What are the symptoms and treatment of meningitis?

Meningitis Symptoms and Treatment

Clinical Presentation by Age Group

Neonates (≤28 days)

Neonatal meningitis presents with nonspecific symptoms rather than classic meningeal signs, making clinical diagnosis extremely challenging. 1, 2

• Fever is present in only 6-39% of neonatal cases, making its absence unreliable for ruling out meningitis 1, 2
• Irritability, poor feeding, and respiratory distress are the predominant presenting features 1, 2
• Pale or marble skin with hyper- or hypotonia commonly occur 1, 2
• Seizures develop in 9-34% of cases, more frequently with Group B streptococcal meningitis 1, 2
• Respiratory distress or failure is frequently an initial symptom, with 72% showing respiratory symptoms, 69% cardiovascular, and 63% neurologic signs within 24 hours of GBS meningitis onset 1
• Septic shock may accompany approximately 25% of meningitis cases 1, 2

Critical pitfall: A low threshold for lumbar puncture must be maintained in neonates with suspected infection, as clinical examination alone cannot rule out meningitis. 1

Children Beyond Neonatal Age

The younger the child, the more subtle and atypical the symptoms become. 1, 2

• Fever is the most common symptom, occurring in 92-93% of pediatric cases 1, 2
• Headache varies dramatically by age: only 2-9% in children under 1 year versus 75% in children over 5 years 1, 2
• Vomiting occurs in 55-67% of cases 1, 2
• Neck stiffness is present in 40-82% of cases 2
• Altered mental status develops in 13-56% of cases 1, 2
• Seizures occur at hospital admission in 10-56% of children 1
• Petechial and purpuric rash appears in 61% of meningococcal cases but can also occur in 9% of pneumococcal meningitis 1, 2

Adults

The classic triad of fever, neck stiffness, and altered mental status is present in only 41-51% of adult cases, making clinical diagnosis unreliable. 3, 2, 4

• Headache occurs in 58-87% of cases 2
• Fever is present in 77-97% of cases 2
• Neck stiffness appears in 65-83% of cases 2
• Altered mental status develops in 30-69% of cases 2
• Petechial rash is identified in 20-52% of adults and indicates meningococcal infection in over 90% of cases 2, 4

Diagnostic Accuracy of Clinical Signs

Clinical signs alone have poor diagnostic accuracy and cannot be used to rule out bacterial meningitis. 2, 4

• Neck stiffness sensitivity: 51% in children, only 31% in adults 3, 2
• Kernig sign sensitivity: 53% in children, 11% in adults 2
• Brudzinski sign sensitivity: 66% in children, 9% in adults 2
• Resistance to passive neck flexion is the most commonly observed meningeal sign 4
• Jolt accentuation (horizontal head rotation worsening headache) may be present 4

The absence of classic symptoms cannot exclude bacterial meningitis—maintain high clinical suspicion. 3, 2, 4

Diagnostic Approach

Cerebrospinal fluid examination via lumbar puncture remains the gold standard for diagnosis when bacterial meningitis is suspected. 3, 2, 4

• CSF should be performed unless contraindications exist, showing pleocytosis with elevated protein and low glucose 3
• CT scan should precede lumbar puncture if focal neurologic findings suggest disease above the foramen magnum 4
• Blood cultures must be obtained before initiating antibiotics 4

Treatment

Immediate empiric antibiotic therapy must be initiated for suspected bacterial meningitis—never delay antibiotics while awaiting diagnostic confirmation, as mortality remains high in untreated cases. 3

Empiric Antibiotic Regimen

• Ceftriaxone 2-4g IV daily provides coverage for the most common bacterial pathogens including S. pneumoniae, N. meningitidis, and H. influenzae 3, 5
• In neonates, intravenous doses should be given over 60 minutes to reduce the risk of bilirubin encephalopathy 5
• For children with meningitis, the initial therapeutic dose is 100 mg/kg (not exceeding 4 grams), followed by 100 mg/kg/day (not exceeding 4 grams daily) 5
• Therapy should generally continue for at least 2 days after signs and symptoms resolve, with usual duration of 4-14 days; complicated infections may require longer treatment 5
• For S. pyogenes infections, therapy must continue for at least 10 days 5

Special Considerations

• Ceftriaxone is contraindicated in neonates requiring calcium-containing IV solutions due to precipitation risk 5
• When Chlamydia trachomatis is a suspected pathogen in pelvic inflammatory disease or gynecologic infections, appropriate antichlamydial coverage must be added, as cephalosporins have no activity against this organism 5, 6
• Cefotaxime is an alternative cephalosporin with similar coverage for CNS infections caused by N. meningitidis, H. influenzae, S. pneumoniae, K. pneumoniae, and E. coli 6

Common Causative Organisms by Age

• Neonates: Group B Streptococcus and E. coli predominate 1
• Children beyond neonatal age: S. pneumoniae and N. meningitidis (primarily serogroup B) are most common 1
• Adults: S. pneumoniae is the most common cause; N. meningitidis in adolescents; L. monocytogenes in elderly and immunocompromised patients 1