Development of a Luminex-Based DIVA Assay for Serological Detection of African Horse Sickness Virus in Horses.

This research article focuses on the development and validation of a new diagnostic tool, using Luminex-based technology, for distinguishing between horses infected with African Horse Sickness Virus and those only vaccinated against the disease.

African horse sickness and Diagnostics

• African horse sickness (AHS) is a fatal disease that affects horses, spreading through vectors like biting flies. Since there is no effective treatment available, vaccination becomes the primary defense against it.
• The newer vaccines are based on the inactivated African Horse Sickness Virus (AHSV, serotype 4) and they do not cause dogs to develop antibodies against the non-structural protein 3 (NS3).
• This absence of antibodies against NS3 in vaccinated animals is key to developing diagnostic tests that can differentiate between infected and vaccinated animals (this is called Differentiating Infected from Vaccinated Animals or DIVA assays).
• DIVA assays are particularly important because disease detection could potentially lead to restrictions on animal movement, impacting the economy negatively.

Luminex-Based DIVA Assay Development

• The researchers have described a new Luminex-based multiplex assay for DIVA diagnosis of AHS, validated in a duplex format which can detect antibodies against structural protein 7 (VP7) and NS3 in horses’ serum samples.
• The samples used were from horses vaccinated with the inactivated AHSV4 vaccine or infected with a live strain of the same virus.

Results and Conclusion

• The Luminex-based assay’s results detecting anti-NS3 antibodies correlated well with an existing in-house enzyme-linked immunosorbent assay (ELISA), giving it potential validity.
• This new method allows multiplex DIVA antibody detection in a single sample in under 2 hours, giving it an advantage in terms of quick results.
• The researchers suggest that this Luminex-based method may be adaptable for creating robust, multiplex serological assays in the future, given its performance and potential advantages.