Micro U3 L3. Flashcards
What is the MC form of meningitis in the US?
viral - usually resolve without treatment
What is the MC cause of viral meningitis? Symptoms?
enterovirus - usually cause no symptoms or illness
What are other causes of viral meningitis besides enterovirus?
HSV, EBV, influenza, mumps, measles, VZV, arboviruses
MCC of bacterial meningitis - who is at greatest risk?
streptococcus pneumoniae - infants under 2 and compromised immune systems
Meningococcal meningitis
MCC of bacterial meningitis in children and young adults, highly contagious, neisseria meningitidis
Which common cause of bacterial meningitis has had a decreased incidence due to vaccination?
haemophilus influenzae type b
What are the MC causes of meningitis in the neonate?
group b strep, escherichia coli, listeria monocytogenes (passed mother to baby)
Chronic meningitis causes
mycobacterium tuberculosis (TB), treponema pallidum (syphilis), fungi
MCC fungal meningitis
crytococcus neoformans (found in dirt and bird droppings) - usually seen in immune-compromised patients
Which form of meningitis is not contagious?
fungal = inhale spores from environment
parasitic meningitis - MC - treatment
rare, lethal = naegleria fowleri (single cell in warm water lakes and rivers) = no antimicrobial agents so frequently fatal
encephalitis causes
HSV, enteroviruses, rabies, arboviruses (bacterial, fungal, parasitic encephalitis are rare)
MC arbovirus encephalitis in the US
West Nile virus
Which encephalitis tends to be the most severe?
EEE (eastern equine encephalitis)
Which encephalitis has a vaccine?
Japanese encephalitis in rural farming areas in Asia
Signs and symptoms of meningitis and encephalitis
fever, headache, stiff neck, sensitivity to light, mental changes, lethargy (encephalitis may also include neurological problems)
Which group is at highest risk for complications?
newborns
How does normal CSF analysis appear?
clear and colorless (like water)
CSF protein
small amount normally present in CSF - increases common with meningitis, brain abscess, neurosyphilis
CSF glucose
normal = 2/3 concentration of blood glucose - decreased when there are abnormal cells metabolizing such as bacteria or WBCs
How does the WBC differential change in a bacterial infection? viral infection? parasitic?
bacterial: increase neutrophils. viral: increase lymphocytes. parasitic: increase eosinophils
What are the follow up tests to abnormal CSF?
detection of viruses with PCR, CSF cryptococcal antigen to detect fungal infection, AFB smear for TB, VDRL for syphilis
CSF lactic acid
increased with bacterial and fungal meningitis
CSF lactate dehydrogenase
used to differentiate between bacterial and viral meningitis
CSF C-reactive protein (CRP)
acute phase reactant and elevated with inflammation - increased with bacterial meningitis
procalcitonin
high blood level is strong indication of bacterial meningitis
What difference in the titer of antibody between two samples collected a month apart indicates a recent infection by a microorganism?
four fold increase
EEG
electroencephalography - detects abnormal brain waves
Which causes of meningitis/encephalitis have vaccines?
haemophilus influenzae type b, streptococus pneumoniae, neisseria meningitidis
Neisseria meningitidis - what can be done for prevention?
meningococcal - vaccine or antibiotics for a few days if they had close respiratory contact with it
Treatment of encephalitis and menigitis
targeted to cause of infection along with bed rest, fluirds, pain relief, anti-inflammatory drugs, anti-seizure medication, sedatives, anti-nausea agents, corticosteroids to reduce tissue and brain swelling
Treatment for bacterial causes of encephalitis/menigitis
broad-spectrum antibiotic - must be able to pass BBB - IV - continued for weeks, months or years - drain infected abscesses or sinuses
