Method | Purpose | |||||
Population freedom from infection | Individual animal freedom from infection prior to movement | Contribution to eradication policies | Confirmation of clinical cases | Prevalence of infection—surveillance (no clinical) | Immune status in individual animals or populations post-vaccination | |
Agent identification* | ||||||
Virus isolation | + | + | — | +++ | — | |
RT-PCR and qRT-PCR | + | + | ++ | +++ | ++ | — |
IHC | — | — | — | ++ | — | — |
IFA | — | — | — | ++ | — | — |
Detection of immune response† | ||||||
ELISA | +++ | +++ | +++ | + | +++ | +++ |
VNT | +++ | +++ | +++ | + | +++ | +++ |
Bead assays | +++ | +++ | +++ | + | +++ | +++ |
+++, recommended method; ++, suitable method; +, may be used in some situations, but cost, reliability or other factors severely limit application; —, not appropriate for this purpose. Although not all of the tests listed as +++ or ++ have undergone formal validation, their routine nature and the fact that they have been used widely without dubious results make them acceptable.
*A combination of agent identification methods applied on the same clinical specimen is recommended.
†One of the listed serological tests is sufficient. Reproduced with permission from OIE Terrestrial Manual, 7th ed. (May 2015 update).70
IFA, immunofluorescence assay; IHC, immunohistochemistry; RT-PCR, reverse transcriptase PCR; VNT, virus neutralisation test; qRT-PCR, quantitative RT-PCR.