Parainfluenza

Question 1

What type of genetic material do parainfluenza viruses (PIV) have?

Answer 1

Single-stranded, negative-sense RNA

Question 2

To which virus family do parainfluenza viruses belong?

Answer 2

Paramyxoviridae

Question 3

Are parainfluenza viruses enveloped or non-enveloped?

Answer 3

Enveloped

Question 4

Mention the four major serotypes of human PIV.

Answer 4

• PIV-1
• PIV-2
• PIV-3
• PIV-4

Question 5

T/F. PIVs don’t have hemagglutinin and neuraminidase.

Answer 5

False

Question 6

What are the structural characteristics of parainfluenza virions?

Answer 6

• Pleomorphic
• Lipid bilayer envelope derived from host cell

Question 7

Mention the 6 viral proteins encoded by PIV’s RNA.

Answer 7

• Nucleocapsid protein (NP)
• Phosphoprotein (P)
• Matrix protein (M)
• Fusion glycoprotein (F)
• Hemagglutinin-neuraminidase glycoprotein (HN)
• RNA polymerase (L)

Question 8

What proteins are targets for neutralizing antibodies?

Answer 8

HN and F proteins

Question 9

Which proteins make the nucleocapsid core?

Answer 9

NP, P and L

Question 10

This glycoproteins are critical for attaching the virus to the host cell wall.

Answer 10

HN proteins

Question 11

After attachment, this protein mediates virus-cell membrane fusion and infection.

Answer 11

F protein

Question 12

Where does viral replication occur?

Answer 12

Cytoplasm

Question 13

What shape does the nucleocapsid has?

Answer 13

Helical

Question 14

Which cells do PIVs preferentially infect?

Answer 14

Cilliated epithelial cells

Question 15

Where does initial replication occur?

Answer 15

Epithelial cells of the nose and oropharynx

Question 16

How is parainfluenza virus transmitted?

Answer 16

• Direct person-to-person contact via large respiratory droplets
• Contact with fomites contaminated with respiratory secretions

Question 17

At what age does initial PIV infection typically occur?

Answer 17

Before the age of 5

Question 18

Which PIV serotype affects up to 50% of children within their first year of life?

Answer 18

PIV-3

Question 19

When do PIV-1 and PIV-2 typically cause initial infections?

Answer 19

Between ages 3 and 5

Question 20

T/F. PIV is the second most common viral cause of hospitalization in children.

Answer 20

True

Question 21

Primary disease associations for PIV-1 and PIV-2.

Answer 21

Croup (Laryngotracheobronchitis) in children

Question 22

Primary disease associations for PIV-3.

Answer 22

Pneumonia and bronchiolitis

Question 23

Primary disease associations for PIV-4.

Answer 23

Mild upper respiratory infections

Question 24

When do PIV-1 and PIV-2 cause seasonal outbreaks?

Answer 24

During fall

Question 25

When does PIV-3 cause epidemics?

Answer 25

During spring

Question 26

Which PIV serotype is more common in the autumn and winter months?

Answer 26

PIV-4

Question 27

What range of illness severity can PIV infections cause?

Answer 27

From mild cold-like symptoms to life-threatening pneumonia

Question 28

T/F. Most PIV infections require hospitalization.

Answer 28

False

Question 29

What type of respiratory infections are more common in children?

Answer 29

Upper respiratory infections

Question 30

What complications can arise from upper respiratory tract PIV infections in children?

Answer 30

Otitis media and sinusitis

Question 31

What are the typical symptoms of PIV-induced croup?

Answer 31

* Fever, rhinorrhea, pharyngitis * Barking cough, stridor, dyspnea, chest wall retractions

Question 32

T/F. PIV-2 disease is generally less severe than PIV-1.

Answer 32

True

Question 33

Which PIV serotype is associated with distal lung involvement, particularly in infants under 6 months old?

Answer 33

PIV-3

Question 34

Which PIV serotype is usually associated with mild upper respiratory infections or asymptomatic infections?

Answer 34

PIV-4

Question 35

What are the three primary methods for diagnosing PIV?

Answer 35

* Culture * Antigen detection * PCR

Question 36

What are the best specimens for diagnosing PIV?

Answer 36

Swabs, aspirates, and washes from the nasopharynx or orophraynx

Question 37

T/F. There are rapid antigen kits for PIV detection.

Answer 37

False; there aren't

Question 38

T/F. There are no proven antiviral treatments for parainfluenza.

Answer 38

True

Question 39

T/F. There is no vaccine approved for parainfluenza virus.

Answer 39

True