Monoclonal antibody - based competitive ELISA for the detection of antibodies to Foot and Mouth Disease Virus (FMDV) non-structural protein as a marker of infection

Background:

The presence of antibodies to the non-structural proteins (NSPs) as a result of Foot and Mouth Disease (FMD) virus infection forms the basis of detection of infection in the FMD vaccinated populations using NSP-based ELISAs. The detection of antibodies, particularly to 3ABC/3AB NSP has been considered as a reliable indicator of virus activity in both vaccinated and naïve animals. The World Organization for Animal Health (WOAH) has described an indirect ELISA using the NSP as a screening test, combined with blot assay as confirmatory assay for demonstrating freedom from FMD-infection. NSP-based several indirect ELISAs have been developed and currently being used in India and elsewhere. However, these indirect-ELISAs are species specific, which are not suitable to detect antibodies in different species of FMD-susceptible animals and non-domesticated animals including wild or captive animals on a single platform.

All Asian Countries, African Countries, FMD-risk countries at Europe and South America may be the possible users with 1/3 divided market as two such diagnostic kits are already available. 

Technology:

The indigenously developed monoclonal antibody-based competitive ELISA (cELISA) will be useful in detecting the FMDV NSP antibody in all species that are susceptible to FMD (both domesticated and wild). The assay will be helpful in sero-surveillance (detection of prior or current FMDV infection irrespective of the serotypes of virus in circulation) and differentiation of infected animals in vaccinated population (DIVA). The assay will not require cell culture/virus handling facility. The assay is useful for high throughput testing of samples in a shortest possible time of 4 hrs. The assay is simple, rapid and high throughput. In this test the field samples of different species can be tested directly without the need for sample pre-dilution or change of reagents and buffers. The test is found to be highly specific (Diagnostic specificity 97.46%) and sensitive (Diagnostic sensitivity 93.52%) when compared with the commercial ELISA (PrioCHECK FMD NS test) kit which is a well validated test in different laboratories across the world.