infectious dz Flashcards
How are patients with bacterial meningitis initially treated
Start appropriate empiric antibiotic therapy urgently (within 60minutes of arrival to the ER) after patient’s arrival at the hospital
Bacterial meningitus classic triad
Only ~45% of patients have the complete classic triad of fever,decreased conciousness and neck stiffness (nuchal rigidity/meningismus) but nearly 100% of patients have at least 2 of 4 symptoms (fever, headache, nuchal rigidity, altered mental status).
Bacterial meningitis findings other than triad
seizures, nausea/vomiting, myalgias, cranial nerve palsies (III, VI, VII, VIII) and focal deficits (hemiparesis, ataxia, gaze preference), papilloedema in <1% cases
Median age of patients with bact meningitis
42 yrs- use to be 1yr but Hib vaccine has eliminated meningitis in children mostly
bacterial meningitis pathogenesis
A. Bacteria can reach the subarachnoid space from: (1) the bloodstream (most common) (2) adjacent intracranial infection (sinusitis, mastoiditis, otitis) (3) congenital, traumatic or surgical defects in skull/spinal column.
B. Bacterial meningitis is a disease of the subarachnoid space. Bacterial cell wall components stimulate pro-inflammatory cytokines (e.g. TNF, IL-1), increase BBB permeability, and recruit neutrophils (PMNs). PMNs add to purulent exudates, and enhance cytotoxic edema via reactive oxygen species. Hydrocephalus and infarction from vasculitis can occurA. Bacteria can reach the subarachnoid space from: (1) the bloodstream (most common) (2) adjacent intracranial infection (sinusitis, mastoiditis, otitis) (3) congenital, traumatic or surgical defects in skull/spinal column.
B. Bacterial meningitis is a disease of the subarachnoid space. Bacterial cell wall components stimulate pro-inflammatory cytokines (e.g. TNF, IL-1), increase BBB permeability, and recruit neutrophils (PMNs). PMNs add to purulent exudates, and enhance cytotoxic edema via reactive oxygen species. Hydrocephalus and infarction from vasculitis can occurA. Bacteria can reach the subarachnoid space from: (1) the bloodstream (most common) (2) adjacent intracranial infection (sinusitis, mastoiditis, otitis) (3) congenital, traumatic or surgical defects in skull/spinal column.
B. Bacterial meningitis is a disease of the subarachnoid space. Bacterial cell wall components stimulate pro-inflammatory cytokines (e.g. TNF, IL-1), increase BBB permeability, and recruit neutrophils (PMNs). PMNs add to purulent exudates, and enhance cytotoxic edema via reactive oxygen species. Hydrocephalus and infarction from vasculitis can occur
Most common organisms causing meningitis in Pt <2 months
*Streptococcus agalactiae (Group B Strep)
*Gram-Negative Rods (e coli)
Listeria monocytogenes
Streptococcus pneumoniae (pneumococcus)
Hemophilus influenzae (H flu)
(0-5%) Neisseria meningitidis (meningococcus)
(0-1%) Staphylococcus speciesStreptococcus agalactiae (Group B Strep)
*Gram-Negative Rods (e coli)
Listeria monocytogenes
Streptococcus pneumoniae (pneumococcus)
Hemophilus influenzae (H flu)
(0-5%) Neisseria meningitidis (meningococcus)
(0-1%) Staphylococcus speciesStreptococcus agalactiae (Group B Strep)
*Gram-Negative Rods (e coli)
*Listeria monocytogenes
Streptococcus pneumoniae (pneumococcus)
Hemophilus influenzae (H flu)
(0-5%) Neisseria meningitidis (meningococcus)
(0-1%) Staphylococcus species
Most common organisms causing meningitis in Pt 2-23months
(50%) Streptococcus pneumoniae (pneumococcus)
(10-15%) Neisseria meningitides (meningococcus)
(10-15%) Streptococcus agalactiae (Group B Strep) E coli
(5-10%) Haemophilus influenzae (nontypable H. flu)
(1-2%)Listeria monocytogenes
(0-5%) Staphylococcus species
(50%) Streptococcus pneumoniae (pneumococcus)
(10-15%) Neisseria meningitides (meningococcus)
(10-15%) Streptococcus agalactiae (Group B Strep) E coli
(5-10%) Haemophilus influenzae (nontypable H. flu)
(1-2%)Listeria monocytogenes
(0-5%) Staphylococcus species
(50%) Streptococcus pneumoniae (pneumococcus)
(10-15%) Neisseria meningitides (meningococcus)
(10-15%) Streptococcus agalactiae (Group B Strep) E coli
(5-10%) Haemophilus influenzae (nontypable H. flu)
(1-2%)Listeria monocytogenes
(0-5%) Staphylococcus species
Most common organisms causing meningitis in Pt 23 monts -34 yrs
(~40%) Neisseria meningitidis (meningococcus)
(~40%) Streptococcus pneumoniae (pneumococcus)
(5-10%) Hemophilus influenzae (H flu)
(<5%)Streptococcus agalactiae (Group B Strep)
(1-2%)Listeria monocytogenes
(1-2%) Staphylococcus species
(1-2%) Gram- Negative Rods
Most common organisms causing meningitis in Pt >35 yrs
(50-70%) Streptococcus pneumoniae (pneumococcus)
(10-25%) Neisseria meningitidis (meningococcus)
(1-10%) Hemophilus influenzae (H flu)
(5-10%)Listeria monocytogenes (25% of cases in age > 60yrs or immune compromise)
(1-10%) Staphylococcus species (more common w/ neurosurg, head trauma, shunts)
(1-10%) Gram- Negative Rods (more common as a nosocomial infection)
( 60yrs or immune compromise)
(1-10%) Staphylococcus species (more common w/ neurosurg, head trauma, shunts)
(1-10%) Gram- Negative Rods (more common as a nosocomial infection)
( 60yrs or immune compromise)
(1-10%) Staphylococcus species (more common w/ neurosurg, head trauma, shunts)
(1-10%) Gram- Negative Rods (more common as a nosocomial infection)
(<5%)Streptococcus agalactiae (Group B Strep)
Diagnostic tests for suspected meningitis
Complete LP immediately (no delay for neuroimaging) in all patients with suspected meningitis unless:
- decreased level of consciousness 2. focal neurologic deficits 3. papilloedema 4. new onset seizures 5. History of CNS disease or an associated condition (e.g. frontal sinusitis) that increases probability of brain abscess/ empyema. 6. Immunocompromised. If any of the above, get blood cultures and immediate empiric antibiotics while doing CT/MRI, prior to LPComplete LP immediately (no delay for neuroimaging) in all patients with suspected meningitis unless:
- decreased level of consciousness 2. focal neurologic deficits 3. papilloedema 4. new onset seizures 5. History of CNS disease or an associated condition (e.g. frontal sinusitis) that increases probability of brain abscess/ empyema. 6. Immunocompromised. If any of the above, get blood cultures and immediate empiric antibiotics while doing CT/MRI, prior to LPComplete LP immediately (no delay for neuroimaging) in all patients with suspected meningitis unless:
- decreased level of consciousness 2. focal neurologic deficits 3. papilloedema 4. new onset seizures 5. History of CNS disease or an associated condition (e.g. frontal sinusitis) that increases probability of brain abscess/ empyema. 6. Immunocompromised. If any of the above, get blood cultures and immediate empiric antibiotics while doing CT/MRI, prior to LP
Normal CSF profile of adults and newborns
Adult: WBC (predominately lymphs and monos) <150mg/dL, glucose 2/3 of serum glucose (variable)
Bacterial meningitis CSF profile (WBC, cell type, glucose, protein, useful test
WBC: 100-10,000. Cell type: PMNs (80-95%). Glucose: low (50mg/dl). Gram stain
Viral meningitis CSF profile (WBC, cell type, glucose, protein, useful tests
WBC: 10-2,000. cell type: mononuclear lymps. Glucose: normal. Protein: normal or slightly elevated. PCR
Viral encephalitis CSF profile (WBC, cell type, glucose, protein, useful tests
WBC: 10-2,000. cell type: mononuclear lymps. Glucose: normal. Protein: elevated. PCR, MRI
How are neonates/ infants (<1-3mos) treated for bacterial meningitis
Ampicillin and Cefotaxime or ampicillin and aminoglycoside