Previously healthy 4-year-old boy with fever and lethargy x 24 hours
•On examination reduced level of consciousness, nuchal rigidity (+ve Kernig, Brudzinsky)
•CSF findings
▫WBC 265 WBC x106/L (70% polymorphs)
▫RBC 2 x106/L
▫Glucose 0.2 mmol/L

•What are the most common pathogens? (s pneumo, n meningitidis - for meningitis)
•What empiric antibiotic therapy should be administered and why?
▫Suspected organisms
▫Potential for antibiotic resistance
▫CSF penetration
>>Ceftriaxone (or cefotaxime) + vancomycin

Acute bacterial meningitis
>>Infant (much harder to assess nuchal rigidity)
•Symptoms
▫Fever, poor feeding, vomiting, irritability, lethargy, inconsolable crying
•Signs
▫Bulging anterior fontanelle (absence doesn't rule out)
▫Diminished activity
▫Septic appearance
▫Petechial rash
•Typically non-specific
>>Child (> 2 years)
•Symptoms
▫Fever, headache, vomiting, back/neck pain, photophobia, confusion, disorientation
•Signs
▫Neck stiffness
▫Kernig & Brudzinski signs
▫Focal neurological signs
▫Petechial rash

CSF findings (normal - abnormal)
>>WBC (x106/L) - neo (0-30), >1m (<5) - bact (50-50000), viral (20-2000), TB (100-500)
>>% PMN - neo (<60), >1m (0) - bact (95), viral (<30), TB (<30)

Acute bacterial meningitis - Empiric antibiotic therapy
>>neonate - Group B streptococcus, Gram negative bacilli (E. coli), Listeria spp. - Ampicillin + cefotaxime (ampi mainly needed for listeria b/c cefo won't cover)
>>1-3 mo. - Overlap of “neonatal” organisms or those seen in older children - Ampicillin + cefotaxime ± vancomycin
>>. >3 mo. - Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae type b - Ceftriaxone + vancomycin