Lecture 22 - Rabies Flashcards
What is one of the oldest known viral diseases?
rabies
What is “rabies” also called?
hydrophobia
What do you know about (-)ssRNA viruses?
brings a polymerase with it so that it can make the mRNA
Why was “rabies” called “hydrophobia” in the 1800s?
people infected have a fear of water and cannot swallow water
What are the cells that rabies like to infect?
neural cells = neurotrophic virus
Which cells do rabies virus replicates in first?
muscle cells
How does the rabies virus get transported to the central nervous system?
attaches to a viral receptor on peripheral nerve cells of the neuromuscular junction
How do humans get exposed to rabies?
by a bite
What is the viral receptor for rabies virus?
nicotinic acetylcholine receptor (nAchR)
Where are nAchR (nicotinic acetylcholine receptors) only found?
post-synaptic muscle membrane not presynaptic nerve membranes
What is the direction of movement within the neuron the rabies virus takes called?
retrograde = goes towards nucleus/cell body
How is the rabies virus taken into the cell?
receptor-mediated endocytosis
Why might it take a while before symptoms start to show for a rabies infection?
it needs to travel through the axons to the cell body to the CNS
Why could rabies virus genome immediately make transcripts?
because it brought its enzyme RdRp with it
How does the virus get out of neuronal cells into the salivary secretions of animals?
the rabies virus eventually re-infects peripheral nervous system and makes its way to other organs such as saliva
What can be done once a person infected with the rabies virus shows symptoms of the disease?
nothing anyone can do
After the rabies virus affects the CNS of an infected person, what does this cause?
delirium, hydrophobia, aggression, stupor, hypersalivation/drooling, spasms,
What is post-exposure prophylaxis (PEP)
used when one becomes exposed = they are treated for rabies
How does rabies virus enter the body through?
wound in skin or mucosal surfaces
How far has the rabies virus spread once the clinical symptoms have appeared?
widely spread throughout CNS and other organs
Which type of neurons do rabies virus replicate in before moving into CNS?
motor neurons
How does rabies cause neural dysfunction?
mediated by inhibition of neurotransmitters or neuronal hyperexcitability
Do rabies virus damage the brain?
no
What is the PEP (post-exposure prophylaxis) method used against rabies virus?
immunoglobulin | antibodies from vaccinated blood donors = provides passive immunity until active antibodies are produced from vaccine
