CNS Infections Flashcards
meningitis should always be treated like __________
an emergency
what is more acute, bacterial or viral meningitis?
bacterial
what is meningitis?
infection/inflammation of meninges
what are the common clinical symptoms of meningitis?
nuchal rigidity
headache
confusion
drowsiness
how is meningitis diagnosed?
lumbar puncture
what are the requirements for collecting a lumbar puncture sample?
4 mL CSF
1st tube goes to chemistry
2nd + 3rd tubes go to micro
why can’t the first LP tube go to micro for meningitis diagnosis?
1st tube is a skin puncture
will just be normal flora
what is the problem with gram stains for meningitis?
poor sensitivity
what are the 2 inflammatory condition of the CNS?
- encephalitis
- meningoencephalitis
what is encephalitis?
inflammation of brain tissue
encephalitis is most often caused by _________ infections
viral
is encephalitis the same as meningitis?
no
what I meningoencephalitis?
inflammation of meninges + brain tissue
what are the 2 ways of acquiring meningitis?
- seeding of meninges
- direct inoculation (trauma, surgery)
how are the meninges “seeded”?
from bloodstream secondary to bacteremia or viremia
why is oral health important for preventing meningitis?
organism from the mouth and oropharynx seed into brain
what happens to the BBB with inflammation?
increased permeability allows for more seeding
who is at highest risk for bacterial meningitis? why?
neonates
immature immune system
how do neonates acquire bacterial meningitis?
birth canal
what are the top 3 organisms that cause bacterial meningitis in neonates?
- GBS
- E. coli
- listeria monocytogenes
how do we prevent GBS and bacterial meningitis in neonates?
screening pregnant women at 35 week
why is bacterial meningitis difficult to diagnose in neonates?
general signs and symptoms are difficult to interpret
how is the baby exposed to listeria monocytogenes?
if mom eats soft cheeses and deli meats –> placenta –> baby
what are the complications of bacterial meningitis in neonates?
blindess
hearing loss
developmental delays
what are the top 3 organisms that cause bacterial meningitis in children? what do these have in common?
- S. pneumoniae
- H. influenzai
- N. meningitides
all colonize RT
S. pneumoniae haș very high colonization in ________________
the respiratory tract
what is the earliest vaccine we give?
H. influenzae
GBS causes _____________ in infants, but not in _____________
causes meningitis, pneumonia and bacteremia
not in adults
what do you do if a non-pregnant woman tests positive for GBS? why?
nothing
normal colonizer of genital tract
what do you do if E. coli is in the GI tract?
nothing if asymptomatic
what do you do if S. pneumonia is found in the respiratory tract?
nothing
what is the reason for N. meningitidis outbreaks?
quadrivalent vaccine only covers 4x strains
doesn’t cover the B strain which causes outbreak
________________ is almost never seen as meningitis
H. influenzae
all 3 causes of bacterial meningitis in children are ___________ preventable
vaccine
what are the top 2 organisms that cause bacterial meningitis in adults?
- S. pneumoniae
- N. meningitidis
what is a less common cause of bacterial meningitis in adults?
listeria monocytogenes
many healthy, non-pregnant woman have vaginal _____________ of ________________
vaginl carriage of GBSS
full term babies that become carriers of GBS can develop ________
meningitis
what babies are at high risk for E. coli meningitis?
preterm
LBW
what type of bacteria is listeria monocytogenes?
gram positive bacillus
what are the 2 ways of transmitting listeria monocytogenes to infants?
- oral ingestion –> intestinal penetration –> circulation
- lateral bacteremia –> transplacental
listeria monocytogenes is incredible rare, except for which populations?
immunocompromised
elderly
why is S. pneumoniae so pathogenic?
capsule helps it evade immune system
where is S. pneumoniae carriage?
nose and throat
where is N. meningitidis carriage?
nose and throat
what is the #1 cause of bacterial meningitis in teens ad adults?
N. meningitidis
what are the 3 vaccines for . meningitidis?
- quadrivalent
- meningococcal group C
- meningococcal group B
how long does it take to grow bacteria for meningitis diagnosis? what should be done in the meantime?
24-24 hours?
broad spectrum antibiotics
what 3 host factors should be assessed in CSF for meningitis?
- glucose
- protein
- WBCs
bacterial meningitis - glucose
low
viral meningitis - glucose
normal
fungal meningitis - glucose
low
bacterial meningitis - protein
high
viral meningitis - protein
low
fungal meningitis - protein
moderate
bacterial meningitis - WBCs
high
viral meningitis - WBCs
moderate
fungal meningitis - WBCs
moderate
how is bacterial meningitis diagnosed?
1 PCR
what causes fungal meningitis?
cryptococcus neoformans
what is cryptococcus neoformans?
yeast with a large capsule
where is cryptococcus neoformans found?
environmental bird poop
cryptococcus neoformans meningiti is more common in what populations?
T cell immunocompromised
- lymphoma
- AIDs
- steroids
if a patient in the ICU is being treated with dexamethasone (steroids) and becomes infected with cryptococcus neoformans, this is an ______________ infection
opportunistic
how is C. neoformans meningitis diagnosed?
culture
latex agglutination
what is latex agglutination?
rapid antigen test
latex beads with specific C. neoformans antibody added to CSF
C. neoformans will bind latex beads
viral meningitis is self-limiting, unless caused by what?
HSV-1
HSV-2
VZV
what is more common, bacterial or viral meningitis?
viral
most cases of viral meningitis are ______________
self limiting
most viral meningitis cases are caused by _______________
enterovirus
