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Microbiology Block 1 > Viral infection > Flashcards

Flashcards in Viral infection Deck (43)
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1
Q

what 4 ways can virions be transmitted?

A

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

2
Q

what do you call virions that spread through the blood?

A

viremia

3
Q

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

A

2-8 days

4
Q

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

A

15-40 days

5
Q

what is incubation?

A

time the virus takes to replicate in order to show symptoms

6
Q

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

A

the virus may be:

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

7
Q

what is an acute or lytic virus?

A

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

8
Q

what is an oncogenic virus?

A

it causes cancer

9
Q

what is a persistent or chronic virus?

A

a virus that remains constant

10
Q

what is a latent virus?

A

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

11
Q

what is cytopathogenesis?

A

mechanisms by which viruses alter host on a cellular level.

12
Q

how does herpes simplex virus alter host on cellular level?

A

inhibits cellular protein synthesis

13
Q

how does herpesvirus modify host on a cellular level?

A

inhibition and degradation of cellular DNA

14
Q

what is syncytia?

A

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

15
Q

what are inclusion bodies?

A

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

16
Q

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

A

rabies

17
Q

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

A

CMV

18
Q

a nigri body by rabies is what?

A

intracytoplasmic inclusion

19
Q

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

A

a basophilic intranuclear inclusion with a halo

20
Q

what virus causes a Cowdry type A inclusion?

A

Herpes simplex virus or VZV (varicella)

21
Q

what type of inclusion body is the Cowdry type A?

A

a eosinophilic intranuclear inclusion

22
Q

what virus causes this inclusion body?

A

Adenovirus pneumonia

23
Q

what type of inclusion body does the adenovirus pneumonia cause?

A

basophilic intranuclear

24
Q

what happens to the cell when poliovirus infects the cell?

A

it inhibits protein synthesis

25
Q

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

A

it cuases inhibition of protein synthesis

26
Q

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

A

they will alter the cell membrane through:

1) glycoprotein insertion

2) Sycncytia formation

3) change the permeability

27
Q

what are the enveloped viruses?

A

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

28
Q

what viruses will cause the body to be immunosuppressed?

A

HIV

cytomegalovirus

measles

influenza

29
Q

chicken pox or VZV will cause what inclusion body?

is it cytoplasmic or nuclear?

A

a guarneri inclusion body

cytoplasmic

30
Q

what 2 viruses create owls eye inclusion bodies?

is this inclusion body nuclear or cytoplasmic?

A

1) herpes simplex virus
2) chickenpox (VZV)

nuclear

31
Q

what inclusion bodies does reovirus create?

A

acidophilic perinuclear bodies

32
Q

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

A

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

33
Q

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

A

interferon alpha and beta

34
Q

what does inteferon do to virus?

A

it stops translation of viral replication

35
Q

how do natural killer cells kill virally infected cells?

A

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

36
Q
A
37
Q

what is a transient virus infection?

A

it is a virus that is cleared by the immune response

38
Q

what is a persistent viral infection?

A

the virus doesnt get cleared and the immune system keeps active

39
Q

what are the 3 types of persistent viral infection?

A

1) chronic
2) latent
3) recurrent

40
Q

what is a slow viral infection?

A

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

41
Q

what is a chronic persistent viral infection?

A

it is a virus that is continuously present

42
Q

what is a latent persistent viral infection?

A

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

43
Q

what is a recurrent persistent viral infeciton?

A

latent infection that reactivates and produces virions before becoming active