Bacterial Meningitis part 1 Flashcards
define bacterial meningitis
inflammation of meninges surrounding the brain and spinal cord due to bacterial invasion to the CNS
what is ESSENTIAL to ensure beneficial outcomes for bacterial meningitis
prompt recognition and early treatment
survivors of bacterial meningitis may experience one or more…..
neurologic disabilities (seizures)
3 ways in which bacteria can get into the CNS and cause bacterial meningitis
-hematogenous spread (thru blood - most common)
-contiguous spread (from sinusitis or otitis media – spreads to CNS)
-direct inoculation (head trauma or neurosurgery)
in one word, what is the clinical presentation of bacterial meningitis
ABRUPT
name the 3 things in the “classic triad” for the clinical presentation of bacterial meningitis
fever
nuchal (neck) rigidity
altered mental status
clinical presentation of bacterial meningitis specifically in infants
bulging fontanelle - skull not fully developed yet
2 physical assessments that can be used to diagnose bacterial meningitis
Kernig’s sign – lifting leg
brudzinski’s neck sign – cant bring their head up while laying down without bending their knees bc of the inflammation
what procedure can be done to get a CSF analysis to diagnose bacterial meningitis
a lumbar puncture
what will be the “appearance” and “opening pressure” of a CSF culture with bacterial meningitis
appearance will be purulent and cloudy (should be clear)
opening pressure will be elevated from normal
what will the WBC count be in cells/mm cubed in a CSF culture infected with bacterial meningitis
greater than 500 cells/mm cubed
in a CBC with differential, which WBC will be very elevated in a CSF sample affected by bacterial meningitis
NEUTROPHILS
how will the protein and glucose levels be in a CSF sample infected by bacterial meningitis
protein will be ELEVATED and glucose will be LOW (bc so many WBC being produced and bacteria itself all eat the glucose for food)
in a CSF sample infected with bacterial meningitis, how will the CSF: blood glucose ratio be
DECREASED
aside from bacterial, what other meningitis can a person have
fungal or viral meningitis
in lab tests, a sample of CSF infected with bacterial meningitis will have leukocytosis with ______ shift
left
in SEVERE cases of bacterial meningitis, what will happen to WBC count
will have leukopenia (decreased WBC)
which 2 cultures are done in a suspected case of bacterial meningitis??
when are antibiotics given in relation to these cultures?
CSF and blood cultures
must do these cultures BEFORE starting antibiotics
will platelet count be affected by bacterial meningitis
YES will have thrombocytopenia (dec platelet count)
MOST bacterial meningitis cases are caused by which pathogen?
name 4 others
most - streptococcus pneumoniae
0thers - group b strep (agalactiae)
neisseria meningitidis
h. influenzae
listeria monocytogenes
others - gram negative organisms and staph
streptococcus pneumonia is the leading cause of bacterial meningitis in _______ of age
greater then 2 months
streptococcal meningitis typically occurs how
results as a secondary infection from a primary infection like ear or sinus infections
ie - strep pneumo goes from ear to the CNS to cause bacterial meningitis
what are some predisposing factors to STREPTOCOCCAL MENINGITIS
pneumonia, endocarditis, CSF leak bc of head trauma, splenectomy, alcohol, sickle cell disease, bone marrow transplant
what is the worldwide leading cause of NEONATAL meningitis
group B strep meningitis
bc of GI and genitourinary colonization in pregnant women, commonly by streptococcus agalactiae (25%0
the term for a pregnant mother causing group b strep meningitis in her neonate is called….
vertical transmission
what may be done to decrease the incidence of group B strep meningitis
universal prenatal screening
intrapartum (during birth) – give prophylactic group B strep antibiotics
what is the leading cause of bacterial meningitis, PARTICULARLY in children and young adults??
what is the bacteria responsible?
MENINGOCOCCAL MENINGITIS
caused by neisseria meningitidis
what are the 5 primarily responsible serogroups of meningococcal meningitis
A, B, C, Y, W,-15
Name some predisposing factors to MENINGOCOCCAL meningitis
smoking
HIV
asplenia
complement deficiency
how is meningococcal meningitis easily distinctable from the others
the presence of a PETECHIA RASH
how is meningococcal meningitis spread
its VERY CONTAGIOUS
can be spread person-person contact from respiratory droplets and pharyngeal secretions
CLOSE CONTACTS INCREASED RISK OF GETTING — NEED TO TAKE CHEMOPROPHYLAXIS TO PREVENT
Which type of meningitis used to be the most common cause of bacterial meningitis in 6months-3years but has declined bc of vaccination?
haemophilus influenza type B meningitis
haemophilus influenzae type b meningitis is associated with what 3 other conditions
middle ear infection
paranasal sinus infection
CSF leakage
listeria monocytogenes is gram (+) or (-)???
what shape???
gram positive rod
listeria monocytogenes primarily affects which populations??
how is it transmitted?
neonates, alcoholics, immunocompromised (inc pregnant), and elderly 50 and up
transmitted by colonization of the GI tract - FOODBORNE ILLNESS
can be caused by soft cheeses and unpasteurized raw produce, coleslaw, ready to eat foods, raw beef and poulty
name some characteristics of gram negative meningitis
UNCOMMON - but increasingly its a cause of bacterial meningitis in NOSOCOMIAL SETTINGS
what are the 2 most common gram negative organisms responsible for bacterial meningitis in adults? what about neonates?
adults - e. coli and pseduomonas
neonates - e. coli and klebsiella pneumoniae
what is the most important independent factor associated with higher risk of gram (-) meningitis in adults?
URINARY TRACT INFECTION
3 main likely organisms to cause bacterial meningitis in NEONATES (less than 1 month)
group b strep
enteric gram (-) - like e. coli
listeria monocytogenes
4 most likely pathogens to cause bacterial meningitis in infants and children (1 month-23 months)
step pneumoniae
neisseria meningitidis
h. influenzae
group B strep (still some but not as many as neonates)
2 pathogens most likely to cause bacterial meningitis in children and adults (2-50 yrs)
nesseria meningitidis
streptococcus pneumoniae
4 pathogens most likely to cause bacterial meningitis in adults greater than 50
listeria monocytogens
streptococcus pneumonia
neisseria meningitidis
enteric gram negatives (bc of hospital exposure)
when CSF and blood cultures are sent to be tested for suspected bacterial meningitis, empiric antibiotics are started based on what?????
AGE – most likely organisms to affect based on age
aside from age, there is also a chart for most likely pathogens based on CONDITION
name the 3 conditions
closed head trauma
penetrating trauma or post neurosurgery
CSF shunt
in penetrating trauma or post neurosurgery, name 5 organisms we would want to cover empirically
NOSOCOMIAL—
pseudomonas
gram negative bacilli (e. coli and klebsiella)
staph epi
staph aureus
in CSF shunt, name 4 organisms we would want to cover empirically
staph epi
staph aureus
gram negative bacilli
p. acnes
in closed head trauma, name 3 organisms we would want to cover empirically
step pneumoniae
h. influenzae
group A beta-hemolytic streptococci
*in children <28 days of age and adults >50 years, empiric coverage of what pathogen is recommended
listeria monocytogenes!!
