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35 Cards in this Set
- Front
- Back
Signs of Acute Bacterial Meningitis
CSF |
Fever, headache, irritability, stiff neck, convulsions, drowsiness, coma
CSF: gram stain and/or bacteria culture usually positive UNLESS pt treated w/ antibiotics prior to eval |
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Meningitis definition
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inflammation of the meninges of the brain or spinal cord, infection located within the subarachnoid space
CSF Acute, Recurring, and Chronic |
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Encephalitis definition
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inflammation of the brain
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Myelitis definition
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inflammation of the spinal cord
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Brain abscess definition
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focal intrcranial infection in the brain
Develops into a collection of pus surrounded by capsule |
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Subdural empyema definition
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infection between dura mater and arachnoid
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Epidural abscess definition
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localized infection between the dura mater and the overlying skull or vertebral column
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Routes of Infection of the CNS
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Hemtogenous spread with most infectious agents From extracranial foci or by retrograde propagation of infected thrombi within emissary veins
Neurotropic spread in the case of some viruses (herpes simplex and rabies) Spread of organisms through bone Injury - traumatic inoculation of extradural bacteria Surgury - shunts etc congenital problems Otitis - by extension Sinusitis - by extension |
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Haemophilus influenzae ID & route of transmission
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gram -, pleomorphic bacilli
spread via aerosol, some have polysacch capsule, req. factor X (hemin) & V (NAD/NADPH) on choco agar for growth |
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Haemophilus influenzae disease
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meningitis: 1/3 survivors have deafness
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Haemophilus influenzae predisposing factors & menigitis spread
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pharyngitis, otitis media, usually hematogenous spread
Nasopharyngeal carriers = high incidence of meningitis, non-type B |
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Haemophilus influenzae prophylaxis
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Immunize w/ Hib conjugate at 2 months old
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Haemophilus influenzae strains
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type B capsule = disease
nasopharyngeal = common non-B type, (high incid of menigitis) encapsulated = more virulent (non-encapsulated now dominates c/o immu) |
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Common bacterial meningitis species
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H. influenzae > N. meningitidis > S. pneumonia > S. agalactiae > L. monocytogenes > other/unknown
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Streptococcus pneumoniae ID
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Gram + diplococcus, α-hemolytic (green color), Optichin positive, pili
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Streptococcus pneumoniae virulence
& pathogenesis |
antiphagocytic capsule, pili (attachment), cross endothelial via receptor
#1 c/o meningitis in adults complication of bacteremia, pneumonia, mastoiditis, endocarditis, sinusitis, OR head wound |
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#1 c/o meningitis in adults
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Streptococcus pneumoniae
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Neisseria meningitidis ID
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Gram - diplococcus, oxidase positive, Opa (opaque protein - opaque if present)
Ferments glucose & maltose Grow on blood or choco agar (not fastidious) (need Thayer-Martin Selective agar to exclude other species - grows only Neisseria) |
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Neisseria meningitidis transmission
virulence/pathogenicity |
Respiratory transmission - overcrowing (winter/early spring epidemics, military)
Virulence: 1) Antiphagocytic capusle - invasive (13serotypes) 2) pili (mucosal attachment) 3) Opa (downregulated during invasive growth) 4) LOS (coat selves w/ host sialic acid attached to galactose on LOS) |
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Neisseria meningitidis growth
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V-C-N inhibitor: (Vanco, colistin, nystatin) use to grow only N. meningitidis
V-C-N-T: (Same but w/ trimethoprim) for better recovery/growth of Neisseria |
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Listeria monocytogenes
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Gram + motile rod, food borne
death in fetus & maternal in pregnant or immunocompromised |
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Strep agalactiae classification
found where |
GBS, in vagina of some women
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Strep agalactiae disease
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mengitis, pneumonia, sepsis in newborn
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Aerobic Gram - bacilli
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E. coli (esp. K-1) - rod from perineal flor of mother
Klebsiella spp serratia marcescens pseudomonas aeruginosa Salmonella |
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Conditions predisposing to bacterial meningitis
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head trauma, neurosurgery, neonate, elderly, immunocompromised
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Staph causing meningitis
predisposing factors |
Staph aureus
staph epidermidis factors: neurosurgery, CSF shunts, head trauma, sinusitis, pneumonia |
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Chronic meningitis definition
frequency |
Neuro signs/symptoms persist and CSF abnormal for 4 weeks
rarer than acute meningitis |
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Chronic meningitis causes
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m. tuberculosis, brucellosis, syphilis, Lyme disease
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Brain abcess definition
spread |
focal infxn of brain itself
spread from contiguous source (otitis media, mastoiditis, sinusitis, dental, trauma) less commonly from distant site (hematogenous or heart or lung) |
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Brain abcess etiology
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Aerobic/anaerobic/microaerophilic strep
Bacteroides Aerobic cocci (staph aureus) gram - RARE Toxoplasma gondii (esp. in HIV +) |
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Intracranial Epidural abcess definition
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lesion creating space btwn dura mater & skull (must peel dura from skull)
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Intracranial Subdural empyema definition
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infxn btwn dura mater & arachnoid mater
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Etiology/bugs of intracranial abcess/empyema
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staph aureus, anaerobes, gram -, H influenzae (extension of meningitis)
Paranasal sinus source in >50% cases middle ear/mastoid in 10-20% cases can follow truama, surgery, pre-existing subdural hematoma |
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Spinal subdural empyema definition
epidural abcess spread/etiology |
actual space in spine (epidural space) - infxn spread unimpeded
source from osteomyelitis or paravertebral infxn, hematogenous spread |
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Etiology/bugs of spinal abcess/empyema
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staph aureus, anaerobic or anaerobic strep, gram - bacilli
spread from distant source of sepsis |