Respiratory Syncytial Virus

Question 1

Describe the structure of RSV

Answer 1

1. (-) RNA single strand
2. Not segmented
3. HA & NA are part of same glycoprotein
4. Have F-protein and G-protein

Question 2

Compare and contrast structural features of RSV (paramyxoviridae) and influenza (orthomyxoviridae) (2)

Answer 2

RSV:

1. Structure:

• (-) ssRNA
• Linear, no-segmented genome
• Enveloped
• Replicate in the cytoplasm

2. Has fusion (F) protein
3. HA and Na are part of the same glycoprotein

Influenza:

1. Structure:

• (-) ssRNA
• Linear, segmented genome
• Enveloped
• Replication in the nucleus

2. No F protein
3. HA and NA are two separate proteins

Question 3

What are the 3 big things when we think about Paramyxoviridae infection?

Answer 3

1. Lungs
2. Kids
3. Viremia

Question 4

Where do paramyxoviridae replicate in the body (not cell)?

Answer 4

All replicate in upper respiratory tract

Question 5

Where do paramyxoviridae commonly infect host?

Answer 5

1. Children: lower respiratory infection (eg. pneumonia)
2. Adult: upper respiratory infection (colds)

Question 6

How do paramyxoviridae spread inside host?

Answer 6

Viremia: dissemination of virions in blood to distant sites

Question 7

Function of G protein in RSV

Answer 7

Initial binding of virus to host

Question 8

Functions of F protein in RSV (2)

Answer 8

1. Fusion viral envelope to host cell
2. Fusion infected cell membranes to each other –> syncytia

Question 9

What signs and symptoms will be seen clinically?

Answer 9

1. Respiratory distress
2. Hear wheezing/rhonchi on auscultation
3. Hypoxia
4. Copious secretions

Question 10

List 3 tests for RSV and their advantages/disadvantages

Answer 10

1. Cell culture – takes more time
2. Direct antigen detection (rapid test) – not very sensitive/accurate
3. PCR – most accurate and quick in many places

Question 11

Different methods to prevent RSV? (2)

Answer 11

1. Respigam
2. Palavisumab (Synagis)

Question 12

1. What is Respigam?
2. Benefit of Respigam

Answer 12

1. Respigam is a human pooled antibody with high RSV titers
2. Shown to have a decrease in disease severity and hospitalization

Question 13

1. What is Palavisumab?
2. Features of Palavisumab (3)

Answer 13

1. A mouse monoclonal anti-RSV antibody

• Once monthly IM injection during RSV season
• For high risk groups and young children
• Very expensive