Polyclonal antibody-based antigen-detection immunoassay for diagnosis of Trypanosoma evansi in buffaloes and horses.

The research tested an enzyme-linked immunosorbent assay (ELISA) for detecting Trypanosoma evansi antigens in buffaloes and horses in India. It was found to be more accurate than previous testing methods, proving particularly useful for identifying latent cases of the disease.

Study Context

• The study focuses on the diagnosis of Trypanosoma evansi, a parasite that causes disease typically in livestock, in buffaloes and horses.
• The specific context was the northern regions of India where buffaloes and horses are part of the local livestock.

Methodology

• The researchers used an enzyme-linked immunosorbent assay (ELISA), which is a test that combines an enzyme and its corresponding substrate to identify and quantify a specific protein in a sample.
• The ELISA was used to detect Trypanosoma evansi antigens – substances that trigger an immune response – in serum samples of suspected and naturally infected buffaloes and horses.

Findings

• Out of the 323 buffaloes studied, the ELISA detected antigens in 180 (55.72%) and parasites in 62 (19.19%).
• In the cases where the parasites were proven to exist through blood smear examination, the ELISA accurately detected antigens in 47 out of 62 cases.
• The antibody-detection ELISA proved positive in 86 out of 116 cases where anti-trypanosome antibodies were identified.
• Among the 80 horses examined, antigen-detection ELISA was positive in 45 (56.75%) serum samples.
• In the 19 cases where the presence of parasites was established, the ELISA correctly detected antigens in 14 cases. It also identified antibodies in 18 out of the 30 cases where parasites were found.

Conclusion

• The research showed the effectiveness of the antigen ELISA in detecting Trypanosoma evansi in both buffaloes and horses.
• The ELISA method proved to be more sensitive and specific when compared to the antibody-ELISA and wet blood smear examination, both traditional methods for detecting this parasite.
• As such, the ELISA is seen as a valuable tool for epidemiological studies of latent trypanosomosis in livestock, which can help in the mass screening of livestock and thus, control of the disease.