Bacterial Meningitis Flashcards
In SA which populations have the highest rate of bacterial meningitis?
<1yo
Follow by 1-4yo
Which causes of bacterial meningitis are vaccine-preventable?
S. pneumo
Haeif B
Neime
Strag
Which organisms have the highest risk for morbidity?
STRPN -> HAEIF -> NEIME
What are the risk factors for bacterial meningitis?
- Immunodeficiencies
- hereditary
- asplenia
- malignancies
- HIV
- medications
- CKD, DM, alcoholism, liver disease - Anatomical defects
- cranium
- sinuses
What is the definition of meningitis?
Meningeal inflammation with abnormal WBCs in CSF (>5 WBC OR any lymphocytes)
How is bacterial meningitis transmitted?
Droplet spread
Discuss the routes of meningitis
- Haematogenous (BBB, BCB)
- Direct invasion
- Neural centripetally
Discuss the pathogenesis of bacterial meningitis
- Nasopharyngeal colonisation -> invasion -> bacteremia
- Meningeal invasion -> replication in subarachnoid space -> release of bacterial components (LPS, cell wall)
- Damage to microvascular endothelium -> increased BBB permeability -> vasogenic edema
- Cerebral vasculitis
- Subarachnoid space inflammation -> CSF outflow resistance -> incensed ICP
What are the bacterial and host factors regarding mucosal colonisation that attribute to bacterial meningitis pathogenesis?
Bacterial
- fimbriae
- IgA protease
Host
- mucosal colonisation
- secretory IgA
- cilia
What are the bacterial and host factors regarding intravascular survival that attribute to bacterial meningitis pathogenesis?
Bacteria
- polysaccharide capsule (antiphagocytic)
Host
- complement activation
- specific antibodies
What are the bacterial and host factors regarding meningeal invasion that attribute to bacterial meningitis pathogenesis?
Bacteria
- fimbriae
- lipoteichoic acid
Host
- BBB
- BCB
What are the bacterial and host factors regarding survival in subarachnoid space that attribute to bacterial meningitis pathogenesis?
Bacteria
- polysaccharide capsule
Host
- poor opsonic activity
What are the clinical features of acute bacterial meningitis in adults?
Fever
Headache
Neck stiffness
Altered GCS
Vomiting
Photophobia
What are the clinical features of acute bacterial meningitis in infants?
Irritability
Poor feeding
Bulging fontanelles
Hypothermia
What is aseptic meningitis?
Lymphocytic pleocytosis without an apparent cause on CSF
What are some causes of aseptic meningitis
Drugs
Autoimmune
Vaccines
Malignancies
What is the hallmark of acute encephalitis?
Diffuse involvement of cerebral cortex
What are the common bacterial meningitis pathogens in neonates?
S. agalctiae
E. coli
L. monocytogenes
What are the common bacterial meningitis pathogens in 1-23m?
S. agalactiae
E. coli
H. influenzae
S. pneumo
N. meningitidis
What are the common bacterial meningitis pathogens in 2-50y?
S. pneumo
N. meningitidis
What are the common bacterial meningitis pathogens in >50y?
S. pneumo
N. meningitidis
H. influenza (some)
L. monocytogenes
Aerobic GNBs
What are the common bacterial meningitis pathogens in immunocompromised patients?
S. pneumo
N. meningitidis
L. monocytogenes
Aerobic GNBs (including pseudo)
What are the common bacterial meningitis pathogens in basilar skull fractures?
S. pneumo
H. influenza
S. pyogenes
Exposure to the nasopharynx
What are the common bacterial meningitis pathogens in head trauma?
S. aureus
CNS
Aerobic GNBs (pseudo)
Which vaccines are given at birth according to the SA EPI schedule?
BCG
OPV - 0
Which vaccines are given at birth according to the SA EPI schedule?
Which vaccines are given at 6w according to the SA EPI schedule?
Rotavirus - 1
PCV - 1
Hexavalent - 1
Which vaccines are given at 10w according to the SA EPI schedule?
Hexavalent - 2
Which vaccines are given at 14w according to the SA EPI schedule?
Rotavirus - 2
PCV - 2
Hexavalent - 3
Which vaccines are given at 6m according to the SA EPI schedule?
MMR - 1
Which vaccines are given at 9m according to the SA EPI schedule?
PCV - 3
Which vaccines are given at 12m according to the SA EPI schedule?
MMR - 2
Which vaccines are given at 18m according to the SA EPI schedule?
Hexavalent - 4
Which vaccines are given at 6y according to the SA EPI schedule?
TdaP - 1
Which vaccines are given at grade 5 according to the SA EPI schedule?
TdaP (campaign only)
Which vaccines are given at 9y according to the SA EPI schedule?
HPV (campaign only)
Which vaccines are given at 12y according to the SA EPI schedule?
TdaP - 2
At which ages is rotavirus vaccine given?
6w
14w
At which ages is hexavalent vaccine given?
6w
10w
14w
18m
At which ages is PCV vaccine given?
6w
14w
9m
At which ages if MMR given?
6m
12m
What is the most common cause of bacterial meningitis?
S. pneumo
What are the SA PCV vaccines available?
PCV 7 (2009)
PCV 13 (2011)
What is the rate of CTX non-susceptibility for s.pneumo in SA?
8-10%
What are risk factors for mortality with s. pneumo meningitis?
HIV
Smoking
Chronic lung disease
In which age group is haemophilus influenzae most common?
Infants
Low incidence overall
What is the rate of ampicillin non-susceptibility to haemophilus influenza?
8%
In which population does n. meningitides occur?
Healthy, young patients
Highest incidence is in infants
What are risk factors for n. meningitidis meningitis?
Terminal complement deficiency
Lack of MAC formation
What was the usual outbreak season of n. meningitidis?
Dry season in the sub Saharan “meningitis belt”
Which serotype is not included in the n. meningitidis vaccine?
B
What is the rate of penicillin non-susceptibility in n.meningitidis in SA?
55%
2 cipro resistant isolates which has consequences for PEP
What is the difference between early and late neonatal meningitis
Early - <7d
Late - >7d
When is the s. agalactiae conjugate vaccine given in pregnancy?
3rd trimester
What are risk factors for l. monocytogenes meningitis?
Extremes of age
Cell-mediated immunity defects
What is the clinical presentation of l. monocytogenes?
Gastroenteritis
What is the clinical presentation of l. monocytogenes specific to pregnancy?
Malaise
Transient bacteremia
Placentitis
Amnionitis
What is the clinical presentation of l. monocytogenes specific to neonates?
Acute bacterial meningitis
Septicemia
Encephalitis
Which antibiotics is l. monocytogenes intrinsically resistant to?
Cephalosporins (the first line for acute bacterial meningitis)
Ampicillin is the drug of choice
Name other causative organisms of meningitis
Enterovirus
VZV
Mumps
HSV
HIV
Rickettsia
Treponema pallidum
What is the normal CSF WCC?
0-5
What is the normal CSF protein?
0.15-0.45
What is the normal CSF glucose?
2.5 - 3.5 (>60% serum glucose)
What is the normal CSF pressure?
50-150
What are the CSF parameters in bacterial meningitis?
++ WCC
>50% PMN
Protein >1
Glucose <2.2
Pressure increased
What are the CSF parameters in viral meningitis?
++WCC
>50% lymphocytes
Protein normal
Glucose normal
Pressure normal
What are the CSF parameters in fungal meningitis?
+WCC
>50% lymphocytes
Protein normal
Glucose normal/low
Pressure increased
What are the CSF parameters in TB meningitis?
++WCC
>50% lymphocytes
Protein 1-5
Glucose normal/low
Pressure normal/increased
How much CSF must be included for culture?
> 1ml
Which biomarkers have good NPV for bacterial meningitis?
CRP<20 with NBO and normal CSF
When is PCR multiplex assay performed?
If
- viral suspected
- previous antibiotics
- pleocytosis but gram NBO
Which bacteria are included on the BioFire?
E.coli
Haemophilus
L. mono
N. meningitidis
S. agalactiae
S. pneumo
Which viruses are included on the BioFire?
CMV
EV
HSV1+2
HHV-6
HPeV (human parechovirus)
VZV
Which fungi are included on the BioFire>
Crypto neoformans
Crypto gattiii
In which patients should you add ampicillin for?
<1m
>50y
Immunocompromised
In studies in high income countries, meningitis with which organism had decreased hearing loss?
H. influenzae
In studies in high income countries, meningitis with which organism had decreased mortality?
S.pneumo
Which risk factors must you exclude in recurrent meningitis?
Anatomical defects
Asplenia
Immunodeficiency
Which bacterial meningitis organisms are notifiable?
Neisseria
Haemophilus
L. monocytogenes
Which bacterial meningitis organisms require PEP?
Neisseria - single dose cipro
H. influenza - rif daily for 4d
Which HCWs are considered close contacts requiring PEP?
Any exposure to nasopharyngeal secretions
When does an index cause need PEP?
If not treated with 3rd gen cephalosporin (for nasopharyngeal colonisation)
When does an index meningococcal need droplet infection precautions?
Until 24h post treatment initiation with 3rd gen cephalosporin
What antibiotic should you add if the s.pneumo is CTX resistant or non-responsive?
Vancomycin