10 Lung Infections

Question 1

List common community acquired bacteria

Answer 1

1. Streptococcus aureus
2. Streptococcus pneumoniae
3. Myxoplasma pneumoniae
4. Chlaymidophila pneumoniae
5. Haemophilus influenzae

Question 2

List common hospital acquired bacteria

Answer 2

1. Streptococcus aureus
2. Pseudomonas aeruginosa
3. Klebsiella
4. E coli

Question 3

State risk factors associated with respiratory bacterial infections

Answer 3

1. Age
2. Demographics (eg smoking)
3. Social factors (eg overcrowding)
4. Medications (eg steroids)
5. Medical history (eg HIV, liver disease)
6. Specific risk factors (eg contact with animals)

Question 4

What are the investigation methods for lung infections

Answer 4

Chest radiograph
Blood test
Arterial blood gases
Microbiological investigations

Question 5

How do you differentiate between acute bronchitis and pneumonia

Answer 5

Pneumonia:

• New symptoms and changes on X rays
• Pleuritic chest pain
• Usually hypoxic and confused

Acute bronchitis

• No changes to X ray
• Tracheal chest pain
• Cough

Question 6

What are the treatments for lung infections

Answer 6

1. Fluids
2. Analgesia
3. Oxygen
4. Nebulised saline
5. Antibacterial drugs - community and hospital acquired infections are treated very differently

Question 7

Name the community acquired viruses that cause lung infections

Answer 7

Rhinovirus
Influenza A or B
Respiratory syncytial virus

Question 8

What are the effects of viral infection on the lungs

Answer 8

Inflammation
Release of mediators
Immune memory

Damage to epithelial cells:

• Loss of cilia
• Bacterial growth
• Poor barrier to antigens
• Loss of chemoreceptors

Question 9

What is known to cause more severe viral lung infections

Answer 9

1. Highly pathogenic strain of flu

2. Absence of prior immunity
	Innate immunodeficiency	
	B cells (antibody- presumably local)
	T cells (correlate with peripheral levels?)

3. Weakened host immune response
   Frail elderly
   COPD/asthma
   Diabetes and heart disease etc.