Respiratory tract infections

Question 1

What are the 3 types of influenza?

Answer 1

A, B and C

Question 2

Which influenza type is the commonest and most serious?

Answer 2

A is the most commonest and most serious

Question 3

What is the genetic material in the influenza virus?

Answer 3

RNA

Question 4

What does the influenza viral membrane have?

Answer 4

Viral membrane
with surface ‘spikes’
= glycoproteins:
– Neuraminidase (N)
&
– Haemaglutinin (H)

Question 5

what do point mutations in the influenza virus lead to?

Answer 5

Antigentic drift which results in epidemics such as the seasonal flu

Question 6

What does genetic reassortment lead to?

Answer 6

Antigenic shift which leads to pandemics

Question 7

What organisms may cause pharyngitis?

Answer 7

Viruses – various
 Strep pyognes (Group A Strep)*
 Epstein-Barr Virus
 Other Bacteria:
-Grp C G Streps
-Arcanobacterium
-Diphtheria

Question 8

What investigations do we carry out for phatyngitis?

Answer 8

 Throat culture (bacteria)
 Monospot
 EBV serology
 ASOT (for Grp A Strep)

Question 9

How do we diagnose group A strep?

Answer 9

Use a culture

Question 10

How does Group A strep appear on culture?

Answer 10

Beta-haemolytic

Question 11

What does group A strep react with?

Answer 11

Reacts with group A antiserum

Question 12

What is group A strep sensitive to?

Answer 12

Bacitracin-sensitive

Question 13

What is the usual bug for acute epiglottitis?

Answer 13

Haemophuluis influenzae = Hib

Question 14

What age individuals does Hib affect?

Answer 14

Approx 6 months to 6 years

Question 15

What other infections, other than Hib, cause acute epiglottitis?

Answer 15

Meningitis, Cellulitis,
Pneumonia

Question 16

What do you do with patients with acute epiglottitis?

Answer 16

Intubate ASAP;
Antibiotics- Ceftriaxone

Question 17

How does epiglottitis look like?

Answer 17

A thumbprint sign on an x-ray

Question 18

What is croup?

Answer 18

Acute viral laryngo-
tracheobronchitis

Question 19

What age group is affected by crop?

Answer 19

3 months to 3 years

Question 20

What is the treatment for croup?

Answer 20

Steam etc – placebo value (?)
Steroids – beneficial – single dose
Antibiotics – no role

Question 21

What is the pathophysiology of croup?

Answer 21

 Inflammation &
oedema of larynx & trachea
 Subglottic region –
least distensible part of
airway- prone to obstruction
 Infants: airways more
compliant
-inspiration reduces
pressure in trachea
-collapses
-stridor

Question 22

What is the single commonest cause of community acquired pneumonia?

Answer 22

Strep. pneumoniae

Question 23

What is the most significant organism in very severe community acquired pneumonia?

Answer 23

Legionella,
Staph aureus

Question 24

What are the lab tests for pneumonia?

Answer 24

– Sputum
– Blood Cultures
– Serum
– Urine (Antigen Kit)
– Throat swab (viral
testing)

Question 25

What are the advantages and disadvantages of sputum sample tests?

Answer 25

-Can grown pneumococcus, staph aureus, coliforms and haemophilus
-However if there is a prior us of antibiotics, or mixture of salivary/mucoid makes test useless

Question 26

What are the advantages of urinary antigen test for pneumonia?

Answer 26

-Quick
-Result not impacted by antibiotics

Question 27

What are the causes of exasperated COPD?

Answer 27

-Bacterial infection
-Viral infection like RSV, flu, paraflu
-Non-infective causes like cold, allergens

Question 28

What are the problems in investigations in COPD patients?

Answer 28

-Chronic sputum production
-Chronic colonisation with bacteria

Question 29

What is the treatment for COPD exacerbation?

Answer 29

 Maintain oxygenation
 Treat (possible) underlying cause
Amoxicillin 500mg tds/doxycycline
 Treat airways obstruction
– bronchodilators
– corticosteroids
 Hydration/nutrition