CNS Viruses Flashcards
neuroinvasive virus?
can enter/infect CNS
What is neurotropic virus?
can replicate in nerve cells
neurovirulent virus?
can cause disease within nervous system
Myelitis is?
infection of spinal cord
encephalomyelitis
brain and spinal cord infected
primary vs. secondary encephalitis?
- primary: direct viral infection
2. secondary: post-infectious via past viral infection
viral vs. bacterial meningitis?
viral less severe but more common
main cause of viral meningitis?
- enteroviruses
2. mumps, varicella zoster, influenza, HIV, HSV1,2
most likely cause of most serious viral encephalitis?
HSV1(face),2 (genital)
Rabies
arboviruses
enteroviruses
post infectious encephalomyelitis? eg.?
inflamm and demyelination, no virus present, autoimmune, Guillan-Barre
Reye’s Syndrome is? who? fatality? when took what med made it worse?
Kids, post infection with influenza/varicella/25% fatality, parents gave aspirin during initial fever
what is a late sequel to measles?
chronic demyelinating disease, takes 30 years
HIV can progress to?
AIDS encephalopathy, 50% develop dementia
How can viruses spread to CNS if there is the BBB?
travels via peripheral axon fibres to CNS
why aren’t viruses killed when they are moving within nerves?
no class 1 molecules for immune system to recognize
Viruses traversing 2 nerves how?
viral progeny can cross synaptic junction
what 3 vessels in the brain can viruses enter via blood stream?
choroid plexus blood vessels
meningeal
cerebral
HSV and coronavirus can enter the brain how?
olfactory bulb
viruses replicate in 2 cells in the brain:
- neurons: direct kill
2. oligodendrocytes
Rabies has to grow in nerve cells?
yes, obligatory
Rabies has envelope? so what?
Yes, budding from infected cells
Rabies hides from immun system?
Nope
Australian ‘Rabies’ is called?
Lyssavirus from bats
Rabies symptoms?
Aggression
thirst/terror drinking water
foaming at mouth
How long does it take rabies to get to CNS? what does that mean?
10-60 days
means you can vaccinate after you get bitten
Alpha herpes viruses are what 3 kinds?
HSV 1
HSV 2
Varicella Zoster
does herpes have to grow in nerves? what kind of DNA? envelope?
Yes
dsDNA
enveloped
primary infection of HSV 1 involves? spread how?
mouth/throat
spread via saliva
What is most common cause of severe sporadic encephalitis?
HSV
Varicella Zoster latent phase hides where?
dorsal root ganglia
Polio: has to grow in nerves? envelope?
Not obligatory nerve growth
no envelope
polio kills it host?
yes, cytocidal
what kind of virus is polio?
enterovirus
what does low neuroinvasiveness mean?
hardly gets into CNS
why does polio cause paralysis?
invades spinal cord anterior horn cells
polio vector?
faecal-oral
what happens if polio paralyzes lungs?
Will die unless they are in iron lung
What other enteriovirus besides polio can cause meningitis? how spread?
Coxsackie B, A, echo viruses
fecal-oral spread
