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Principles of dizzees > Viruses > Flashcards

Flashcards in Viruses Deck (39):
1

Describe why viruses can not be described as cells.

Cannot replicate independently of a host cell

2

What are the 3 types of virus shapes?

Icosahedral - 20 equilateral triangle faces

Helical

Complex

3

Most viruses have tissue tropism. What does this mean?

Specific host range

Only infect specific type of host cell

4

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

Virion

5

Describe the structure of a virion.

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

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

6

How does a virus synthesise it's protein coat?

It doesn't

It steals it from the host cell that produced it

7

What are the 3 routes of transmission for HIV?

Blood-borne
Sexual
Vertical

8

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

Hepatitis B

9

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

Hepatitis C

10

What viruses are transmitted via the faecal-oral route?

Hepatitis A
Hepatitis E
Polio

11

What viruses can be caught via droplet infection?

Influenza
RSV (Respiratory syncytial virus)

12

What is the method of transmission of measles?

Airborne

13

Aside from measles, what other virus undergoes airborne transmission?

Chickenpox

14

Herpes simplex, CMV and EBV are transmitted through what?

Close contact

15

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

Dengue
Yellow fever
Chikungunya

All 3 spread by mosquitoes

16

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

Zoonotic

17

What is viral latency?

The virus lying dormant in the cells of the organism

Few viral antigens and no viral particles are produced

18

Give an example of a virus that undergoes latency.

(Not HIV)

Herpes simplex
Varicella zoster

19

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

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

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

Detect the whole virus

Detect part of the virus - antigens / nucleic acids

Detect an immune response to a pathogen - antibodies

21

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

Culture

22

'All antiviral agents are virustatic, and not virucidal.'

What does this mean?

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

Some antiviral therapy is prophylactic. What does this mean?

To prevent infection = prophyaxis

24

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?

Pre-emptive therapy

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

25

What is the purpose of suppressive therapy?

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

26

Summarise what types of antiviral therapy there are...

Prophylactic
Pre-emptive
Overt
Suppressive

27

What major viruses have been eradicated recently?

Measles
Polio

28

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

Syndromes

29

Respiratory syndromes are caused by what?

Influenza
Measles
Chickenpox

30

What viruses cause neurological syndromes to develop?

Rabies
Polio
Enterovirus
HSV
VZV

31

Dengue fever, rubella, parvovirus and chikungunya cause arthralgia.

What is arthralgia?

Joint pain

32

Gastroenteritis sydromes are causes by what?

Norovirus
Rotavirus
Adenovirus

33

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

CMV
EBV
Yellow fever

34

Enteroviruses cause neurological syndromes and what else?

Skin infections

35

What does HSV cause?

Neurological syndromes

Skin infections

Eye infections

36

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

Congenital abnormalities (birth defects)

37

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

HIV

CMV

EBV

38

What viruses are responsible for causing eye infections?

HSV
VZV
Adenovirus

39

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

Modulation of cell cycle control

Modulation of apoptosis

Reactive oxygen species mediated damage