Viral pathogenicity 2

Question 1

Outcome of virus infection of a cell

Answer 1

• cytolytic or cytocidal infection (cell death)
• Chronic infection
• Latency
• Transformation

Question 2

What is chronic infection

Answer 2

Continuous viral replication within cell, but cell survives.

Cells can have housekeeping function and ‘luxury’ functions. A chronic infection is more likely to interfere with the ‘luxury’ functions hence why the host cell doesn’t die

Question 3

Whats latency

• How can replication be reactivated
• What are the two types of infection

Answer 3

NO virus replication, no production of viral proteins

• But viral genome is still sitting within the cell.
• Once infected, always infected
• Virus replication can be reactivated
• Primary and secondary infections

Question 4

What is an example of a latent disease

Answer 4

i.e. cold sores.

Can be in latency state and then reactivate

Question 5

what is transformation

Answer 5

-Immortalisation of cell (i.e. stimulate cell to divide forever)

Question 6

What in the skin is a barrier to viruses

Answer 6

Keratin

Question 7

How can virus enter host

Answer 7

• Mucosal surfaces (which are non keratinized)
• Respiratory tract
• Gastrointestinal tract (by food or water)
• Placenta

Question 8

How can virus spread within host

Answer 8

Local (i.e. cell to cell)
Lymphatics
Bloodstream (viremia)
Axonal pathways (up and down nerves)

Question 9

What is interaction with target cells determined by

Answer 9

Tropism of virus

Question 10

How do viruses get out of one individual to get to another individual

Answer 10

• skin (vesicles/ blisters)
• Respiratory tract (droplets)
• Gastrointestinal tract- saliva and faeces
• Urogenital tract-urine, semem, female genital tract secretions
• Blood (blood borne viruses)
• breast milk