Block E 3 Flashcards
viral disease
5 physical defences against viral infection
skin
mucus
ciliated epithelium
gastric acid
bile
3 examples of antigen non specific antiviral response
interferon, cytokines (TNF, IL-1)
nk cells and macrophages
fever
2 examples of antigen specific immune responses
T cell response
antibody
immune mediators for flu like symptoms (and examples)
interferon
lymphokines
resp viruses, arboviruses
immune mediators for delayed type hypersensitivity and inflammation
T cells
macrophages
polymorphonuclear leukocytes
enveloped viruses
immune mediators for immune complex disease
antibody
complement
Hep B, rubella
immune mediators for haemorrhagic disease
T cell
antibody
complement
dengue fever, measles
immune mediators for post infection cytolysis
T cells
enveloped viruses (eg post measles encephalitis)
immune mediators for immunosuppression
none
HIV, measles, rubella
producer cells of a-interferon
leukocytes
producer cells of b-interferon
fibroblasts
producer cells of y-interferom
T cells
NK cells
physical properties of a-interferon
acid stable
non glycosylated protein
physical properties of b-interferon
acid stable
glycoprotein
physical properties of y-interferon
acid-labile
glycoprotein
3 stages of interferon induction
-dsRNA (virus intermediates)
-viral inhibition of cellular protein synthesis
-enveloped virus interaction with rare blood leukocyte
4 stages of interferon mechanism of action
-release from intial infected cell
-INF bind to specific receptor on another cell
-INF induces antiviral state
(synthesis of protein kinase)
-stops protein synthesis that blocks viral replication
4 basic steps in viral disease
-acquisition
-inhibition of infection
-incubation period
-infection of target tissue
do abortive infections cause a virus production and what is the fate of the cell
no
no effect
do transformative infections cause a virus production and what is the fate of the cell
no
tumour
do cytolytic infections cause a virus production and what is the fate of the cell
yes
death
do chronic (nonlytic, productive) infections cause a virus production and what is the fate of the cell
yes
senescence
do latent infections cause a virus production and what is the fate of the cell
no
no effect
what does the cytopathologic activity of the virus change
changes in cells macromolecular synthesis
example of non specific histological changes that occur due to cytopathologic activity
vacuolisation
what can be said about the tissue and infection of inapparent infections
infected tissue undamaged
infection controlled before virus reaches target tissue
extent of damage is … in inapparent infections
below functional threshold
5 disease and viral factors that promote transmission
-stability of virion in environment
-transfer of virus into transmissible aerosols or secretions
-asymptomatic transmission
-ineffectiveness of immune response to control reoccurrence
8 mechanisms of viral transmission
-aerosols
-food, water
-fomites (tissue, clothes)
-sexual contact
-birth
-blood transfusion, injection, organ transplant
-zoonoses (animals, insect)
-genetic
examples of risk factors with viral transmission
age
health/nutrition/genetics
immune status
occupation
travel history
lifestyle
sexual activity
children
factors with geography and season that affect seronegative (susceptible people)
presense of cofactors in environment
habitat and season for arthropod vectors
winter
summer
