Respiratory Infections

Question 1

How common are respiratory tract infections?

Answer 1

They are the most common source of childhood infections

Question 2

Give 6 examples of respiratory tract infections?

Answer 2

• Otitis media
• Nasopharyngitis
• Tonsillitis
• Sinusitis
• Bronchiolitis
• Pneumonia

Question 3

What is the most common virus causing respiratory tract infections?

Answer 3

Rhinovirus

Question 4

What kind of virus is rhinovirus?

Answer 4

Small RNA virus (picornavirus)

Question 5

What is the most common cause of bronchiolitis?

Answer 5

RSV

Question 6

Is pneumonia bacterial or viral?

Answer 6

Can be either, can can involve multiple viruses or viral/bacterial co-infection

Question 7

Give 2 examples of seasonal pathogens

Answer 7

• RSV

- Influenza

Question 8

When was routine seasonal influenza vaccination for younger children introduced?

Answer 8

In 2013

Question 9

How do respiratory infections usually begin?

Answer 9

With invasion of the pathogen in the nasopharynx

Question 10

What does the initial local immune response to a pathogen invading the nasopharynx involve?

Answer 10

An influx of neutrophils and cytokine secretion, in particular IL-8, IL-1ß, and IL-6

Question 11

What does an influx of neutrophils and cytokine secretion in the nasopharynx lead to?

Answer 11

Coryzal symptoms

Question 12

When might a pathogen invading the nasopharynx spread?

Answer 12

• If organism is particularly virulent
• If organism expresses appropriate surface molecules for receptors found elsewhere in the respiratory tract
• If there is an absence of systemic or mucosal immunity to the organism

Question 13

What are the categories of pulmonary defences?

Answer 13

• Physical

- Immune

Question 14

What are the physical respiratory defences?

Answer 14

• Nasal hairs
• Humidification
• Mucus
• Cilia

Question 15

How does the alveolar fluid aid in the immune response?

Answer 15

It contains antimicrobial compounds such as surfactant, complement, and lysozyme

Question 16

What immunoglobulin plays a major role in protection of the upper airway?

Answer 16

IgA

Question 17

What is the result of IgA having a major role in the protection of the upper airway?

Answer 17

Children with IgA deficiency have increased respiratory infections

Question 18

How long does a common cold usually take to resolve?

Answer 18

10-14 days

Question 19

How are most viral respiratory tract infections managed?

Answer 19

Only supportive therapy

Question 20

What can bacterial otitis media rarely progress to?

Answer 20

Mastoiditis and possibly meningitis

Question 21

What can sinusitis develop into?

Answer 21

Periorbital or orbital cellulitis, and then intra-cranial infection if untreated

Question 22

What can bacterial pneumonia be complicated by?

Answer 22

• Bacteraemia
• Empyema
• Necrotising pneumonia
• Lung abscesses

Question 23

What is the result of the potentially severe consequences of bacterial infections?

Answer 23

It is important to differentiate between bacterial and viral infections

Question 24

Why is it difficult to differentiate bacterial respiratory infections from viral?

Answer 24

• Difficulty of obtaining sterile samples from the respiratory tract
• Presence of potential pathogens in the nasopharynx of healthy children

Question 25

In whom does rhinovirus cause more significant illness

Answer 25

Children with asthma

Question 26

Why does rhinovirus cause more significant illness in children with asthma?

Answer 26

The virus penetrates deeper into the lungs

Question 27

Why does rhinovirus penetrate deeper into the lungs in children with asthma?

Answer 27

As their interferon-gamma response is blunted