Viral infection

Question 1

what 4 ways can virions be transmitted?

Answer 1

1) airborne
2) contact or faeces
3) contaminated water
4) blood

Question 2

what do you call virions that spread through the blood?

Answer 2

viremia

Question 3

how long does herpes simplex take to replicate in order to show symptoms?

Answer 3

2-8 days

Question 4

how long does hepatitis A take to replicate in order to show symptoms?

Answer 4

15-40 days

Question 5

what is incubation?

Answer 5

time the virus takes to replicate in order to show symptoms

Question 6

what are the many effects or interactions (4) that a virus may have with the host?

Answer 6

the virus may be:

1) oncogenic
2) lytic or acute
3) persistent or chronic
4) latent

Question 7

what is an acute or lytic virus?

Answer 7

enters the cell, replicates and destroys the cells to release virions

Question 8

what is an oncogenic virus?

Answer 8

it causes cancer

Question 9

what is a persistent or chronic virus?

Answer 9

a virus that remains constant

Question 10

what is a latent virus?

Answer 10

a virus that hides in the cell and is considered “silent”

Question 11

what is cytopathogenesis?

Answer 11

mechanisms by which viruses alter host on a cellular level.

Question 12

how does herpes simplex virus alter host on cellular level?

Answer 12

inhibits cellular protein synthesis

Question 13

how does herpesvirus modify host on a cellular level?

Answer 13

inhibition and degradation of cellular DNA

Question 14

what is syncytia?

Answer 14

giant multi-nucleated cell formed by fusion of a virally infected cell with a new cell.

Question 15

what are inclusion bodies?

Answer 15

it is an intracellular compartment composed of manipulated membrane and new viral components that stains densely.

Question 16

what virus causes this inclusion body refered to as nigri body?

Answer 16

rabies

Question 17

what virus causes this inclusion body refered to as owl eye?

Answer 17

CMV

Question 18

a nigri body by rabies is what?

Answer 18

intracytoplasmic inclusion

Question 19

an owl eye inclusion by CMV is what type of inclusion?

Answer 19

a basophilic intranuclear inclusion with a halo

Question 20

what virus causes a Cowdry type A inclusion?

Answer 20

Herpes simplex virus or VZV (varicella)

Question 21

what type of inclusion body is the Cowdry type A?

Answer 21

a eosinophilic intranuclear inclusion

Question 22

what virus causes this inclusion body?

Answer 22

Adenovirus pneumonia

Question 23

what type of inclusion body does the adenovirus pneumonia cause?

Answer 23

basophilic intranuclear

Question 24

what happens to the cell when poliovirus infects the cell?

Answer 24

it inhibits protein synthesis

Question 25

what happens to the cell when herpes simplex virus infects a cell?

Answer 25

it cuases inhibition of protein synthesis

Question 26

what will all enveloped viruses cause when they infect a cell?

Answer 26

they will alter the cell membrane through: 1) glycoprotein insertion **2) Sycncytia formation** 3) change the permeability

Question 27

what are the enveloped viruses?

Answer 27

1) herpes simplex virus 2) varicella (chicken pox; VZV) 3) HIV 4) paramixovirus 5) togavirus 6) herpesvirus

Question 28

what viruses will cause the body to be immunosuppressed?

Answer 28

HIV cytomegalovirus measles influenza

Question 29

chicken pox or VZV will cause what inclusion body? is it cytoplasmic or nuclear?

Answer 29

a guarneri inclusion body cytoplasmic

Question 30

what 2 viruses create owls eye inclusion bodies? is this inclusion body nuclear or cytoplasmic?

Answer 30

1) herpes simplex virus 2) chickenpox (VZV) nuclear

Question 31

what inclusion bodies does reovirus create?

Answer 31

acidophilic perinuclear bodies

Question 32

in what ways does a virus alter a host organ and system level?

Answer 32

1) organ failure by killing cells 2) immune reaction to the infection through cytokines 3) can induce autoimmune disease 4) prevents organ development

Question 33

what substance in the body gets released in order to control viral infection?

Answer 33

interferon alpha and beta

Question 34

what does inteferon do to virus?

Answer 34

it stops translation of viral replication

Question 35

how do natural killer cells kill virally infected cells?

Answer 35

by recognizing cells with down-regulated (missing) MHC 1

Question 37

what is a transient virus infection?

Answer 37

it is a virus that is cleared by the immune response

Question 38

what is a persistent viral infection?

Answer 38

the virus doesnt get cleared and the immune system keeps active

Question 39

what are the 3 types of persistent viral infection?

Answer 39

1) chronic 2) latent 3) recurrent

Question 40

what is a slow viral infection?

Answer 40

its a chronic persitent infection that has a long incubation period of moths to years

Question 41

what is a chronic persistent viral infection?

Answer 41

it is a virus that is continuously present

Question 42

what is a latent persistent viral infection?

Answer 42

a virus that has its genome present but does not produce virions

Question 43

what is a recurrent persistent viral infeciton?

Answer 43

latent infection that reactivates and produces virions before becoming active