Infection tests Flashcards
1
Q
Examples of Non specific symptoms
A
- Fever, shaking, sweating
2
Q
Fever
A
- Temperature > 38
- ## chills, sweats, rigors
3
Q
Why carry out a diagnostic test
A
- To improve outcome
- To provide epidemiological data
4
Q
Bacterial infection blood count
A
- Raised WCC
- Normal or low lymphocytes
- Raised neutrophils
5
Q
Viral infection blood count
A
- Normal WCC
- Raised lymphocytes
- Normal neutrophils
6
Q
Inflammatory markers
A
- CRP - normal = <5mg/L
- Procalcitonin - normal = <0.5µg/L
7
Q
What is Procalcitonin
A
Procalcitonin is a reactive marker which helps differentiate between bacterial and viral infections; C-reactive protein is similar as it tells you where there is an inflammatory response
8
Q
Blood lactate and ABGs
A
useful to identify severe sepsis and respiratory failure
9
Q
Methods of microbiological diagnosis: Culture
A
- Establishes the presence of micro-organisms at a particular site
- Allows use of antimicrobial therapy
- Only detects cultivable organisms
- Slower than direct detection
10
Q
Gram stain
A
- Distinguishes between bacteria due to their cell walls
11
Q
Sensitivity testing
A
- Culture of micro-organisms in the presence of antimicrobial agent
- Work out if concentration of antimicrobial is high enough
- Measure zone of inhibition
12
Q
Sensitivity testing Uses and limitations
A
- Initial treatment is empirical - best guess
- Next treatment is targeted
- Correlation between antimicrobial sensitivity and clinical response is not absolute
13
Q
Direct detection (microscopy)
A
- Detection of the whole organism/component of organism such as an antigen or nucleic acid
- Establishes presence of microorganism at a particular site - cultivable and non-cultivable organisms
14
Q
Antigen detection
A
- Used at point of care
- rapid results
- Needs training and quality control
15
Q
Nucleic acid testing
A
- PCR is used to amplify DNA for testing
- Influenza, pneumonia etc
