Viral infection Flashcards Preview

Microbiology Block 1 > Viral infection > Flashcards

Flashcards in Viral infection Deck (43):
1

what 4 ways can virions be transmitted?

1) airborne 

2) contact or faeces

3) contaminated water

4) blood 

2

what do you call virions that spread through the blood?

viremia 

3

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

2-8 days

4

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

15-40 days

5

what is incubation?

time the virus takes to replicate in order to show symptoms 

6

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

the virus may be:

1) oncogenic 

2) lytic or acute

3) persistent or chronic

4) latent

7

what is an acute or lytic virus?

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

8

what is an oncogenic virus?

it causes cancer

9

what is a persistent or chronic virus?

a virus that remains constant 

10

what is a latent virus?

a virus that hides in the cell and is considered "silent"

11

what is cytopathogenesis?

mechanisms by which viruses alter host on a cellular level.

12

how does herpes simplex virus alter host on cellular level?

inhibits cellular protein synthesis

13

how does herpesvirus modify host on a cellular level?

inhibition and degradation of cellular DNA

14

what is syncytia?

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

15

what are inclusion bodies?

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

16

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

Q image thumb

rabies

17

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

CMV

18

a nigri body by rabies is what?

intracytoplasmic inclusion

19

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

a basophilic intranuclear inclusion with a halo

20

what virus causes a Cowdry type A inclusion?

Q image thumb

Herpes simplex virus or VZV (varicella)

21

what type of inclusion body is the Cowdry type A?

a eosinophilic intranuclear inclusion

22

what virus causes this inclusion body?

Q image thumb

Adenovirus pneumonia

23

what type of inclusion body does the adenovirus pneumonia cause?

basophilic intranuclear

24

what happens to the cell when poliovirus infects the cell?

it inhibits protein synthesis

25

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

it cuases inhibition of protein synthesis

26

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

they will alter the cell membrane through:

1) glycoprotein insertion

2) Sycncytia formation

3) change the permeability

27

what are the enveloped viruses?

1) herpes simplex virus

2) varicella (chicken pox; VZV)

3) HIV

4) paramixovirus

5) togavirus

6) herpesvirus

28

what viruses will cause the body to be immunosuppressed?

HIV

cytomegalovirus

measles

influenza

29

chicken pox or VZV will cause what inclusion body?

is it cytoplasmic or nuclear?

a guarneri inclusion body

cytoplasmic

30

what 2 viruses create owls eye inclusion bodies?

is this inclusion body nuclear or cytoplasmic?

1) herpes simplex virus

2) chickenpox (VZV)

nuclear

31

what inclusion bodies does reovirus create?

acidophilic perinuclear bodies

32

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

1) organ failure by killing cells

2) immune reaction to the infection through cytokines

3) can induce autoimmune disease

4) prevents organ development

33

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

interferon alpha and beta

34

what does inteferon do to virus?

it stops translation of viral replication 

35

how do natural killer cells kill virally infected cells?

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

36

37

what is a transient virus infection?

it is a virus that is cleared by the immune response

38

what is a persistent viral infection?

the virus doesnt get cleared and the immune system keeps active

39

what are the 3 types of persistent viral infection?

1) chronic

2) latent

3) recurrent

40

what is a slow viral infection?

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

41

what is a chronic persistent viral infection?

it is a virus that is continuously present 

42

what is a latent persistent viral infection?

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

43

what is a recurrent persistent viral infeciton?

latent infection that reactivates and produces virions before becoming active