Meningitis

Question 1

What is the pathogenesis of meningitis

Answer 1

Bact gain entry into body via
- Invasion of mucosal surface –> hematogenous spread to brain
- Penetrating head trauma
- Anatomic defects in meninges
- Prev neurosurgical procedures

Colonisation of bact in meninges of a susceptible host
Overgrowth –> meningitis

Question 2

What is the general aetiology of meningitis?

Answer 2

Septic menigitis: Bact
Aseptic meningitis:
Viral
Other microorg: fungal, parasitic, mycobact, syphilis
Drugs (e.g. cotrimoxazole, ibuprofen - irritate meninges, inflamm)
Autoimmune diseases

Question 3

What are the symptoms of meningitis?

Answer 3

Fever, chills, rigors
Alt mental status
Classic triad: Headache, Backache, Nuchal (neck) rigidity
NV
Anorexia
Poor feeding habits
Photophobia
Petechiae or purpura (Neisseria meningitidis)

Question 4

What are the signs of meningitis?

Answer 4

WBC, CRP, procalcitonin

Kernig’s sign = hamstring extended, thigh perpendicular to trunk leads to severe back pain

Brudzinski sign = when head held up, natural reflex of flexion of hip and knee

Bulging fontane = CSF accum

Question 5

Differentiate CSF in normal vs bact meningitis vs viral meningitis.

Answer 5

Glucose:
Normal - glucose:plasma > 0.66
Bact meningitis - glucose:plasma low <0.4
Viral meningitis - glucose:plasma normal to low

Proteins:
Normal - Low <0.4 g/L
Bact meningitis - Elevated >1.5g/L
Viral meningitis - Normal to mildly raised

Wbc:
Normal - <5 cells/mm^3
Bact meningitis - elevated, mostly neutrophils >100 cells/mm^3
Viral meningitis - elevated, mostly lymphocytes 5-1000 cells/mm^3

Question 6

How do we diagnose meningitis?

Answer 6

Hx & physical exams
Blood cultures
Lumbar puncture: elevated opening P, CSF composition, gram stain & culture
Radiology

Question 7

When do we do radiology for meningitis?

Answer 7

To evaluate for complications or disease progression, differential diagnosis.
If pt is unconscious or low alertness
Do prior to lumbar puncture where there is concern for brain shift

Question 8

What are the bugs to cover for meningitis in neonates (<1mo)?

Answer 8

Group B streptococcus (S. aagalactiae)
E. coli
Listeria monocytogenes

Question 9

What are the bugs to cover for meningitis in infants and children (1-23 mo)?

Answer 9

Group B streptococcus (S. agalactiae)
E. coli
S. pneumoniae
Neisseria meningitidis

Question 10

What are the bugs to cover for children and adults (2-50y)?

Answer 10

S. pneumoniae, Neisseria meningitidis

Question 11

What are the bugs to cover for elderly?

Answer 11

S. pneumoniae
Neisseria meningitidis
Listeria monocytogenes
Aerobic gram -ve

Question 12

What is the recommended regimen for neonates (<1mo)?

Answer 12

IV ceftriaxone AND IV ampicillin (for listeria)

Question 13

What is the recommended regimen for infants and children (1-23mo)?

Answer 13

IV ceftriaxone AND IV vancomycin

Question 14

What is the recommended regimen for children and adults (2-50y)?

Answer 14

IV ceftriazone AND IV vancomycin

Question 15

What is the recommended regimen for elderly?

Answer 15

IV ceftriaxone AND IV vancomycin AND IV ampicillin (for listeria)

Question 16

What is the recommended regimen for culture directed Listeria monocytogenes?

Answer 16

IV ampicillin or penicillin
Penicillin allergy: IV cotrimoxazole, meropenem

Question 17

What is the recommended regimen for culture directed S. pneumoniae?

Answer 17

Penicillin susceptible: IV Pen G or ampicillin
Penicillin resistant, cephalosporin susceptible: Ceftriaxone
Penicillin, cephalosporin resistant: IV vancomycin AND rifampicin

Question 18

What is the recommended regimen for culture directed Neisseria meningitidis?

Answer 18

Penicillin susceptible: IV Penicillin G or ampicillin
Penicillin resistant or mild allergy: IV Ceftriaxone

Question 19

What is the recommended regimen for culture directed Group B Streptococcus (S. agalactiae)?

Answer 19

Penicillin susceptible: IV Pen G or ampicillin
Penicillin resistant or mild allergy: IV Ceftriaxone

Question 20

What is the recommendation for adjunctive corticosteroid therapy?

Answer 20

10 mg Q6H for up to 4d, 10-20min before first dose of abx.
Only for H. influenzae and S. pneumoniae meningitis

Question 21

What are the benefits of adjunctive corticosteroid thera in H. influenzae and S. pneumoniae meningitis?

Answer 21

Less hearing loss & other neurologic sequelae
Decreased mortality (S. pneumoniae)

Question 22

What are the concerns for adjunctive corticosteroid therapy in H. influenzae and S. pneumoniae meningitis?

Answer 22

May decrease abx penetration.
ADR: mental status changes, hyperglycemia, HTN

Question 23

What is the recommendation for antibiotic chemoprophylaxis with respect to meningococcal meningitis?

Answer 23

Rifampicin
Adults: 600 mg Q12H, four doses
Children: 10 mg/kg Q12H, four doses
Infants: 5 mg/kg Q12H, four doses

Ciprofloxacin 500 mg once daily, one dose
Ceftriaxone 140-250 mg IM, one dose

Question 24

What are the risk factors for meningitis?

Answer 24

Head trauma
Neurosurgery
CSF shunts
CSF fistula or leaks
Abnormalities in meninges (Congenital defects)
Drugs
Splenectomised pts
Immunosuppression

Question 25

What is the duration of treatment for Listeria monocytogenes?

Answer 25

> =21d

Question 26

What is the duration of treatment for Neisseria meningitidis?

Answer 26

5-7d

Question 27

What is the duration of treatment for Group B Streptococcus (S. agalactiae)?

Answer 27

14-21d

Question 28

What is the duration of treatment for S. pneumoniae?

Answer 28

10-14d

Question 29

How do we de-escalate if there is -ve culture?

Answer 29

Treat with empiric abx for at least 14d. May be extended dep on condition of pt