Virus

Question 1

What is a virion?

Answer 1

Extracellular form of a virus which facilitates transmission from one host cell to another

Question 2

How to classify viruses?

Answer 2

Order
Family
Genus
Species

Question 3

How are viral families classified?

Answer 3

Based on genome structure
Mode of replication
Presence or absence of envelope

Question 4

Describe the structure of virus

Answer 4

The nucleic acids with its associated polymerase
Trapped in a protein capsid
Trapped in a lipid envelope
With spike proteins like antigens

Question 5

Describe viral replication

Answer 5

Virus attaches to the cell using spike protein (binds to receptor)
It leaves the protein coast outside
The genetic material is replicated
The spike proteins are copied and sent to the cell membrane
The nucleic acid reaches the membrane and leaves by exocytosis taking the spike proteins by budding

Question 6

What is vertical transmission?

Answer 6

Transmitting pathogens from the parent to the child using breast milk or placenta … just right after birth

Question 7

Give examples of zoonotic virus?

Answer 7

Rabies
Ebola

Question 8

What are host ranges?

Answer 8

What range of animals are affected by the virus
Coinfection with humans and other species can result in new strains of the virus

Question 9

What are the consequences of virus infection?

Answer 9

Overcome the virus and not get it again
Chronic gets worse over time like HIV
Latent infection
Transformation

Question 10

What is latent infection?

Answer 10

You get the infection and recover
Then it comes back as the virus hid in the body and reactivated
The viral genome is in the host but it’s not produced hence not detected

Question 11

What is a transformation infection?

Answer 11

The infection can transform into something more dangerous like a malignancy

Question 12

What is an example of latent virus?

Answer 12

Chickenpox in children and shingles in adults

Question 13

How can viral infections lead to cancer?

Answer 13

Modulation of apoptosis- virus stop this!
Modulation of cell cycle- virus causes excess proliferation
Can activate reactive oxygen species in the body

Question 14

Examples of virus causing cancer diseases

Answer 14

HPV can cause cervical cancer
Hepatitis B and C

Question 15

How to detect viruses?

Answer 15

Detect the whole organism
Detect parts of the organism
Detect the immune response to the pathogen

Question 16

How can we detect virus as a whole organism?

Answer 16

Seeing the virus under the electron microscope but it’s not specific
Or cultures which show the damage the virus can cause… still non specific

Question 17

How can we detect viruses as an antigen?

Answer 17

Lateral flow device
Add coloured or tagged specific antibodies
Detect the nucleic material using PCR by targeting the genome of the virus which is specific

Question 18

How can we detect a viral immune response?

Answer 18

Same as antigen but can use IgM and IgG testing

Question 19

What does IgM mean?

Answer 19

Indicates a current infection

Question 20

What does IgG mean?

Answer 20

Presence of infection now or prior

Question 21

All antivirals are virucidal. True or Falsekl

Answer 21

False
All are virustatic none are virucidal
Because then we need to kill the host cell

Question 22

What types of viral immunisations are there?

Answer 22

Vaccinations
Passive immunisation with immunoglobulins

Question 23

What is prophylaxis

Answer 23

A treatment to prevent disease.
Common with respiratory infections for the elderly

Question 24

What other measure can be taken in regards to viral infection control?

Answer 24

Screening like antenatal screening to protect the mother and the child
Testing
Social distancing