Bacterial Meningites

Question 1

What are the risk factors associated with bacterial meningites?

Answer 1

1. Head trauma
2. CNS shunts
3. Neurosurgical patients
4. CSF fistula/leaks
5. Local infections: sinusitis, otitis media, pharyngitis
6. Immunosuppressed
7. Splenectomized patients
8. Congenital defects

Question 2

Describe the pathophysiology of bacterial meningites

Answer 2

Risk factors predispose patients of infection and colonization by bacteria causing meningites

Bacteria then gains entry by various mechanisms:
1. Invasion of mucosal surface then hematogenous spread to brain
2. Spread from para-meningeal focus
3. Penetrating head trauma
4. Anatomic defect in meninges
5. Previous neurosurgical procedures

Bacteria enter CNS and colonize the meninges

Question 3

Describe the clinical presentations of bacterial meninges

Answer 3

Fever and chills
Traid of headache, backache and neck rigidity
Mental status change
Photophobia
Nausea and vomiting
Petechiae and purpura

Infants having poor feeding habits

Question 4

What are some physical signs of patients with bacterial meningitis?

Answer 4

Kernig sign
Brudzinski sign
Bulging fontane

Question 5

How is bacterial meningitis diagnosed?

Answer 5

Lumbar puncture to check for CSF composition, CSF gram stain and culture and CSF PCR

Question 6

What are the components of CSF to look out for in diagnosing bacterial meningitis?

Answer 6

Glucose
Protein
WBC
Physical observation of CSF

Question 7

What is the CSF composition in one with bacterial meningitis?

Answer 7

Glucose low
Protein raised
WBC raised with predominant neutrophils
Turbid fluid

Question 8

What is the CSF composition in one with viral meningitis?

Answer 8

Glucose: normal to slightly low
Protein: Normal to mildly raised
WBC: Raised with predominant leukocytes
Clear fluid

Question 9

Is radiology often done for bacterial meningitis?

Answer 9

No. Usually done to evaluate differential diagnosis and complications

Question 10

Why is a radiology test done before the lumbar puncture?

Answer 10

Concerns of brain shift due to mass lesions and also potential risk of brain hernia during lumbar puncture

Question 11

What are the different age groups in bacterial meningitis?

Answer 11

Neonates
Infants and children
Children and adults
Adults > 50y

Question 12

What are the type of pathogens identified for bacterial meninigitis in neonates?

Answer 12

Group B Streptococcus
E.Coli
Listeria monocytogenes

Question 13

What are the type of pathogens identified for bacterial meninigitis in infants and children (1-23 months old)?

Answer 13

Group B Streptococcus
E.coli
Neisseria meningitidis
S.Pneumoniae

Question 14

What are the type of pathogens identified for bacterial meninigitis in children and adults (2-50 years)?

Answer 14

Neisseria meningitidis
S.Pneumoniae

Question 15

What are the type of pathogens identified for bacterial meninigitis in adults > 50 y?

Answer 15

Neisseria meningitidis
S.Pneumoniae
Listeria monocytogenes
Other gram negatives including E.coli, Klebsiella

Question 16

How is empiric therapy initiated for neonates?

Answer 16

Ceftriaxone + Ampicillin

Question 17

How is empiric therapy initiated for infants and children (2-23 months)?

Answer 17

Ceftriaxone + Vancomycin

Question 18

How is empiric therapy initiated for children and adults?

Answer 18

Ceftriaxone + Vancomycin

Question 19

How is empiric therapy initiated for adults > 50y?

Answer 19

Ceftriaxone + Vancomycin + Ampicillin

Question 20

What should be done upon receiving AST results? What antibiotic therapy to initiate if AST results negative?

Answer 20

Begin culture-directed therapy

If AST negative, to treat empiric antibiotic for more than or equal to 14 days

Question 21

What antibiotics should be considered for S.Pneumoniae?
Format your answer to consider penicillin susceptible, penicillin resistant and cephalosporin resistant strains. State the duration of therapy.

Answer 21

Penicillin G/ Ampicillin

Penicillin resistant: Ceftriaxone

Penicillin and cephalosporin resistant: Vancomycin + Rifampicin

Duration: 10-14 days

Question 22

What antibiotics should be considered for Neisseria meningitidis?
Format your answer to consider penicillin susceptible, penicillin resistant strains. State the duration of therapy.

Answer 22

General: Penicillin G / Ampicillin

Penicillin resistant OR beta lactam allergy: ceftriaxone

Duration: 5-7 days

Question 23

What antibiotics should be considered for Listeria monocytogenes?
Format your answer to consider penicillin susceptible, penicillin resistant and cephalosporin resistant strains. State the duration of therapy.

Answer 23

General: Penicillin G / Ampicillin

Penicillin resistant / allergy: Co-trimoxazole; Meropenem

Duration > 21 days

Question 24

What antibiotics should be considered for Group B Streptococcus?
Format your answer to consider penicillin susceptible, penicillin resistant and cephalosporin resistant strains. State the duration of therapy.

Answer 24

General: Penicillin G/ Ampicillin

Penicillin resistant / mild allergy: Ceftriaxone

Question 25

What other adjunctive treatment can I consider for bacterial meningitis? Which group of patients can benefit from this?

Answer 25

Adjunctive dexamethasone therapy Good for patients more than 6 weeks old with H.Influenzae or S.Pnuemoniae bacterial meningitis

Question 26

What dose and how should dexamethasone be administered?

Answer 26

10mg every 6 hours for 4 days Administer 10-20 minutes before / at same time as first dose of antibiotics

Question 27

What are the benefits and risks of initiating dexamethasone?

Answer 27

Benefits: Decreasing hearing loss and other neurologic sequelae from H.Influenzae infection; decreased mortality in S.Pneumoniae meningitis Risks: Decreases antibiotic penetration and increased ADR

Question 28

How should pharmacist monitor patient's response?

Answer 28

Duration of improvement should be seen within 48h If not, use brain imaging to check for cerebrovascular complications Check for adverse drug reactions and advice patient on long term issue of morbidity

Question 29

Discuss the criterias for antibiotics used in meningitis

Answer 29

Should distribute to CSF and achieve adequate CSF concentration Need high dose and IV administration Should be active against likely pathogens Does not aggravate CNS morbidity

Question 30

Who are eligible for chemoprophylaxis of meningitis?

Answer 30

Close contact with meningococcal disease due to household / day care contact Exposed to oral secretions of index case

Question 31

What are the possible chemoprophylaxis in infants and children for bacterial meningitis? List dose, duration and frequency

Answer 31

Infant - 5mg /kg every 12 hours (4 doses) Children - 10 mg/kg every 12 hours (4 doses)

Question 32

What are the possible chemoprophylaxis in adults for bacterial meningitis? List dose, duration and frequency

Answer 32

Rifampicin 600mg every 12 hours (4 doses) Ciprofloxacin 500mg orally (1 dose) Ceftriaxone 125-250mg IM (1 dose)