Viral Pathogenesis

Question 1

what is the process by which a viral infection leads to disease

Answer 1

viral pathogenesis

Question 2

true or false:
majority of viral infections are subclinical

Answer 2

true

Question 3

what does the consequences of viral infections depend on

Answer 3

interplay between a number of viral, host and environmental factors

Question 4

define viral virulence

Answer 4

its relative level of harm compared to another closely related virus

Question 5

true or false:
it is fair to compare virulence between two viruses in different families

Answer 5

false

Question 6

what are some host factors that affect viral pathogenesis

Answer 6

immune statue
genetic background
age
nutrition status
hormonal status

Question 7

true or false:
signs of a viral infection are specific and telling

Answer 7

false - most of them are quite non-specific

Question 8

what are the different courses of infection

Answer 8

acute
latent chronic

Question 9

what are some possible outcomes after an acute infection

Answer 9

recovery with no side effects
recovery with residual effects
death
chronic infection

Question 10

what occurs during a chronic/latent infection

Answer 10

silent subclinical infection for life
a long silent period before disease
reactivation to cause acute disease
chronic relapses
cancers

Question 11

describe the clinical signs, viral shedding and viral detection in tissues for an acute disease

Answer 11

clinical signs - short
virus demonstrable in tissues - short, during the whole disease
viral shedding - during episode of illness

Question 12

true or false:
there is constant shedding of the virus with a latent infection

Answer 12

false
there is only shedding during times when the virus is demonstrable in tissues and episodes of illness

Question 13

when is there shedding of a virus in a chronic disease

Answer 13

continuously

Question 14

where does primary replication of a virus occur

Answer 14

where the virus gains initial entry into the host

Question 15

what is the result of primary replication

Answer 15

low amount of virus being produced – this is due to the entry site

Question 16

define systemic spread of a virus

Answer 16

when the virus uses the bloodstream or CNS peripheral nerves

Question 17

what is the term used when the virus is in the bloodstream

Answer 17

viremia

Question 18

which phase of viremia is when the virus first enters the blood stream for dissemination after entry

Answer 18

primary viremia

Question 19

what is characteristic of primary viremia

Answer 19

low titers of virus

Question 20

which phase of viremia has higher viral titer

Answer 20

secondary viremia

Question 21

which phase of viremia is important for transmission through arboviruses and invasion of the CNS

Answer 21

secondary viremia

Question 22

if the virus is unable to spread through the bloodstream, what other type of spread is there

Answer 22

neural spread

Question 23

what takes place at target organs/tissues following systemic spread where viruses replicate at higher titers

Answer 23

secondary replication

Question 24

what dictates the preference of a virus to replicate in a certain type of cell

Answer 24

Tropism

Question 25

what is tropism for viruses

Answer 25

viral affinity for specific body tissues

Question 26

how can cells respond to viral infections

Answer 26

no apparent change
death
transformation