Respiratory Tract Infections

Question 1

What are the frequent aetiological agents of the common cold? Is a laboratory diagnosis required? What is the treatment?

Answer 1

• rhinovirus, parainfluenza virus, RSV, enterovirus, coronavirus, HMPV
• lab diagnosis unnecessary
• specific treatment unavailable

Question 2

What are the frequent aetiological agents of pharyngitis/tonsillitis with nasal involvement? Is a laboratory diagnosis required? What is the treatment?

Answer 2

• adenovirus, enterovirus, parainfluenza, influenza
• • if nasal involvement much less likely to be a bacterial cause
• lab diagnosis if possible
• treatment if bacterial only

Question 3

What are the frequent aetiological agents of pharyngitis/tonsillitis with no nasal involvement?

Answer 3

• adenovirus, influenza, enterovirus, streptococcus pyogenes, streptococcus groups C and G
• 10-20% caused by bacteria –> need to treat strep with antibiotics
• • if there is a rash much more likely to be bacteria

Question 4

What are the frequent aetiological agents of sinusitis? Is a laboratory diagnosis required? What is the treatment?

Answer 4

• primary: viral (part of common cold)
• secondary: haemophilis influenzae, strep pneumonia
• • common cold virus can spread along the respiratory epithelium –> actue sinusitis
• -> once the epithelial cells are damaged become much more sensitive to secondary
• lab diagnosis rarely necessary
• treatment if bacterial and severe

Question 5

What are the frequent aetiological agents of otitis media? Is a laboratory diagnosis required? What is the treatment?

Answer 5

• pneumococci, haemophilis influenzae, M. catarrhalis
• viral infection doesn’t produce enough symptoms to cause child to seek medical attention
• lab diagnosis rarely necessary
• treatment if

Question 6

What are the frequent aetiological agents of epiglottitis? Is a laboratory diagnosis required? What is the treatment?

Answer 6

• haemophilis influenzae type b
• • this is very rare in countries that have vaccine
• lab diagnosis whenever possible (x-ray and blood culture, DO NOT TOUCH)
• treatment essential

Question 7

What are the frequent aetiological agents of croup? Is a laboratory diagnosis required? What is the treatment?

Answer 7

• parainfluenza virus, influenza, RSV
• lab diagnosis rarely necessary
• no specific treatment

Question 8

Which bacteria remains 100% susceptible to penicillin G?

Answer 8

Group A strep

Question 9

What are the frequent aetiological agents of acute bronchitis?

Answer 9

• usually part of viral URTI

Question 10

What are the frequent aetiological agents of acute exacerbations of chronic bronchitis?

Answer 10

• pneumococci and haemophilis influenzae

Question 11

What is chronic bronchitis?

Answer 11

Part of COPD, defined by how much sputum on how many days of the year
- can undergo acute exacerbations - bacterial infection with more purulent/bloody sputum than they had chronically

Question 12

What are the frequent aetiological agents of bronchiolitis?

Answer 12

• RSV

Question 13

What are the frequent aetiological agents of lung abscess?

Answer 13

• mixed anaerobes, staph, klebsiella

* * staph when the pneumonia resolves but there is some left in lung abscess

Question 14

What are the frequent aetiological agents of empyema?

Answer 14

• staph aureus, secondary to pneumonia

* pus in the pleural space

Question 15

What are the signs, symptoms and most common aetiological agents of acute bacterial pneumonia?

Answer 15

• chest pain, cough (may be productive of sputum w/ pus and blood), dyspnoea, shadows indicating consolidation on CXR, fever
• 7-10 days duration, tends to be lobar
• pneumococci, h. influenzae, staph, klebsiella
• • almost always caused by pneumococcus except in hospitals

Question 16

What is needed for a laboratory diagnosis of pneumonia?

Answer 16

Properly collected sputum sample

• good cough from deep in the lungs, better to collect in the morning
• transtracheal aspirate (must have polymorphs)