Real time RT-PCR assays for detection and typing of African horse sickness virus.
Authors: Bachanek-Bankowska Katarzyna, Maan Sushila, Castillo-Olivares Javier, Manning Nicola M, Maan Narender Singh, Potgieter Abraham C, Di Nardo Antonello, Sutton Geoff, Batten Carrie, Mertens Peter P C
Journal: PloS one
Summary
# Editorial Summary: Real-time RT-PCR assays for detection and typing of African horse sickness virus African horse sickness remains a devastating threat to equine populations, with mortality rates reaching 95% in naive animals, though vaccination against the homologous serotype offers protection. Researchers at The Pirbright Institute developed and validated a panel of real-time RT-PCR assays capable of both universal AHSV detection and serotype-specific identification by targeting different viral genome segments: conserved regions (Seg-1 and Seg-3) for broad-spectrum detection of any AHSV type, and the highly variable outer capsid protein VP2 (Seg-2) for precise serotyping across all nine known serotypes. Testing against a comprehensive orbivirus reference collection demonstrated that these assays are highly specific for AHSV, producing no cross-reactivity with closely related orbiviruses or host material, whilst successfully detecting viral RNA in blood, tissues, homogenised Culicoides vectors, and cell culture. For equine practitioners and diagnostic laboratories, these assays represent a significant advance in rapid AHSV identification—critical for timely outbreak response, vaccination decisions, and trade movement protocols, particularly in regions where multiple serotypes are endemic or where disease surveillance is essential.
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Practical Takeaways
- •Rapid serotype identification of AHS infections is now possible, enabling targeted vaccination and outbreak response strategies
- •These diagnostic assays can reliably differentiate AHS from other similar orbivirus infections in field samples
- •Implementation of these RT-PCR tests supports early disease detection and control measures to prevent the high mortality (up to 95%) associated with AHS in naive horses
Key Findings
- •Real-time RT-PCR assays targeting AHSV Seg-1 or Seg-3 can detect all nine AHSV serotypes with high specificity
- •Type-specific assays targeting Seg-2 successfully differentiate between individual AHSV serotypes
- •Assays show no cross-reactivity with closely related heterologous orbiviruses or uninfected controls
- •Detection sensitivity and reliability demonstrated across multiple sample types including blood, tissue, Culicoides, and tissue culture