Week 7

Question 1

The classes of infectious agents that most commonly cause Respiratory infections include:

Answer 1

Viruses
Bacteria
Fungi - yeasts or filamentous (in immunocompromised people)

Question 2

For contact transmission, list an example of an aetiological agent that causes Respiratory infections, list what precautions are needed, and describe how the infectious agent gains access to the upper and/or lower respiratory tract:

Answer 2

Example
- streptococcus species
- staphylococcus species

Universal Precautions
- standard precautions (hand hygiene, respiratory etiquette, L2 or L3 surgical mask)
- droplet precautions

How does it gain access
- saliva
- indirect contact (droplet - Covid, influenza, rhinovirus, RSV)

Question 3

For common vehicle transmission, list an example of an aetiological agent that causes Respiratory infections, list what precautions are needed and describe how the infectious agent gains access to the upper and/or lower respiratory tract:

Answer 3

Example
- Tuberculosis

Universal Precautions
- Standard precautions (hand hygiene, respiratory etiquette etc)
- airborne precautions (single patient room, negative pressure room, fit tested n95 mask, dedicated patient equipment)

How does it gain access
- airborne

Question 4

What are the reasons for host susceptibility of respiratory infections in children

Answer 4

• don’t have an adequate immune response
• narrow airways
• putting things in their mouths
• born in healthcare setting

Question 5

What are the reasons for host susceptibility of respiratory infections in people who’ve had a laryngoscopy

Answer 5

• semi-critical item (disinfection but ideally sterile)
• disrupt mucous membrane
• aspiration
• disrupt innate defence (no gag/cough reflex, mucociliary escalator)
• innoculating lower upper respiratory tract with oral microbiota (translocating organisms)

Question 6

What are the reasons for host susceptibility of respiratory infections in people who smoke

Answer 6

• destroys ciliated cells (no movement of mucous)
• increased mucous production
• destruction of parenchymal

Question 7

Define endogenous respiratory infection reservoirs and describe one example

Answer 7

• Within the body (any area that’s exposed to the outside environment)
• e.g. Staphylococcus and Streptococcus species, candida albicans, Haemophilus, Neisseria

Question 8

Define exogenous respiratory infection reservoirs and describe one example

Answer 8

• external
• e.g. Bordatella pertussis, viruses (Covid, RSV), reservoir for the infectious agent is in the infected human

Question 9

Describe 3 key pieces of information you would collect when examining a patient with a suspected respiratory infection
Explain how this information can help with diagnosing the infection

Answer 9

1. Onset/Duration of symptoms - cough, cold, flu-like
   - stage of disease progression (shedding) - how infectious the person is
2. Any testing
   - accurate timely identification - treat or isolate
3. Smoker?/ Recent hospitalisation/ comorbidities
   - narrow the field for identifying the infectious agent
   - discharge within 48 hours (HAI, immunocompromised, baseline presentation)
4. Other - Immunisations, Travel