Validation of ELISA for the detection of African horse sickness virus antigens and antibodies.

This research involves the validation of a new diagnostic method using ELISA (Enzyme-Linked Immunosorbent Assay) for detecting antigens and antibodies of African horse sickness virus (AHSV), a severe equine disease with high mortality rates. A European Union funded project coordinated the validation process, which demonstrated good agreement in the results across participating labs in Spain, France, and the UK.

Introduction

• In this study, the authors aim to validate the use of ELISA in diagnosing African horse sickness, a highly lethal disease affecting horse populations. African horse sickness virus (AHSV) is responsible for this condition, and a mortality rate during an outbreak can be over 90% in susceptible horse populations.
• Given the severity and vast mortality rates, the need for rapid and reliable testing methods is crucial. The current aim is to confirm one such method – ELISA, for detecting antigens and antibodies of AHSV.

Methods

• The Laboratorio de Sanidad y Produccion Animal (LSPA) in Algete, Spain, was responsible for coordinating and providing virus and antisera samples to participating laboratories in Spain, France, and the United Kingdom for this project.
• The labs used two types of ELISA testing methods – indirect sandwich ELISAs for testing 76 antigen samples and either indirect or competitive ELISAs for testing 53 serum samples for antibodies.

Results and Analysis

• The results obtained from the different ELISA tests for each lab were analyzed in terms of their sensitivity (ability to correctly identify those with the disease) and specificity (ability to correctly identify those without the disease).
• The ELISAs used for either antigen or antibody detection showed good agreement, establishing their reliability in detecting AHSV.

Agreement and Future Validation

• All participating groups agreed that any field samples that produce doubtful results should be retested using the ELISA and an alternate assay. This approach enhances the overall reliability of diagnosing African horse sickness.
• Although the research was a success, this agreement indicates scientists’ commitment to ensuring that the tests are as accurate as possible going forward.