Bacterial Meningitis Flashcards
(48 cards)
What is the most common causitive agent of bacterial meningitis? What is the most common cause of neonatal meningitis?
strep pneumo; strep agalactiae
What are the most common causes of community acquired meningitis?
s. pneumo, h. flu, n. meningitidis
What are the most common causes of hospital acquired meningitis?
gram negative rods, s. aureus, other strep or staph
What causes a sudden neck or head pain in meningitis? What is it followed by?
Huge release of inflammatory cytokines, followed by WBC diapedesis into the CSF
What are the three pathways for gaining access to the CNS for meningitis?
Invasion of blood stream and seeding of the CNS (most common), retrograde neuronal pathway (Naegleria), direct contiguous spread (infections, congenital malformations, etc)
What does WBC diapedesis into the brain lead to?
Increased permeability of BBB, increased ICP and edema, eventual decrease in BF to the brain
What is the classic triad of meningitis sx?
Fever, headache, neck stiffness! Also sleepiness, confusion, delirium
What will you find in a hx of meningitis pt?
Exposure to patients with similar illness!!!!! (onset, setting)
A 4 month old infant presents with a bulging fontanelle, a high pitched cry that disappates when he is left alone (paradoxic irritability), and hypotonia. What is at the top of your differential?
Bacterial meningitis!!!
What are some generalized tests to be used to diagnose meningitis?
CBC, serum electrolytes, SERUM GLUCOSE COMPARED WITH CSF GLUCOSE, liver profile
What additional tests can you order to check for meningitis?
Lumbar puncture, cultures, neuroimaging
What is the treatment for meningitis (general)?
empiric abx therapy, steroid (dexamethasone) for swelling, intrathecal abx for hospital acquired
What would you call an intense acute congestion of meningeal blood vessels and purulent exudate?
Purulent meningitis
What are maternal predisposing factors for neonatal meningitis?
premature rupture of membranes, urogenital infection during LATE term, intrauterine infection during EARLY term
What are neonatal predisposing factors for neonatal meningitis?
Immaturity of host defense and immaturity of organ systems (low birth weight)
What are signs and symptoms of neonatal meningitis?
Hyperthermia (usual) or hypothermia (dysregulation in general)
CNS manifestations (lethargy, irritability, seizures)
GI disturbance
Respiratory abnormalities
What are the predominant agents of neonatal meningitis?
Streptococcus agalactiae (group B strep)
E. Coli
Listeria monocytogenes
What are the CDC recommendations to prevent neonatal meningitis?
Universal prenatal screening for vaginal or rectal group B strep for all PGN women 35-37 weeks
What is the exception to routine antibiotic prophylaxis for group B strep positive women at the end of term?
undergoing planned C-section AND who have not begun labor or had rupture of membranes
What is the prognosis for neonatal meningitis?
Generally poor, survivors have permanent defects
You are looking at a gram positive coccus with a gray-white colony and a narrow zone of B-hemolysis. What is it?
Strep Agalactiae
What are the four virulence factors found in strep agalactiae?
capsular polysaccharide
hyaluronidase
collagenase
hemolysin
A 15-day old neonate presents with GBS. What are some clinical manifestations and what is his prognosis?
bone/joint infections, bacteremia (left shift), and meningitis
Where should you obtain a culture for GBS from?
A normally sterile site (blood, CSF, areas with mixed flora)
