• Infection and inflammation of the meninges
surrounding the brain by direct inoculation or
• can be caused by bacteria, viruses, or, rarely,
• Viral meningitis is caused principally by
entero-viruses, including coxsackieviruses,
echoviruses, and, in unvaccinated individuals,
• The organisms commonly causing bacterial meningitis :
S. pneumoniae , N. meningitidis and H. influenzae
type b .
• Incidence of H. influenzae type b meningitis has
decreased dramatically as a result of immunization.
the most frequent pathogens varied according to age
• 1 month and <3 months—GBS (39%), gram-negative
bacilli (32%), S. pneumoniae (14%), N. meningitidis
• ≥3 months and <3 years—S. pneumoniae (45%), N.
meningitidis (34%), GBS (11%), gram-negative bacilli
• ≥3 years and <10 years—S. pneumoniae (47%), N.
• ≥10 years and <19 years—N. meningitidis (55%).
• Clinical manifestations: Preceding
upper respiratory tract symptoms are
• Rapid onset is typical of S. pneumoniae and N.
• Indications of meningeal inflammation include
headache, irritability, nausea, nuchal rigidity,
lethargy, photophobia, and vomiting.
• Fever usually is present.
• Kernig and Brudzinski signs of meningeal
irritation usually are positive in children older
than 12 months of age.
• In young infants, signs of meningeal
inflammation may be minimal with only
irritability, restlessness, depressed mental
status, and poor feeding.
• Focal neurologic signs, seizures, arthralgia,
myalgia, petechial or purpuric lesions, sepsis,
shock, and coma may occur.
• Increased intracranial pressure is reflected in
complaints of headache, diplopia, and vomiting.
• A bulging fontanel may be present in infants.
• Ptosis, sixth nerve palsy , bradycardia with
hypertension, and apnea are signs of increased
intracranial pressure with brain herniation.
• Papilledema is uncommon, unless there is
occlusion of the venous sinuses, subdural
empyema, or brain abscess.
• Neurologic sequelae include focal deficits,
seizures, hearing loss, and vision impairment.
• The most common permanent neurologic
sequel is hearing loss.
Cerebrospinal Fluid Evaluation (CSF)
Normal Bacterial Viral Tuberculosis
WBC per mL 0–5 (allow up
to 30 in
100–100,000 50–1,000 100 s
45–65 Low Normal Low
20–45 High Slightly
Gram stain Negative Positive Negative Negative
• In neonates, initiate ampicillin plus
• Cefotaxime will treat GBS and gram-negative
enterics and penetrates the CSF.
• Ampicillin is mainly used for its effectiveness
against Listeria monocytogenes.
• In infants and children outside of the neonatal
age group, third-generation cephalosporin &
• Third-generation cephalosporin is generally used
empirically, as it treats pathogens most likely
recovered at this age, including S. pneumoniae,
N. meningitidis & H. influenzae type b .
• Vancomycin is added for resistant S.
• Duration of treatment is 10 to 14 days for S.
pneumoniae, 5 to 7 days for N. meningitidis, and
7 to 10 days for H. influenzae.
• Dexamethasone shown to decrease hearing loss
in those with meningitis due to H. influenzae type
b (given before or concurrently with first dose of
• Antibiotic prophylaxis of close contacts to those
with meningococcal meningitis and H. influenzae
type b meningitis is indicated.