|  | Family Health | Men's Health

Pyogenic (Bacterial) Meningitis: Causes, Symptoms, Diagnosis & Emergency Treatment

Pyogenic meningitis is a life-threatening bacterial infection of the meninges (protective membranes covering the brain and spinal cord). It is a medical emergency requiring immediate IV antibiotics—delay increases mortality and neurologic sequelae.

Common Pathogens by Age Group

AgeMost Common Causes
Neonates (<1 mo)Group B Strep, E. coli, Listeria
Infants/Children (1 mo–18 yr)S. pneumoniae, N. meningitidis, H. influenzae type b (rare if vaccinated)
AdultsS. pneumoniae, N. meningitidis
Elderly/ImmunocompromisedS. pneumoniae, Listeria, Gram-negatives

Classic Triad (present in ~2/3 of adults)

  1. Fever
  2. Nuchal rigidity (stiff neck)
  3. Altered mental status (confusion, lethargy)

Additional Symptoms

  • Severe headache (often "worst of life")
  • Photophobia (light sensitivity)
  • Nausea/vomiting
  • Seizures
  • Focal neurologic deficits
  • Petechial/purpuric rash (meningococcemia)
  • Infants: bulging fontanelle, poor feeding, irritability, high-pitched cry, hypothermia

Diagnosis

  1. Lumbar Puncture (LP) – CSF Analysis: Do not delay antibiotics for imaging unless focal signs/papilledema/immunocompromise.
    • Opening pressure: Elevated (>180 mmH2O)
    • WBC: High (usually >1000/μL, neutrophilic predominance)
    • Protein: Elevated (>100 mg/dL)
    • Glucose: Low (<40 mg/dL or CSF:serum ratio <0.4)
    • Gram stain: Positive in 60–80% (pre-antibiotics)
    • Culture: Definitive (24–48h)
    • PCR/Multiplex panels: Rapid pathogen ID
  2. Blood cultures (before antibiotics)
  3. CT Head if LP contraindicated

Emergency Treatment

  • Empiric IV Antibiotics (START IMMEDIATELY):
    • Adults: Vancomycin + Ceftriaxone (or Cefotaxime) ± Ampicillin (if >50 or immunocompromised for Listeria)
    • Children: Vancomycin + Ceftriaxone/Cefotaxime
    • Neonates: Ampicillin + Cefotaxime/Gentamicin
  • Dexamethasone (0.15 mg/kg IV q6h x 4 days): Give with or before first antibiotic dose in adults with suspected pneumococcal meningitis; reduces hearing loss/neurologic sequelae.
  • Supportive: ICU monitoring, seizure prophylaxis, fluid management, treat complications (hydrocephalus, SIADH, DIC).
  • De-escalate based on culture/sensitivities.

Prevention

  • Vaccines: Hib, PCV13/20, MenACWY, MenB
  • Chemoprophylaxis for close contacts of meningococcal/Hib cases (Rifampin, Ceftriaxone, Ciprofloxacin)

Prognosis: Mortality 10–30% (higher in elderly/pneumococcal). Survivors: 20–30% have hearing loss, cognitive deficits, seizures, hydrocephalus. Early recognition and treatment save lives.

Men's Health - Related Articles