Lecture 22 - Rabies

Question 1

What is one of the oldest known viral diseases?

Answer 1

rabies

Question 2

What is “rabies” also called?

Answer 2

hydrophobia

Question 3

What do you know about (-)ssRNA viruses?

Answer 3

brings a polymerase with it so that it can make the mRNA

Question 4

Why was “rabies” called “hydrophobia” in the 1800s?

Answer 4

people infected have a fear of water and cannot swallow water

Question 5

What are the cells that rabies like to infect?

Answer 5

neural cells = neurotrophic virus

Question 6

Which cells do rabies virus replicates in first?

Answer 6

muscle cells

Question 7

How does the rabies virus get transported to the central nervous system?

Answer 7

attaches to a viral receptor on peripheral nerve cells of the neuromuscular junction

Question 8

How do humans get exposed to rabies?

Answer 8

by a bite

Question 9

What is the viral receptor for rabies virus?

Answer 9

nicotinic acetylcholine receptor (nAchR)

Question 10

Where are nAchR (nicotinic acetylcholine receptors) only found?

Answer 10

post-synaptic muscle membrane not presynaptic nerve membranes

Question 11

What is the direction of movement within the neuron the rabies virus takes called?

Answer 11

retrograde = goes towards nucleus/cell body

Question 12

How is the rabies virus taken into the cell?

Answer 12

receptor-mediated endocytosis

Question 13

Why might it take a while before symptoms start to show for a rabies infection?

Answer 13

it needs to travel through the axons to the cell body to the CNS

Question 14

Why could rabies virus genome immediately make transcripts?

Answer 14

because it brought its enzyme RdRp with it

Question 15

How does the virus get out of neuronal cells into the salivary secretions of animals?

Answer 15

the rabies virus eventually re-infects peripheral nervous system and makes its way to other organs such as saliva

Question 16

What can be done once a person infected with the rabies virus shows symptoms of the disease?

Answer 16

nothing anyone can do

Question 17

After the rabies virus affects the CNS of an infected person, what does this cause?

Answer 17

delirium, hydrophobia, aggression, stupor, hypersalivation/drooling, spasms,

Question 18

What is post-exposure prophylaxis (PEP)

Answer 18

used when one becomes exposed = they are treated for rabies

Question 19

How does rabies virus enter the body through?

Answer 19

wound in skin or mucosal surfaces

Question 20

How far has the rabies virus spread once the clinical symptoms have appeared?

Answer 20

widely spread throughout CNS and other organs

Question 21

Which type of neurons do rabies virus replicate in before moving into CNS?

Answer 21

motor neurons

Question 22

How does rabies cause neural dysfunction?

Answer 22

mediated by inhibition of neurotransmitters or neuronal hyperexcitability

Question 23

Do rabies virus damage the brain?

Answer 23

no

Question 24

What is the PEP (post-exposure prophylaxis) method used against rabies virus?

Answer 24

immunoglobulin | antibodies from vaccinated blood donors = provides passive immunity until active antibodies are produced from vaccine

Question 25

What is the Milwaukee Protocol for rabies treatment?

Answer 25

inducing a coma to quiet all of the sensations to give the immune system time to ramp up and fight virus

Question 26

What type of treatment is used for rabies?

Answer 26

supportive care, no cure, only preventive measures