Respiratory Tract Infections

Question 1

Respiratory innate defenses

Answer 1

• Nasal mucus
• Ciliated cells
• Mucociliary clearance elevator
• Alveolar macrophages
• Polymorphonuclear leucocytes
• Complement

Question 2

Mucociliary clearance elevator

Answer 2

• Particles are trapped in mucus covering the respiratory tract
• Ciliary action drags the mucus upwards
• Material is expectorated
• Disruption of system results in chronic infections e.g., cystic fibrosis, bronchiectasis.

Question 3

“CURB” scores

Answer 3

• Confusion of new onset (defined as an AMTS of 8 or less)
• Blood Urea nitrogen greater than 7 mmol/l (19 mg/dL)
• Respiratory rate of 30 breaths per minute or greater
• Blood pressure less than 90 mmHg systolic or diastolic blood pressure 60 mmHg or less
• Age 65 or older

Question 4

• Lobar pneumonia:

Answer 4

• Involvement of distinct region of the lung ie. lobe

Question 5

• Bronchopneumonia:

Answer 5

Diffuse, patchy consolidation

• Associated with bronchi and bronchioles

Question 6

• Interstitial pneumonia:

Answer 6

• Invasion of lung interstitium

* Usually characteristic of viral infection

Question 7

• Necrotising pneumonia:

Answer 7

• Lung abscesses and destruction of parenchyma

Question 8

Endemic

Answer 8

present in a community at all times, at a relatively low to medium frequency but at a steady-state

Question 9

• Epidemic:

Answer 9

Sudden severe outbreak within a region or a group

Question 10

• Pandemic

Answer 10

Occurs when an epidemic becomes widespread and affects a whole region, a continent, or the entire world.

Question 11

what makes a pandemic

Answer 11

• Antigenic shift
• Most people have no immunity
• Attack rate is high – it spreads rapidly
• Mortality can be high

Question 12

Influenza Vaccination

Answer 12

Tamiflu

• Antigenic variation means that a new vaccine is required each year
• New vaccine is based on the PREDICTED strains
• Trivalent vaccine
• New recombination methods speed up the process of developing a new vaccine - this was used in the recent swine flu pandemic
• Elderly, immunosuppressed and others with respiratory risk e.g., asthmatics and bronchitics require an annual vaccine

Question 13

importance of bacterial load

Answer 13

• Symptoms differ at different bacterial loads
• Patients present at different bacterial loads
• Diagnostic tests become positive at different bacterial loads
• Reducing the bacterial load can delay the diagnosis