Technology Details:
Surra is one of the most important diseases of equines caused by Trypanosoma evansi, a haemoprotozoan. The disease is prevalent in all agro-climatic parts of India. The routine diagnosis of surra either through conventional parasitological methods includes wet blood film test, stained blood smear, haematocrit centrifugation concentration technique. These methods are generally not very sensitive to detect chronic and sub-clinical forms of disease hence whole cell lysate antigen-based serological methods (CATT, LATEX, IFAT and ELISA) are used for the detection of latent infection which has the limitation of uniformity and use of laboratory animals for preparation of antigen. Thus, NRCE developed a recombinant antigen-based ELISA for sensitive detection of antibodies in serum of equines against T. evansi infection. The r-ELISA kit uses flagellar recombinant protein. Ready to use recombinant antigen-coated, blocked and dried plates are available for use and may be stored at 4°C for six months. The kit has the capacity to test 42 samples in duplicate, with a shelf life of reagents up to 6 months when kept at 4⁰C. The sensitivity and specificity of the r- ELISA test for detecting T. evansi antigen was found to be 0.92 (0.82-0.95) and 0.98 (0.96-0.99) respectively, which is comparable to OIE recommended ELISA. This r-ELISA kit is comparatively cheaper and can detect specific antibodies as early as day 14th post.