ACUTE BACTERIAL MENINGITIS

Question 1

Organisms most often responsible for community-acquired bacterial meningitis

Answer 1

Streptococcus pneumoniae (~50%)
Neisseria meningitidis (~25%)
Group B streptococci (~15%)
Listeria monocytogenes (~10%)
Haemophilus influenzae type b (<10%)

Question 2

The most common cause of meningitis in adults >20 years of age

Answer 2

S. pneumoniae

Question 3

The most important condition that increases the risk of pneumococcal meningitis

Answer 3

Pneumonoccal pneumonia

Question 4

Important causes of meningitis that occurs following invasive neurosurgical procedures

Answer 4

S. aureus and coagulase-negative staphylococci

Question 5

TRUE OR FALSE: The neurologic manifestations and complications of bacterial meningitis result from the immune response to the invading pathogen

Answer 5

TRUE - The neurologic manifestations and complications of bacterial meningitis result from the immune response to the invading pathogen

* As a result, neurologic injury can progress even after the CSF has been sterilized by antibiotic therapy.

Question 6

The classic clinical triad of meningitis

Answer 6

fever, headache, and nuchal rigidity

Question 7

The preferred imaging modality for TB meningitis

Answer 7

MRI

• MRI is preferred over CT because of its superiority in demonstrating areas of cerebral edema and ischemia
• diffuse meningeal enhancement is often seen after the administration of gadolinium

Question 8

The typical CSF profile with viral CNS infections

Answer 8

lymphocytic pleocytosis with a normal glucose

Question 9

Most common etiologic agent for community-acquired bacterial meningitis

Answer 9

S. pneumoniae and N. meningitidis

Question 10

Empirical therapy of community-acquired suspected bacterial meningitis in adults include what drugs

Answer 10

Dexamethasone
Third- or fourth-generation cephalosporin (e.g., ceftriaxone, cefotaxime, or cefepime)
Vancomycin
Acyclovir as HSV encephalitis is the leading disease in the differential diagnosis
Doxycycline during tick season to treat tickborne bacterial infections

Question 11

What drug should be added to the empirical regimen for coverage of L. monocytogenes in individuals <3 months of age, those >55, or those with suspected impaired cell-mediated immunity?

Answer 11

Ampicillin

Question 12

The most common etiologic organisms for hospital-acquired meningitis, and particularly meningitis following neurosurgical procedures

Answer 12

Staphylococci and gram-negative organisms including P. aeruginosa

Question 13

Regimen for hospital acquired meningitis, post traumatic or post neurosurgery meningitis

Answer 13

Ampicllin + Ceftazidime or Meropenem + Vancomycin

Question 14

Empirical regimen for age and adults of any age with alcoholism or other debilitating illnesses

Answer 14

Ampicillin + Cefotaxime, Ceftriaxone or Cefepime + Vancomycin

Question 15

Empirical regimen for adults < 55 years old

Answer 15

Cefotaxime, Ceftriaxone or Cefepime + Vancomycin

Question 16

This drug remains the antibiotic of choice for meningococcal meningitis caused by susceptible strains

Answer 16

Penicillin G

Question 17

In meningococcal meningitis, what is the chemoprophylaxis regimen for the index case and all close contacts?

Answer 17

2-day regimen of rifampin 600 mg every 12 h for 2 days in adults

• Alternatively, adults can be treated with one dose of azithromycin (500 mg) or one intramuscular dose of ceftriaxone (250 mg)

Question 18

TRUE OR FALSE: Antimicrobial therapy of pneumococcal meningitis is initiated with a cephalosporin (ceftriaxone, cefotaxime, or cefepime) and vancomycin

Answer 18

TRUE

Question 19

When should repeat LP be performed in patients with S. pneumonia meningitis?

Answer 19

Repeat LP 24–36 h after the initiation of antimicrobial therapy to document sterilization of the CSF.

Question 20

TRUE OR FALSE: Failure to sterilize the CSF after 24–36h of antibiotic therapy should be considered presumptive evidence of antibiotic resistance.

Answer 20

TRUE

Question 21

If the CSF isolate of N. meningitidis is resistant to penicillin and ampicillin, what alternative drug(s) should be given to the patient?

Answer 21

Cefotaxime or ceftriaxone should be substituted for penicillin.

• 7-day course of intravenous antibiotic therapy is adequate