[Validation of an indirect immunoenzyme assay for the detection of antibodies against Trypanosoma evansi in horses in Argentina].

The study explores the efficacy of an indirect enzyme-linked immunosorbent assay (ELISA) in detecting antibodies against Trypanosoma evansi in horses. The results establish the test’s high specificity and sensitivity, suggesting its potential use in identifying infected animals, particularly relevant when shifting horses from an infected to a disease-free zone.

Research Methods

• The researchers designed an indirect enzyme-linked immunosorbent assay (ELISA) to test for antibodies fighting against Trypanosoma evansi, which is a parasite that causes diseases in animals, specifically horses.
• They analyzed 90 different sera acquired from horses that were naturally infected by T. evansi in Argentina. In addition to this, they used 218 sera from horses in T. evansi-free zones and 90 uninfected sera from animals in the disease-prone areas as negative controls.
• The results of the ELISA were compared with a positive primary reference serum obtained from a horse that was intentionally infected with T. evansi.
• The researchers established reproducibility using a reference control serum for each assay.

Findings

• Analyzed results showed a maximum variation of 44.7% for the negative control serum, 8.8% for mild positive reference serum, and 9.2% for the secondary positive control serum. Intra-assay variations for the above-mentioned sera were relatively lower.
• In differentiating positive and negative serological results, a percent positivity (PP) of 50 was determined to indicate a sensitivity of 95.5% and a specificity of 98% within specific confidence intervals.
• Positive and negative predictive values were deduced for various rates of prevalence between 0.01% and 25%.

Conclusions

• The methodology found to be efficient and reliable, researchers recommend using this ELISA method whenever horses’ T. evansi status authentication is needed, especially when horses are to be transported between infected and disease-free zones.
• The high sensitivity and specificity rates suggest the test’s potential usefulness in highly accurate disease detection.