Bacterial Infections of the CNS I (meningitis/encephalitis) Flashcards
Nearly 100% of patients with meningitis will present with two of these four symptoms
fever, headache, stiff neck (nuchal rigidity), and altered mental status
Approximately half of all patients with meningitis present with
Fever, Headache, and Stiff Neck
Labs for Dx of Meningitis
gram stain of CSF, cultures, latex agglutination
Bacterial meningitis or Viral Meningitis/encephalitis? presence of PMNs
bacterial
Bacterial meningitis or Viral Meningitis/encephalitis? presence of mono/lymphos
viral
Bacterial meningitis or Viral Meningitis/encephalitis? rare PMNs
Viral
Bacterial meningitis or Viral Meningitis/encephalitis? increased protein
bacterial
Bacterial meningitis or Viral Meningitis/encephalitis? decreased glucose
bacterial
Bacterial meningitis or Viral Meningitis/encephalitis? normal glucose
viral
Bacterial meningitis or Viral Meningitis/encephalitis? increased pressure
bacterial
Bacterial meningitis or Viral Meningitis/encephalitis? normal or slightly increased protein and pressure
viral
Tx: bacterial meningitis
empirical antibiotic therapy (specific after organism identified)
majority of bacterial meningitis cases occur in
infants and children
common agents of bacterial meningitis
S. pneumoniae (50%), N. meningitides (25%) Group B Strep, Listeria monocytogenes, Haemophilus influenzae
Group B strep meningitis is common in
the very young and the very old
incubation of 3-4 days with abrupt onset of fever, hypotension and rash, headache, neck stiffness
meningococcal disease
gram + coccus catalase -, frequently grows in chains (liquid culture), oval cells, polysaccharide capsule
Streptococcus pneumoniae
round mucoid colonies on blood agar, alpha-hemolytic
Streptococcus pneumoniae
susceptible to optochin, susceptible to bile
Streptococcus pneumoniae
most common cause of vaccine-preventable death in the US
pneumococcal disease-causes bacterial meningitis among infants and and young children