Infectious Disease Flashcards
What organism most often causes bacterial meningitis in infants 0-23 months old?
group B strep
What organism most often causes bacterial meningitis in those 2yo-35yo?
Neisseria
What organism most often causes bacterial meningitis in those 35+ years old?
Strep. pneumo
Group B strep most often causes bacterial meningitis in what age group?
infants 0-23 mos old
Neisseria most often causes bacterial meningitis in what age group?
2yo-35yo
Strep. pneumo. most often causes bacterial meningitis in what age group?
35yo+
What is the pathophys of a bacterial meningitis infection?
sub-arachnoid space is infiltrated by organisms via blood infection or adjacent cranial infection (in kids)
also caused by skull/spinal defects
What is the classic triad of bacterial meningitis?
altered mental status/confusion
fever
nuchal rigidity (stiff neck)
What are other s/s of bacterial meningitis, other than the classic triad of altered mental status/confusion, fever, and nuchal rigidity (stiff neck)?
HA hydrocephalus sz cranial nerve palsies (3, 6, 7, and esp 8) focal defects papilloedema positive Kernig's sign positive Brudzinski's sign
Dx? altered mental status/confusion fever nuchal rigidity (stiff neck) HA hydrocephalus sz cranial nerve palsies (3, 6, 7, and esp 8) focal defects papilloedema positive Kernig's sign positive Brudzinski's sign
bacterial meningitis
What is the tx for bacterial meningitis?
STAT start of empiric Abx, corticosteroids
What tests should be done for suspected bacterial meningitis? What are the results that point towards dx?
blood cultures (positive) lumbar puncture (+ CSF pleocytosis, increased protein, decreased glucose) neuroimaging
When is lumbar puncture contraindicated?
with suspected focal/neuro defects (AMS)
increased ICP
CNS infection or lesion
immunocompromised pts
What are some complications of bacterial meningitis?
meningoencephalitis cranial nerve palsies empyema sz's hydrocephalus new infarcts deafness
What is encephalitis?
inflammation of parenchymal gray matter in the brain
What is inflammation of parenchymal gray matter in the brain?
encephalitis
What are the most common causative agents of viral meningitis (in order)?
enteroviruses (coxsackie, echo)
arboviruses (WNV)
herpes viruses (HSV-2, VZV)
others (HIV, measles/mumps)
What are the most common causative agents of encephalitis (in order)?
arboviruses (WNV)
herpes viruses (HSV-1, CMV, EBV)
others (HIV, flu, Rabies)
What is the pathophys of a herpes-caused viral meningitis or encephalitis?
retrograde movement to the brain –> temporal lobe necrosis
What is the pathophys of West Nile Virus-caused viral meningitis or encephalitis?
mosquito bite causes viral replication in the skin –> dendritic cells take up and move to lymph nodes –> enter blood stream –> travel to spleen –> systemic viral load enters brain
What are the s/s of enterovirus?
rash pharyngitis/herpangia GI complaints pleurodynia myocarditis pericarditis conjunctivitis macular rash
What are the s/s of encephalitis?
fever AMS HA personality changes sz's
Dx? fever AMS HA personality changes sz's
encephalitis
Dx? rash pharyngitis/herpangia GI complaints pleurodynia myocarditis pericarditis conjunctivitis macular rash
viral meningitis (enterovirus infection)
What is the tx for viral meningitis?
acyclovir
What tests and their results are diagnostic for West Nile Virus?
lumbar puncture = positive pleocytosis, increased protein, normal glucose
PCR = positive
serology = positive IgM
Dx?
lumbar puncture = positive pleocytosis, increased protein, normal glucose
PCR = positive
serology = positive IgM
West Nile Virus
