Pandemic Viruses

Question 1

Examples of zoonoses:
1)
2)
3)

Answer 1

1) Bats - Lyssavirus (rabies-like), hendravirus (encephalitis, pneumonia), SARS coronavirus
2) Birds - Influenza
3) Monkeys - HIV

Question 2

SARS case definition:
1)
2)
3)
4)
5)

Answer 2

1) Fever over 38 degrees C
2) Cough
3) Progressive shortness of breath
4) X-ray evidence of atypical pneumonia
5) Travel to Asia or exposure to SARS patient in the past ten days

Question 3

SARS transmission

Answer 3

Sneezing and coughing

Less infectious than influenza

Question 4

SARS discovery as a coronavirus

Answer 4

Growth in vero cells

Growth only stained (fluorescence assay) from patient sera (uninfected sera did not stain)

Question 5

Natural host of SARS

Answer 5

Bats

Question 6

Human flu receptor

Answer 6

SA alpha 2-6 Gal

Question 7

Avian flu receptor

Answer 7

SA alpha 2-3 Gal

Question 8

Number of amino acid changes to change selectivity from SA alpha 2-3 Gal to SA alpha 2-6 Gal

Answer 8

One

Question 9

Subtype of Spanish flu

Answer 9

H1N1

Question 10

Subtype of Asian flu

Answer 10

H2N2

Question 11

Subtype of Hong Kong flu

Answer 11

H3N2

Question 12

Animal with both alpha 2-3 and alpha 2-6 receptors

Answer 12

Pig

Question 13

Significance of pigs in influenza evolution

Answer 13

1) If both avian and human strains infect a single cell, 16 gene products produced.
2) Gene products mix.
3) If avian HA and NA mix with genes allowing virus to grow well in humans –> pandemic

Question 14

Reason for H5N1 systemic infection

Answer 14

HA hydrophobic residue has mutated. Can be cleaved by enzymes at most body sites, not just tryptase Clara

Question 15

Spanish flu symptoms:

Answer 15

1) Pulmonary oedema
2) Haemmorhage
3) Cyanosis
Death within 5 days