Serology and Immunodiagnostics Flashcards
Define Immunodiagnostics
The measurement of antigen-antibody interactions for diagnostic purposes
What does serology mainly measure?
The presence of antibodies in body fluids
What can immunodiagnostics help you to determine diagnostically?
-Can use to detect or quantify an antigen of interest
-Can determine exposure to an infectious agent
-can look for antibodies to determine exposure/disease/immunity
How can an antibody test be used to determine if an animal is clinically affected by a certain pathogen?
You need at least 2 samples taken 2-3 weeks apart that show at least a 4 fold rise in titer
-must also have clinical signs
Define sensitivity
A tests ability to designate an individual with disease/exposure as positive, truly identifying disease
-amount of false negatives
Define specificity
A tests ability to designate an individual that does not have a disease as negative, truly identifying lack of disease
- amount of false positives
What is the difference between direct and indirect fluorescent antibody tests?
Direct: identifies the presence of antigen in tissue
Indirect: measures antibodies in serum or antigen in tissue (can assess for both antibody and antigen)
What do agglutination tests measure?
Antibodies
What do virus neutralization assays measure
Antibodies that neutralize the virus of interest
-requires live cells and viruses
What is an antibody titer?
The highest dilution/lowest concentration of antibody that will detectably interact with the antigen
In what situations is serology especially useful?
1.Retrovirus infections or other chronic infections
2. To establish a “disease free status” in a herd
3. Leptospirosis diagnosis
4. Tiers for making vaccine decisions
5. IgM testing (WNV)
6. Parasitic diseases
7. regulatory testing
8. Systemic mycoses diagnosis
9. Tick-borne disease testing
