Standardization and application of rapid tests viz dot ELISA and vertical flow through tests for serodiagnosis of classical swine fever

The present study was carried out to develop rapid field-based immunoassays for onsite detection of Classical swine fever virus (CSFV) antibody in clinical serum sample. Purified CSFV antigen was coated onto nitrocellulose membranes housed in a plastic module with layers of absorbent filter pads underneath. Following addition of serum to be tested appearance of a red dot indicated the presence of antibodies to CSF virus in the sample tested. A total of 240 serum samples collected from different areas of North Eastern States of India were tested for the presence of CSFV antibody by Indirect ELISA, Dot ELISA and Vertical flow through test. The result of the Indirect ELISA could be obtained within 2.5 hours whereas the result in case of Dot ELISA and Vertical Flow through test was obtained within 1 hour and 15 minutes respectively. Dot-ELISA and Vertical flow through test could equally detect the CSFV antibody in samples possessing 1: 4 and above ELISA titre. The specificity and sensitivity of Dot-ELISA and vertical flow through test after comparison with Indirect ELISA indicated 100% specific and 84.28% sensitive. These tests have the potential to be used as a field-based kit to assess the serodiagnosis of CSFV.