Infection Diagnosis Flashcards
What does microbiology do?
Identify infecting organism
Susceptibility testing
Identify clusters organisms over-represented in community
Importance of identifying infecting organism I microbiology:
Diagnostic advice
Importance of susceptibility testing in microbiology:
Treatment advice
Importance of identifying clustered organisms in microbiology:
Infection and outbreak control
What are laboratory tests for?
Doctor’s back up
Help when antibiotics are unpredictable
Provide intelligence system
Detection of outbreak samples
Permit collection of alert organisms
Why do clinicians not use microbiology results?
Speed of progression much faster than time taken to generate results
Difficult to understand implications of data - very complex
Roles of clinical microbiologist:
High quality diagnostic tests
Clinical consultation service
Clinical advice
Advice on therapy of serious infections
Manage control of infection issues within hospital
How do you make a microbiological diagnosis?
Direct examination
Culture
Serology
Molecular
Advantages of a smear diagnosis:
Rapid
Simple
Cheap
Disadvantages of smear diagnosis:
Not very sensitive + specific
Requires considerable expertise
What does light microscopy involve?
Direct (parasites)
Gram stain (CSF - bacteria)
Z-N (sputum - TB)
Giemsa stain (blood - malaria)
What does fluorescent microscopy involve?
Respiratory syncytial virus (RSV) diagnosis
What does electron microscopy involve?
Virus detection and identification
Advantages of culture diagnosis:
More sensitive than spear
Susceptibility testing
Rapid
Detailed identification
Disadvantages of culture diagnosis:
Rendered negative by antibiotics - bacteria less likely to grow
