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