Mkaing an Infection Diagnosis Flashcards
What does microbiology do?
Identify the infection organism
Susceptibility testing
Identify clustered organisms over-represented in the community
Why do clinicians not use microbiology results?
Speed of progression of infection
They do not understand the implications of the data
What are the roles of clinical microbiologists?
Provide diagnostic test
Provide clinical consultation
Provide clinical advice on interpreting diagnostic tests
Provide advice on therapy of serious conditions
Manage control of infection
How do you make a microbiological diagnosis?
Direct examination
Culture
Serology
Molecular
What are the negatives and positives of direct examination?
Rapid
Simple to perform
Cheap
Not very sensitive
Not very specific
Requires expertise
What are the negatives and positives of culture diagnosis?
More sensitive
Allows susceptibility
Allows rapid presumptive diagnosis
Allows detailed identification
Rendered negative by antibiotics
Slow
What is serological diagnosis?
Looking at immune reponse
What are you looking at in a serological test?
Detect high IgG concentration
Detect rising of falling titres
Detect igM/IgA
Measure avidity of binding
Detect antigen
Example of serological technique
Agglutination
Precipitation
Example of molecular techniques
DNA hybridization
Nucleic acid amplification
To diagnose a UTI what sample is needed?
Midstream urine
To diagnose a wound injury, what sample is needed?
Pus of swab
To diagnose meningitis, what sample is needed?
CSF and blood
To diagnose pyrexia of unknown origin, what sample is needed?
Blood for culture and serology
To diagnose pneumonia what sample is needed?
Sputum, lavage, serology
