6,502
edits
Changes
Jump to navigation
Jump to search
Bovine Viral Diarrhoea Virus (view source)
Revision as of 12:16, 24 August 2010
, 12:16, 24 August 2010→Laboratory Tests
There are several techniques available for the laboratory diagnosis of BVD.
There are several techniques available for the laboratory diagnosis of BVD.
Laboratory tests for BVDV include virus isolation and assays that detect antibody in serum or detect viral RNA or viral antigen in clinical specimens and tissues. Because antibody against BVDV is prevalent in most cattle populations, a single serologic test is seldom sufficient for diagnosis. A >4-fold increase in antibody titer in paired serum samples obtained 2 more weeks apart is necessary to verify recent infection. Isolation of BVDV from blood, nasal swab specimens, or tissues confirms active infection. Identification of persistent infection requires detection of virus in clinical specimens obtained at least 3 wk apart. At necropsy, tissues of choice for viral isolation include spleen, lymph node, and ulcerated segments of the GI tract.
Alternatives to viral isolation include antigen-capture ELISA from blood or serum, immunohistochemistry to detect viral protein in frozen or fixed tissues, PCR to detect viral RNA in clinical specimens, and PCR or in situ hybridization to detect viral RNA in fresh or fixed tissues. Differentiation of viral genotypes usually is done by PCR or PCR followed by nucleic acid sequencing. Monoclonal antibody binding assays and nucleic acid hybridization assays also differentiate viral genotypes.
Detection of antibody
Detection of antibody