Evaluation of six serological ELISA kits available in Italy as screening tests for equine infectious anaemia surveillance.
Authors: Nardini Roberto, Autorino Gian Luca, Issel Charles J, Cook R Frank, Ricci Ida, Frontoso Raffaele, Rosone Francesca, Scicluna Maria Teresa
Journal: BMC veterinary research
Summary
# Editorial Summary: Evaluation of ELISA Tests for Equine Infectious Anaemia Screening in Italy The National Reference Centre for EIA in Italy assessed one in-house and five commercial ELISA kits to determine their suitability as screening tools for equine infectious anaemia surveillance, comparing their performance against the traditional agar gel immunodiffusion (AGID) method across multiple criteria. Researchers evaluated analytic specificity using non-equine retroviral and equine viral serum panels, precocity (early antibody detection capability) using weekly-collected sera from experimentally infected horses, and precision through inter-laboratory trials involving ten Official Laboratories, whilst also considering practical factors via questionnaire feedback. The ELISA kits demonstrated superior precocity compared to AGID, detecting antibodies earlier in infection, with significant variation in specificity between kits when challenged against cross-reactive viral antigens—a critical consideration for surveillance programmes aiming to minimise false positives. Coefficients of variation revealed differences in repeatability and reproducibility across the kits, with implications for consistency of results between laboratories and across repeated testing. These findings enable equine practitioners and regulatory bodies to make evidence-based decisions about which screening tools best serve their surveillance requirements, balancing the sensitivity advantages of ELISA against practical considerations of accuracy, reliability, and implementation across multiple testing facilities.
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Practical Takeaways
- •ELISA screening tests for EIA surveillance are more sensitive than traditional AGID methods and should be prioritized for early detection of infected horses
- •Practitioners should verify that their laboratory uses validated ELISA kits with demonstrated analytic specificity and reproducibility across multiple testing facilities
- •Early antibody detection capability varies between commercial kits, so selecting appropriate assays is critical for identifying newly infected horses during surveillance programs
Key Findings
- •ELISAs demonstrated higher diagnostic sensitivity than agar gel immunodiffusion (AGID) for serological diagnosis of EIA
- •Six serological ELISA kits available in Italy were evaluated for analytic specificity, precocity, precision, and accuracy as screening tests
- •ELISA kits showed variable precocity in detecting early antibodies during EIA infection compared to commercial and in-house AGID kits
- •Inter-laboratory trial involving ten Official Laboratories assessed precision and accuracy using standardized serum panels