L83 - Viral Pathogenesis 1

Question 1

To caus einfection a virus must?

Answer 1

Gain Entry

Mutiply and Spread

Target appropriate organ

Question 2

To be maintained in nature a virus must?

Answer 2

shed into the environment

or taken up by an arthropod vector or needle

or passed congenitaly

Question 3

Local and Systemic Replicaiton refers to

Answer 3

Local - confined to the organ of entry

Systemic - involving many organs

Question 4

Tropism

Answer 4

Anatomical Localisation of infection

Question 5

Route of Entry:

Answer 5

conjunctiva
resp tract
alimentary tract
urogenital
parenteral inoculation
skin (most viruses enter via epithelial cells of th emucosa because the epidermis of the skin is covered by dying cells covered with keratin and provides a hostile enviro for viruses)

Question 6

How d viruses get from the epithelium into the blood

Answer 6

Lymphatics

Question 7

2 methods of Antibody mediated pathology?

Answer 7

Ab dependent ehancement of infection

Antigen antibody complexes

Question 8

What is antibody dependent enhancement of infection

Answer 8

FcR mediated uptake of Virus Ab complexes into cells

i.e. Dengue haemorrhagic fever/shock syndrome

Question 9

Why are antigen Antibody compexes

Answer 9

Deposited int he kidney can cause glomerularnephritis and int he blood vessel vasculitis

i.e. Hep B in chronic carriers