4. Bacterial Meningitis

Question 1

How do pathogens get into the CSF?

Answer 1

Haematogenously, esp from nasopharynx
Adjacent focus of infection
From nasopharynx via bony defect or head injury

Question 2

Where do pathogens replicate in meningitis?

Answer 2

Subarachnoid space

Question 3

What are the bacterial causes of meningitis?

Answer 3

Strep pneumo
N. meningitidis
Haemophilus

Question 4

What are the bacterial causes of meningitis in the neonate?

Answer 4

Group B strep
E.coli and other gram negative bacilli
Listeria

Question 5

What are the risk factors for meningitis?

Answer 5

No spleen (Hib, pneumo, meningitidis)
Diabetes and alcoholism (pneumo)
Immunosuppression (listeria and crypto)
Fracture or defect of skull (recurrent pneumo)
Complement deficiency (recurrent neisseria)
Pregnancy (listeria)

Question 6

What is the gram stain of neisseria meningitidis?

Answer 6

Gram negative diplcocci

Question 7

What is the transmission of neisseria meningitidis?

Answer 7

Droplet

Question 8

What is the gram stain of strep pneumo?

Answer 8

Gram positive diplococci

Question 9

What is severe haemophilus influenza meningitis associated with?

Answer 9

Deafness
Seizures
intellectual impairment

Question 10

What is the gram stain of listeria?

Answer 10

Gram positive bacillus

Question 11

What is the gram stain of haemophilus?

Answer 11

Gram negative coccobacillus

Question 12

What kind of pathogen is cryptococcus?

Answer 12

Encapsulated yeast

Question 13

What is the predominant feature of cryptococcus meningitis?

Answer 13

Headaches in an immunocompromised person

Question 14

How is cryptococcus meningitis detected?

Answer 14

Antigen detection in blood and CSF

CSF microscopy with india ink

Question 15

What extra-cranial symptoms are associated with leptospirosis infection?

Answer 15

Renal and hepatic failure

Question 16

What are the complications of meningitis?

Answer 16

Hearing loss
Subdural abscess
Cranial nerve palsies
Intellectual disability
Hydrocephalus and raised ICP
Dissemination

Question 17

How is a diagnosis of meningitis made?

Answer 17

Clinical assessment most important

LP, blood for culture and PCR

Question 18

What are the contraindications for LP?

Answer 18

Raised ICP

Coagulopathy

Question 19

What is seen in CSF in bacterial meningitis?

Answer 19

Very high protein
Low glucose
High polymorphs, lymphocytes in leptospirosis and TB

Question 20

What is the management of meningitis?

Answer 20

IV antibiotics and steroids
Treat complications, supportive etc
Notify public health

Question 21

What are the empiric antibiotics for an infant under 3 months old?

Answer 21

Amoxicillin
Ceftriaxone
Gentamicin

Question 22

What are the empiric antibiotics for children and adults?

Answer 22

Ceftriaxone and vancomycin

Add amoxicillin if elderly, immunocompromised or pregnant

Question 23

What is the minimum duration of antibiotics in meningococcal meningitis?

Answer 23

7 days

Question 24

What is the minimum duration of antibiotics in haemophilus meningitis?

Answer 24

10 days

Question 25

What is the minimum duration of antibiotics in pneumococcal meningitis?

Answer 25

14 days

Question 26

What is the minimum duration of antibiotics in group B strep meningitis?

Answer 26

14-21 days

Question 27

What is the minimum duration of antibiotics in listeria or aerobic gram negative meningitis?

Answer 27

21 days

Question 28

Which pathogens can be vaccinated against?

Answer 28

N. meningitidis Hib Strep pneumo

Question 29

Which groups are prophylactic antibiotics used in?

Answer 29

Asplenism (penicillin for strep pneumo) | Close contacts with rifampicin for meningococcal and Hib

Question 30

What precautions are used for a patient with meningitis?

Answer 30

Droplet

Question 31

What pathogens cause cerebral abscesses?

Answer 31

Strep and staph Aerobic gram negatives and anaerobes Toxoplasma gondi Aspergillosis

Question 32

What are the clinical effects of cerebral abscess?

Answer 32

Headache, seizures Nausea and vomiting, altered mental state Signs of infection

Question 33

How is a cerebral abscess diagnosed?

Answer 33

``` Avoid LP due to high ICP CT/MRI Gram stain and culture of abscess fluid PCR Blood culture ```

Question 34

What is the management of a cerebral abscess?

Answer 34

Surgical aspiration and drainage Cefotaxime, metronidazole and flucloxacillin empirically Treat underlying cause

Question 35

Which pathogens are steroids recommended to be given for?

Answer 35

Hib Pneumo TB

Question 36

When should steroids be given?

Answer 36

Before or with first round of antibiotics

Question 37

What is the most common cause of cerebral abscesses?

Answer 37

Strep mitis