Viruses

Question 1

Which virus are these illnesses caused by?
Common cold
Winter vomiting disease 
Chickenpox
Shingles
Glandular fever

Answer 1

Rhinovirus
Norovirus 
Varicella Zoster
Herpes Zoster
Epstein-Barr

Question 2

Features of viruses

Answer 2

• Dependent on infection of host cell for metabolism and replication
• Very small (1/100th size of bacteria)
• Protein core surrounding genetic material (DNA/RNA)

Question 3

Example of a latent infection

Answer 3

Varicella Zoster Virus

- Becomes dormant in sensory nerve roots and can reactivate years later

Question 4

Example of a chronic infection

Answer 4

Hep C virus (can cause liver inflammation for years)

Question 5

Example of an acute infection

Answer 5

Norovirus infects hosts for days

Question 6

Which viral infections can contribute to cancers?

Answer 6

1. Epstein-Barr virus (EBV)
2. Hepatitis B virus (HBV)
3. Human Papilloma virus (HPV)

Question 7

What does EPV affect?

Answer 7

Infects immune system cells (B cells) and epithelial cells of mouth and nose

Usually causes mild illness (e.g. glandular fever)

Can causes latent lifelong infection

Question 8

How can EPV contribute to cancers?

Answer 8

Contributes to certain cancers with other factors

Lymphoma in HIV infection

Nasopharyngeal carcinoma (especially in Southern China)

Question 9

How can HBV contribute to cancer?

Answer 9

May develop chronic infection that leads to cirrhosis

Resulting damage leads to increased risk of liver cancer

Question 10

How can HPV contribute to cancer?

Answer 10

Virus may survive for years, eventually leads to conversion of normal cells on surface of cervix into cancerous cells

Question 11

What viral disease is transmitted by Aedes mosquito?

Answer 11

Dengue fever