Viruses Flashcards

1
Q

Describe why viruses can not be described as cells.

A

Cannot replicate independently of a host cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the 3 types of virus shapes?

A

Icosahedral - 20 equilateral triangle faces

Helical

Complex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Most viruses have tissue tropism. What does this mean?

A

Specific host range

Only infect specific type of host cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the name given to the extracellular form of a virus?

A

Virion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe the structure of a virion.

A

Nucleic acid genome and associated polymerases surrounded by protein capsid (coat)

This is surrounded by a lipid envelope (sometimes) with attachment proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How does a virus synthesise it’s protein coat?

A

It doesn’t

It steals it from the host cell that produced it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the 3 routes of transmission for HIV?

A

Blood-borne
Sexual
Vertical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What other viral infection has the same transmission routes as HIV?

A

Hepatitis B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Aside from HIV and Hep B, what virus is transmitted via blood?

A

Hepatitis C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What viruses are transmitted via the faecal-oral route?

A

Hepatitis A
Hepatitis E
Polio

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What viruses can be caught via droplet infection?

A

Influenza

RSV (Respiratory syncytial virus)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the method of transmission of measles?

A

Airborne

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Aside from measles, what other virus undergoes airborne transmission?

A

Chickenpox

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Herpes simplex, CMV and EBV are transmitted through what?

A

Close contact

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Vector borne viruses are spread by bugs. Give 3 examples of vector borne viruses, and what insect spreads them.

A

Dengue
Yellow fever
Chikungunya

All 3 spread by mosquitoes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Rabies, MERS and Ebola are viruses spread through what route of transmission?

A

Zoonotic

17
Q

What is viral latency?

A

The virus lying dormant in the cells of the organism

Few viral antigens and no viral particles are produced

18
Q

Give an example of a virus that undergoes latency.

Not HIV

A

Herpes simplex

Varicella zoster

19
Q

Viral infection can often lead to cancer. What 3 ways can this occur?

A

Affects cell cycle modulation - drives cell proliferation

Prevention of apoptosis (programmed cell death)

Reactive oxygen species mediated damage
(Persistent inflammatory processes can lead to cancer via reactive oxygen species)

20
Q

There are 3 basic ways to detect a virus, what are they?

A

Detect the whole virus

Detect part of the virus - antigens / nucleic acids

Detect an immune response to a pathogen - antibodies

21
Q

One way of detecting ‘the whole virus’ is through microscopy. What is the other way?

A

Culture

22
Q

‘All antiviral agents are virustatic, and not virucidal.’

What does this mean?

A

Virustatic agents prevent the growth and development of viruses, whereas virucidal agents destroy viruses.

So treatment only aims to prevent viruses from replicating, but will not kill the viruses themselves.

23
Q

Some antiviral therapy is prophylactic. What does this mean?

A

To prevent infection = prophyaxis

24
Q

Some antiviral therapy is utilised when there is evidence of infection/replication, but no symptoms are yet present. What is this called, and when is it often done?

A

Pre-emptive therapy

Often done after surgery and/or on immuno-suppressed patients

25
Q

What is the purpose of suppressive therapy?

A

Keep viral replication below the level that would cause tissue damage in an asymptomatic infected patient

26
Q

Summarise what types of antiviral therapy there are…

A

Prophylactic
Pre-emptive
Overt
Suppressive

27
Q

What major viruses have been eradicated recently?

A

Measles

Polio

28
Q

Use a single word to describe the consequence of viral infection…

A

Syndromes

29
Q

Respiratory syndromes are caused by what?

A

Influenza
Measles
Chickenpox

30
Q

What viruses cause neurological syndromes to develop?

A
Rabies 
Polio 
Enterovirus 
HSV 
VZV
31
Q

Dengue fever, rubella, parvovirus and chikungunya cause arthralgia.

What is arthralgia?

A

Joint pain

32
Q

Gastroenteritis sydromes are causes by what?

A

Norovirus
Rotavirus
Adenovirus

33
Q

Aside from Haepatitis A, B, C, D & E, what viruses are responsible for the development of Hepatitis syndromes?

A

CMV
EBV
Yellow fever

34
Q

Enteroviruses cause neurological syndromes and what else?

A

Skin infections

35
Q

What does HSV cause?

A

Neurological syndromes

Skin infections

Eye infections

36
Q

CMV, Rubella, VZV and parvovirus are responsible for causing what syndromes?

A

Congenital abnormalities (birth defects)

37
Q

Lymphadenopathy refers to disease causing abnormalities in the size of lymph nodes. What viruses can cause this?

A

HIV

CMV

EBV

38
Q

What viruses are responsible for causing eye infections?

A

HSV
VZV
Adenovirus

39
Q

What are the 3 mechanisms for which a viral infection can lead to cancer

A

Modulation of cell cycle control

Modulation of apoptosis

Reactive oxygen species mediated damage