BACTERIAL MENINGITIS

Differential Diagnosis

Bacterial, viral, or other infectious agents: drug-induced, neoplasic, granulomatous, infectious endocarditis, collagen-vascular diseases, subdural hemorrhage, subarachnoid hemorrhage

Comments on Treatment

Cefoperazone (cephalosporins, 3rd Generation) does not have reliable CSF penetration  and should not be used in meningitis.

Chloramphenicol is used only in patients with a history of anaphylaxis to penicillin.

Presentation and Treatment

Empiric Treatment, CSF Gram Stain Negative, Patient Immunocompetent

Preterm to <1 month Usual microorganisms:  Group B Streptococci (strep. agalactiae), E. coli enterohemorrhagic, listeria monocytogenes, klebsiella species, listeria monocytogenes, other gram-positive and negative Suggested therapy: Primary :  ampicillin 50 mg/kg IV q12-6h (according to weight and age) and cefotaxime 50 mg/kg IV q12-q8h (according to weight and age) Alternative :  ampicillin 50 mg/kg IV q12-6h (according to weight and age) and gentamicin 2.5 mg/kg Iv q12-24 (according to weight and age) 1 to 3 month Usual microorganisms:  strep. pneumoniae, neisseria meningitidis, haemophilus influenzae (rare since vaccination available), and microorganisms from <1month (rare) Suggested therapy: Primary : ampicillin 50 mg/kg IV q12-6h (according to weight and age) and cefotaxime 200 mg/kg/day div. in q6-8h or ceftriaxone 100 mg/kg/day IV div. in q12h and  dexamethasone 0.4 mg/kg IV q12h X 2 days or dexamethasone 0.15 mg/kg IV q6h for 4 days Alternative :   vanco 15 mg/kg IV q6h and  cefotaxime 200 mg/kg/day div. in q6-8h or ceftriaxone 100 mg/kg/day IV div. in q12h and dexamethasone 0.4 mg/kg IV q12h for 2 days or dexamethasone 0.15 mg/kg IV q6h for 4 days 3 month to 50 years Usual microorganisms:  strep. pneumoniae, neisseria meningitidis, haemophilus influenzae (very rare), listeria monocytogenes (rare if immunocompetent) Suggested therapy: Primary :  Children:  cefotaxime 200 mg/kg/day div. in q6-8h or ceftriaxone 100 mg/kg/day IV div. in q12h and   (dexamethasone 0.4 mg/kg IV q12h for 2 days or dexamethasone 0.15 mg/kg IV q6h for 4 days) ± [vanco 15 mg/kg IV q6h ( if drug-resistant strep. pneumoniae)] Adults:  cefotaxime 2 g IV q8h or ceftriaxone 2g IV qd and (dexamethasone 0.4 mg/kg IV q12h for 2 days or dexamethasone 0.15 mg/kg IV q6h for 4 days) ± [vanco 1 g IV q12h (if drug-resistant strep. pneumoniae)] Alternative :   meropenem 1 g IV q8h (for children, use 120 mg/kg/day div. in q8h, max 3 g/day) and  dexamethasone 0.4 mg/kg IV q12h X 2 days or dexamethasone 0.15 mg/kg IV q6h X 4 days ± [vanco 1 g IV q12h (if drug-resistant strep. pneumoniae)] >50 years or co-morbidity (alcoholism or debilitating diseases)

Usual microorganisms: 

strep. pneumoniae, listeria monocytogenes, gram-negative bacilli

Suggested therapy:

Primary : 
ampicillin 2g IV q6h and
cefotaxime 2 g IV q8h or ceftriaxone 2g IV qd and 
dexamethasone 0.4 mg/kg IV q12h for 2 days
Alternative :
meropenem 1 g IV q8h and
dexamethasone 0.4 mg/kg IV q12h for 2 days

Post neurosurgery or head trauma   

Usual microorganisms: 

strep. pneumoniae(most frequent if CSF leak), staph. aureus, haemophilus influenzae,  enterobacteriaceae, pseudomonas aeruginosa, gram-negative bacilli, , staph. epidermidis, candida species, 

Suggested therapy:

Primary : 
vanco 1 g IV q12h (ad C/S then towards specific organism) and 
ceftazidime 2g IV q8h
Alternative :
meropenem 1 g IV q8h
 

Ventriculitis or meningitis infected ventrilo-peritoneal/atrial shunt   

Usual microorganisms: 

staph. epidermidis, staph. aureus, enterobacteriaceae, diphtheroids (rare)

Suggested therapy:

Primary : 
Children: vanco 15 mg/kg IV q6h + (cefotaxime 50 mg/kg IV q6h or ceftriaxone 50 mg/kg IV q12h).
Adult: vanco 1 g IV q12h + RIF 600 mg IV/PO qd

Any age, immunocompromised (not HIV)

Usual microorganisms:

listeria monocytogenes, gram-negative bacilli

Suggested therapy:

Primary : 
ampicillin 2g IV q6h and 
ceftazidime 2g IV q8h

Empiric Treatment, CSF Gram Stain Positive

Gram-positive diplococci   

Usual microorganisms: 

strep. pneumoniae

Suggested therapy:

Primary : 
vanco 1 g IV q12h and 
cefotaxime 2 g IV q8h or ceftriaxone 2g IV qd ± 
dexamethasone 0.4 mg/kg IV q12h for 2 days

Gram-negative diplococci 

Usual microorganisms: 

neisseria meningitidis

Suggested therapy

Primary : 
pen G  4 million units IV q4h
If allergy penicillin :  
chloramphenicol 50 mg/kg/day IV  div in doses q6h (max dose: 4 g/day)

Gram-negative bacilli

Usual microorganisms: 

haemophilus influenzae, enterobacteriaceae, pseudomonas aeruginosa

Suggested therapy:

Primary : 
ceftazidime 2 g IV q8h and 
gentamicin 2 mg/kg IV loading then 1.7 mg/kg IV q8h

Specific Treatment: Strep. Pneumonia

pen G MIC <0.1 ug/ml

Suggested therapy:

pen G 4 million units IV q4h

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