T3-L3: Infectious Test

Question 1

What features of history are important in the diagnosis of an infection?

Answer 1

• Travel History
• Occupation
• Animal Contact
• Hobbies/past times
• Sexual history

Question 2

How does a FBC vary in an infection?

Answer 2

In a bacterial infection - white cell count and neutrophil counts may be raised.

In a viral infection lymphocytes tend to be raised.

Question 3

What are procalcitonin and CRP markers of?

Answer 3

Inflammatory markers - raised markers support the diagnosis but negative markers make infection less likely.

Question 4

What assessment is used to determine the severity of pneumonia?

Answer 4

• CURB-65 Predicitive tool
• Blood lactate
• Blood gases

Question 5

What are the most common causes of community acquired pneumonia?

Answer 5

• Streptococcus pneumoniae

- Legionella pneumonia can be acquired during hotel stays

Question 6

Give methods of microbiological diagnosis.

Answer 6

• Culture - this allows identification, typing and sensitivity testing
• Direct detection
• Immunological tests

Question 7

How can we use antibody testing?

Answer 7

Used to confirm exposure to a specific micro-organism.

It is however restricted to patients with a detectable antibody response.
It is used retrospectively as it is often too late to inform antimicrobial therapy decisions.