Intro To Meningitis Flashcards
What are the three main symptoms with meningitis?
Fever
Headache
Stiff neck (30% of cases)
Can get nausea
Vomiting
Where does meningitis develop?
Subarachnoid space
How do you tell a TB meningitis?
More lymphocytes
What is aseptic meningitis?
Sterile
Misnomer
Viral meningitis
Less likely to see neck sore
when do you see aseptic meningitis?
First year of life
What is the most common viral cause of meningitis?
Enterovirus (RNA virus)
Coxaky, echo
More common in fall
What are characteristics of enterovirus/picornavirus?
Summer and fall Pico for "small" and "RNA" Transmitted orally or fecally (+) sense RNA Icosahedral capsid No envelope
What type of symptoms are associated with septic meningitis?
Acute
Neurological function
What are some treatment for septic meningitis?
Vancomycin (MRSA)
Acyclovir (HSV-2)
Cefepine (pseudomonas)
Ampicillin (listeria)
What are the big three bacterial meningitis organisms?
Streptococcus pneumonia
Neisseria meningiditis
Hemophilus influenza type b
What etiology for septic meningitis is most common in adults?
Streptococcus pneumonia (75%)
What etiology is most common is 11-17 year olds?
Neisseria meningitiditis
What is the vaccine recommended for all adults over 65 for septic meningitis?
13 valent pneumococcal conjugate vaccine
What is the development of meningitis by the 3 most common bacteria?
- Mucosal colonization at nasopharynx
- Invasion and multiplication on bloodstream
3,4. Cross BBB into CSF - Release of inflammatory cytokines in CSF by Microglia and astrocytes
- Subsequent increased permeability of the BBB
- Diapedesis of leukocytes into CSF
- Edema and increased intracranial pressure
- Neuronal injury including hearing loss (CN VIII)
What virulence factors are common in all three major bacteria for septic meningitis?
Capsule
IgA protease
What are the major virulence factors for Neisseria Meningitiditis?
Capsule IgA protease Pili (attachment to mucosa) Endotoxin (gram neg) Outer membrane proteins (gram neg) (Gram negative bacteria)
What are the major virulence factors for Haemophilus influenza?
Capsule IgA protease Pili Endotoxin Outer membrane proteins (Gram neg)
What are the virulence factors for streptococcus pneumonia?
Capsule
IgA protease
(Gram positive bacteria)
What is the Endotoxin form gram negative bacteria?
LPS
What is the Endotoxin in Neisseria meningiditides?
LOS lipooligosaccharide
Why are endotoxins illusive?
They mimic brain sphingolipids
What is LPS mode of action?
Activate macrophages leading to release of NO
And IL-1 (fever) and can activate coagulation leading to purpuric skin
Therefore if you have rash you should be thinking less of strep
What does interleukin 1 do?
Fever
What is the capsule of meningitis bacteria composed of?
Acidic polysaccharides which prevents phagocytosis by PMN Granulocytes