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→Laboratory Tests
===Laboratory Tests===
===Laboratory Tests===
Laboratory testing is required to confirm a diagnosis of classical swine fever. As well as collection of tissues for histopathology, samples of tonsils, spleen, lymph nodes, kidney and distal ileum are taken for virus detection. Virus may be detected by fluorescent antibody detection, ''in situ'' hybridisation, immunoperoxidase staining or virus isolation. These methods are reviewed in Moennig<sup>1</sup> and briefly described below.
Laboratory testing is required to confirm a diagnosis of classical swine fever. As well as collection of tissues for histopathology, samples of tonsils, spleen, lymph nodes, kidney and distal ileum are taken for virus detection. Virus may be detected by fluorescent antibody detection, ''in situ'' hybridisation, PCR, immunoperoxidase staining or virus isolation.
The gold standard laboratory test for CSFV is virus isolation in cell culture. In viraemic animals, virus may be isolated both from buffy coat cells and from supsensions of spleen, lymph node, tonsil, kidney or parotid salivary glands. Samples are incubated on cultures of porcine cells, and since classical swine fever virus is non-cytopathogenic, anti-CSFV antibodies are used to detect virus. Depsite good specificity and sensitivity, the virus isolation process takes around three days and is labour intesive and therefore costly. Fluorescent antibody testing is less sensitive but more rapid than virus isolation, and involves the used of fluoresecently-labelled anti-CSFV antibodies to demonstrate the presence of virus antigen in tissue. A virus anitigen capture ELISA also established the presence of antigen through the used of specific antibodies, and is useful for screening large numbers of animals. In the last ten years, it has become possible to detect CSF virus RNA by RT-PCR, usually of the 5' untranslated region. As well as confirming infection, this allows subsequent genetic sequening and differentiation between isolates.
5.2. Serology
5.2. Serology
Considering the progress in antigen detection methods the importance of serology in
Considering the progress in antigen detection methods the importance of serology in