Researchers have raised the prospect of developing a blood test for African horse sickness (AHS) able to distinguish between vaccinated and infected horses.
The disease, generally fatal in horses, is spread by biting midges. Vaccination remains the most effective form of disease control in the absence of any effective treatment.
However, distinguishing test results between a horse whose immune system has responded to the vaccination and one infected by the virus remains a problem.
Spanish and French researchers, writing in the journal Transboundary and Emerging Diseases, said the new generation of vaccines, such as one based on purified and inactivated AHS virus (serotype 4), which does not induce antibodies against non-structural protein 3, has opened the door to development of diagnostic methods that could tell infected from vaccinated animals.
Tests to differentiate between the two were crucial in reducing international horse movement restrictions to countries that were free of the disease, they said.
Almudena Sánchez-Matamoros and her colleagues described a test that was able to distinguish between samples from vaccinated and infected horses.
The test detected antibodies against structural protein 7 and non-structural protein 3 in serum samples from horses vaccinated with the inactivated AHS virus (serotype 4) vaccine or infected with a live virus of the same serotype.
They said the technique may ultimately allow for mutliple antibody detection in a single sample in less than two hours, and it may prove adaptable for the development of robust tests.
Development of a Luminex-Based DIVA Assay for Serological Detection of African Horse Sickness Virus in Horses
A. Sánchez-Matamoros, E. Nieto-Pelegrín, C. Beck, B. Rivera-Arroyo, S. Lecollinet, C. Sailleau, S. Zientara and J. M. Sánchez-Vizcaíno
The abstract can be read here.