral meningitis requiring IV therapy	Significant symptoms, unable to tolerate oral

Outpatient Management

Viral meningitis may be managed as outpatient if:

Child > 1 year of age
Well-appearing, tolerating oral intake
No toxic appearance or altered consciousness
Confirmed enterovirus or other benign viral etiology
Reliable caregiver with good access to healthcare
Clear return precautions provided

Patient and Family Education

Explaining the Diagnosis

For Bacterial Meningitis:

"Your child has an infection called meningitis - this means bacteria have gotten into the fluid surrounding the brain and spinal cord. This is a very serious infection that needs strong antibiotics given through an IV. We're starting treatment right away because quick treatment gives your child the best chance of recovery and reduces the risk of complications."

For Viral Meningitis:

"Your child has viral meningitis. While this sounds scary, viral meningitis is usually much milder than bacterial meningitis. The symptoms - headache, fever, stiff neck - should improve over the next week or two. We may not need to give antibiotics since this is caused by a virus, but we'll watch closely to make sure they're recovering well."

Red Flags for Parents

Return immediately if:

Worsening headache or confusion
New seizures
Increasing drowsiness or difficulty waking
New rash that doesn't blanch with pressure
Weakness in arms or legs
Stiff neck getting worse
High fever returning after improvement
Poor feeding, vomiting everything

Long-term Outlook Counseling

Hearing:

"We will test your child's hearing before leaving the hospital and again in the coming months. Some children who have meningitis develop hearing problems, and early detection helps us provide the right support."

Development:

"Most children recover fully, but we recommend follow-up appointments to make sure your child is meeting developmental milestones. Let us know if you notice any concerns about their learning, behavior, or movement."

Infection Control Education

For Meningococcal Disease:

Close contacts need preventive antibiotics
Public health will be notified and assist with contact tracing
Isolation precautions in hospital for first 24 hours of antibiotic treatment

Quality Metrics and Documentation

Key Performance Indicators

Metric	Target	Rationale
Door-to-antibiotic time	≤60 minutes	Mortality reduction
Blood cultures before antibiotics	> 90%	Pathogen identification
Dexamethasone given with/before first antibiotic dose	> 80%	Hearing loss prevention
LP performed (if no contraindication)	> 95%	Diagnostic accuracy
Audiology referral before discharge	100%	Hearing loss detection
Follow-up appointment scheduled	100%	Continuity of care

Documentation Checklist

Element	Required Documentation
Initial assessment	Time of presentation, initial GCS, vital signs, meningeal signs
Antibiotic timing	Exact time of first antibiotic dose
Dexamethasone	Dose, timing relative to antibiotics
LP details	Time, opening pressure, complications, appearance
CSF results	Cell count, differential, protein, glucose, Gram stain
Clinical response	Daily neurological assessment, fever curve
Complications	Seizures, SIADH, new focal signs
Hearing screening	Audiology results and follow-up plan
Discharge planning	Duration of antibiotics, follow-up appointments, return precautions

Clinical Pearls

Diagnostic Pearls

"Treat first, diagnose second": Never delay antibiotics for diagnostic tests in suspected bacterial meningitis
Classic triad is unreliable in young children: Fever may be the only sign in infants; maintain high index of suspicion
LP interpretation requires serum glucose: Always send concurrent serum glucose for CSF:serum ratio
Negative Gram stain does not exclude bacterial meningitis: Sensitivity only 60-90%; prior antibiotics further reduce yield
CSF multiplex PCR is a game-changer: Rapid pathogen identification even after antibiotic administration ¹¹
Procalcitonin > 0.5 ng/mL strongly suggests bacterial infection: Helps distinguish from viral, but don't delay treatment for result ⁹

Treatment Pearls

Dexamethasone timing is crucial: Give before or with first antibiotic dose for maximum benefit; little benefit after first dose ¹²
Vancomycin is not routine in all ages: Only needed > 3 months for resistant pneumococcus coverage
Ampicillin required until 3 months: Listeria coverage essential in young infants
Never forget HSV in neonates: Acyclovir should be part of empiric therapy for all neonates with suspected meningitis
SIADH is common: Monitor sodium closely; avoid hypotonic fluids

Disposition Pearls

Hearing test before discharge is mandatory: Sensorineural hearing loss is the most common permanent sequela
Meningococcal contacts need prophylaxis within 24 hours: Public health must be notified immediately
Viral meningitis in older children can be managed outpatient: If well-appearing, tolerating oral, with reliable follow-up

VIVA/OSCE Scenarios

Scenario 1: Neonatal Meningitis

Stem: A 14-day-old male infant presents with fever (38.5°C), irritability, and poor feeding for 12 hours. He was born at term via SVD with no maternal complications. On examination, he is lethargic with a bulging fontanelle.

Key Points for Discussion:

Immediate actions: Stabilize, IV access, blood cultures, LP (if no contraindications), empiric antibiotics
Empiric therapy: Ampicillin + Cefotaxime + Acyclovir (always cover HSV in neonates)
Age-specific pathogens: GBS, E. coli K1, Listeria, HSV
Neonatal CSF norms differ from older children (higher WBC, protein acceptable)
Duration of therapy: 14-21 days for GBS, 21 days for GNR

Scenario 2: Meningococcal Septicemia

Stem: A 4-year-old previously healthy girl presents to ED with 6-hour history of fever and progressive non-blanching rash. She is drowsy with HR 160, BP 70/40, and spreading purpura.

Key Points for Discussion:

Immediate IM/IV antibiotics (ceftriaxone) - do not delay for IV access
Fluid resuscitation: 20 mL/kg boluses, prepare for vasopressors
This is meningococcemia until proven otherwise - life-threatening emergency
Contraindication to LP: hemodynamic instability
Contact prophylaxis within 24 hours
Complications: DIC, purpura fulminans, adrenal hemorrhage (Waterhouse-Friderichsen)

Scenario 3: LP Interpretation

Stem: A 2-year-old with 2 days of fever and vomiting has LP showing: WBC 850 cells/μL (85% PMN), protein 95 mg/dL, glucose 35 mg/dL (serum glucose 100 mg/dL), Gram stain showing Gram-positive diplococci.

Key Points for Discussion:

CSF findings consistent with bacterial meningitis
Likely organism: Streptococcus pneumoniae (Gram-positive diplococci)
CSF:serum glucose ratio = 0.35 (less than 0.4 suggests bacterial)
Treatment: Ceftriaxone + Vancomycin (until sensitivities known) + Dexamethasone
Hearing screening essential (highest risk with pneumococcal disease)

Scenario 4: Fever Without Source in Infant

Stem: A 6-week-old infant presents with fever (38.2°C) for 4 hours. Mother reports no other symptoms. Baby is feeding well. On examination, the infant appears well but has no focus of infection.

Key Points for Discussion:

"Well-appearing" doesn't exclude serious bacterial infection in young infants
Rochester/Philadelphia/Boston criteria for low-risk fever without source
Full sepsis workup indicated in this age group (blood culture, urine, LP)
Empiric antibiotics after cultures if admitted
This age group at risk for both "neonatal" and "community" pathogens

References

Proulx N, Fréchette D, Toye B, et al. Delays in the administration of antibiotics are associated with mortality from adult acute bacterial meningitis. QJM. 2005;98(4):291-298. doi:10.1093/qjmed/hci047 ↩
van de Beek D, Cabellos C, Dzupova O, et al. ESCMID guideline: diagnosis and treatment of acute bacterial meningitis. Clin Microbiol Infect. 2016;22 Suppl 3:S37-S62. doi:10.1016/j.cmi.2016.01.007 ↩
Thigpen MC, Whitney CG, Messonnier NE, et al. Bacterial meningitis in the United States, 1998-2007. N Engl J Med. 2011;364(21):2016-2025. doi:10.1056/NEJMoa1005384 ↩
Collaborators GBDMeningitis. Global, regional, and national burden of meningitis, 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016. Lancet Neurol. 2018;17(12):1061-1082. doi:10.1016/S1474-4422(18)30387-9 ↩
Tunkel AR, Hartman BJ, Kaplan SL, et al. Practice guidelines for the management of bacterial meningitis. Clin Infect Dis. 2004;39(9):1267-1284. doi:10.1086/425368 ↩
Rennick G, Shann F, de Campo J. Cerebral herniation during bacterial meningitis in children. BMJ. 1993;306(6883):953-955. doi:10.1136/bmj.306.6883.953 ↩
Nigrovic LE, Kuppermann N, Macias CG, et al. Clinical prediction rule for identifying children with cerebrospinal fluid pleocytosis at very low risk of bacterial meningitis. JAMA. 2007;297(1):52-60. doi:10.1001/jama.297.1.52 ↩ ↩²
Martin NG, Defres S, Willis L, et al. Paediatric meningitis in the conjugate vaccine era and a novel clinical decision model to predict bacterial aetiology. J Infect. 2024;88(5):106145. doi:10.1016/j.jinf.2024.106145 ↩ ↩²
Dubos F, Korczowski B, Aygun DA, et al. Serum procalcitonin level and other biological markers to distinguish between bacterial and aseptic meningitis in children: a European multicenter case cohort study. Arch Pediatr Adolesc Med. 2008;162(12):1157-1163. doi:10.1001/archpedi.162.12.1157 ↩ ↩²
Castagno E, Aguzzi S, Rossi L, et al. Clinical predictors and biomarkers in children with sepsis and bacterial meningitis. Pediatr Emerg Care. 2023;39(5):311-317. doi:10.1097/PEC.0000000000002865 ↩
Leber AL, Everhart K, Balada-Llasat JM, et al. Multicenter Evaluation of BioFire FilmArray Meningitis/Encephalitis Panel for Detection of Bacteria, Viruses, and Yeast in Cerebrospinal Fluid Specimens. J Clin Microbiol. 2016;54(9):2251-2261. doi:10.1128/JCM.00730-16 ↩ ↩²
Brouwer MC, McIntyre P, Prasad K, van de Beek D. Corticosteroids for acute bacterial meningitis. Cochrane Database Syst Rev. 2015;2015(9):CD004405. doi:10.1002/14651858.CD004405.pub5 ↩ ↩² ↩³ ↩⁴
Sudo RYU, Câmara MCC, Kieling SV, et al. Shorter versus longer duration of antibiotic treatment in children with bacterial meningitis: a systematic review and meta-analysis. Eur J Pediatr. 2024;183(1):61-71. doi:10.1007/s00431-023-05275-8 ↩ ↩² ↩³ ↩⁴
Liu Y, Feng Y, Guo Y, et al. Clinical predictors of poor outcome of bacterial meningitis in infants less than 90 days: a systematic review. Front Pediatr. 2024;12:1414778. doi:10.3389/fped.2024.1414778 ↩

Clinical board

Urgent signals

Editorial and exam context

Pediatric Bacterial Meningitis

Quick Reference Card

Critical Time-Sensitive Actions

Emergency Recognition Triad

Age-Specific Pathogens: The Critical Three

CSF Interpretation at a Glance

Empiric Antibiotic Dosing Quick Reference

Definition and Overview

Core Definition

Clinical Significance

Classification System

Epidemiology

Global Burden

Incidence by Age and Pathogen

Risk Factors

Mortality and Morbidity Outcomes

Pathophysiology

Mechanisms of CNS Invasion

Inflammatory Cascade

Cerebral Complications

Pathogen-Specific Virulence Factors

Clinical Presentation

Age-Specific Presentations

Neonates (less than 28 Days)

Infants (1-12 Months)

Children (> 12 Months)

Physical Examination Signs

Meningeal Signs

Assessment of Raised Intracranial Pressure

Meningococcal Disease: Special Considerations

Red Flags and Contraindications

Absolute Contraindications to Immediate LP

Indications for CT Before LP

Life-Threatening Presentations Requiring Immediate Intervention

Differential Diagnosis

Primary Differential Considerations

Mimics in Specific Populations

Diagnostic Approach

Clinical Decision Rules

Bacterial Meningitis Score (BMS)

UK-ChiMES Clinical Decision Models (2024)

Lumbar Puncture

Technique and Safety

CSF Interpretation

Traumatic LP Interpretation

Laboratory Investigations

Essential Blood Tests

CSF Studies

Imaging

Indications for Neuroimaging

Treatment

Emergency Management Algorithm

Antimicrobial Therapy

Empiric Treatment by Age

Pathogen-Directed Therapy

Adjunctive Dexamethasone

Supportive Care

Fluid Management

Seizure Management

Management of Raised ICP

Pain Management

Duration of Therapy

Complications

Acute Complications

Syndrome of Inappropriate ADH Secretion (SIADH)

Cerebral Edema and Raised ICP

Subdural Collections

Vascular Complications

Seizures

Long-term Sequelae

Hearing Loss

Neurological Sequelae

Neonatal-Specific Predictors of Poor Outcome

Neurodevelopmental Follow-up

Prevention

Vaccination

Conjugate Vaccines