Viruses & Disease

Question 1

What is unique to each virus & can be used to identify them

Answer 1

The protein coat (capsid)

Question 2

Do viruses contain ribosomes

Answer 2

No

Question 3

Virus Life Cycle

Answer 3

• Virus binds to receptor on host cell
• Host replicates viral components
• New viruses assemble
• Viruses released from host cell

Question 4

6 modes of viral transmission

Answer 4

1. Oral transmission
2. Direct skin contact
3. Sexual transmission
4. Droplet transmission
5. Direct inoculation
6. Trans placental

Question 5

How has smallpox been eradicated

Answer 5

Variolation
Vaccination

Question 6

Is smallpox a DNA or RNA virus

Answer 6

DNA virus

Question 7

Where does the herpes virus lie dormant

Answer 7

In the trigeminal nerve

Question 8

Recurrence of herpes infection is causeed by what

Answer 8

• Immunosuppression
• Stress
• Insufficient sleep

Question 9

Different manifestations of herpes

Answer 9

• Cold sores
• Shingles
• Chickenpox

Question 10

Is herpes a DNA or RNA virus

Answer 10

DNA virus

Question 11

What happens in the life cycle of retroviruses that is different?

Answer 11

Reverse transcription of RNA to DNA occurs

Question 12

What is the target cell of HIV

Answer 12

CD4 lymphocyte (T cell)

Question 13

Steps in HIV retrovirus infection

Answer 13

• Virus binds to CD4 cell of host
• Viral RNA transcribed to DNA via reverse transcriptase (RT) enzyme
• Incorporates into host genome
• It replicates
• Released from host CD4 cell

Question 14

Function of CD4 T cell

Answer 14

Immune memory

Question 15

4 modes of transmission HIV

Answer 15

1. Unprotected sex
2. Blood transfusion
3. Needles (contaminated/sharing)
4. Mother to baby

Question 16

HIV therapies

Answer 16

• Education
• Clean needles
• Contraceptives
• Antivirals

Question 17

Antivirals used to treat HIV

Answer 17

• Combination anti retroviral therapy (ART)
• Nucleosides, Protease inhibitors, RT inhibitors
• HIV triple therapy
• Resistance - vaccines?

Question 18

Is HIV a DNA/ RNA virus

Answer 18

RNA virus

Question 19

4 zoonotic viruses

Answer 19

1. Influenza
2. HIV
3. Ebola
4. SARS-CoV-2

Question 20

Is SARS-CoV-2 a DNA/RNA virus

Answer 20

RNA virus

Question 21

How is SARS-CoV-2 spread

Answer 21

1. Via droplets
2. Persistence via mucus: virus remains in the airways

Question 22

What receptors does SARS-CoV-2 bind to

Answer 22

ACE2 receptors on host cells

Question 23

SARS-CoV-2 binds to ACE2 receptors where?

Answer 23

In the respiratory tract

Question 24

Which antibodies do vaccines induce

Answer 24

IgG antibodies

Question 25

Steps of zoonotic transmission of SARS-CoV-2

Answer 25

1. Virus is maintained in bats (reservoir hosts), undergoes 25-60 years of mutations
2. Virus jumps to susceptible species (intermediate hosts)
3. Virus jumps to humans through contact with infected animals (spillover to humans)
4. Virus spreads from person to person (human to human transmission)