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Flashcards in Encephalitis Viruses Deck (13):

most aggressive/deadly of mosquito-borne encephalitis virus


5% of people get encephalitis; causes mortalilty and permanent disabilities


replication of rabies virus

glycoprotein attaches to receptors on target cell

enters/starts transcribing

when nucleoprotein accumulates, virus switches to replication

coats itself and bounces


pathogenesis of rabies

Enters muscle cells; replicates slowly here
Eventually works its way up motor neuron via retrograde axonal transport
Replicates/spreads through CNS - NEGRI BODIES
Disseminates via peripheral nerves ALL OVA DA BODY(saliva, skin, etc)


prognosis for la crosse virus

mortalitly is rare

most people recover w/few sequelae


pathogenesis of west nile virus

  1. mosquito bite
  2. DC take up virus
  3. viremia(symptoms)
  4. CNS penetration, neuro invasion
    • higher rates in immunocompromised AND CCR5delta32 mutants


in general, what are the number of cases seen each year for each mosquito-borne encephalitis in the US?

west nile >1000

st. louis ~100

EEV/WEEV ~5 each

La Crosse ~100


clinical manifestation of rabies

  1. prodrom/early: flu; parasthesia
  2. acute neuro disease: encephalopathic(bizarre behavior) OR paralytic(ascending paralysis)
  3. DEATH


mosquito-borne encephalitis viruses

west nile, st. louis (flavi)

EEV, WEEV (toga)

la crosse (buny)


treatment for rabies in the "window of opportunity"/before CNS

  1. clean wound well
  2. rabies immune globulin
  3. Vaccine(multiple Im doses in deltoid); LIVE ATTENUATED


la crosse virus is most commonly seen in what area of US

upper mid-west, but spreading to central atlantic


la crosse virus structure

enveloped, helical, ssRNA(-)


EEEV cases in US are from what areas?

WEEV cases in US are from what areas?

EEEV - swamps/summer time

WEEV - western/central states


unique aspect of structural protein transcription in EEEV, WEEV

even though thes are ssRNA(+), structural proteins are made through a RNA(-) intermediate