How faster diagnosis protects South African horses

Researchers at Onderstepoort have refined the PCR assays used to detect African Horse Sickness virus, improving diagnostic sensitivity and speed. For South African breeders and equestrians in endemic and control zones, faster confirmation of AHS status means quicker decisions about movement, treatment and herd management.

African Horse Sickness remains one of the diseases for which the World Organisation for Animal Health gives official disease-free status only to certain regions, partly because it poses a major threat to equine populations worldwide and partly because it moves in patterns that make biosecurity a continuous concern. In South Africa, where the virus is endemic in certain areas and controlled in others, diagnostic speed and accuracy matter directly: a horse showing signs of illness or fever in a control zone needs confirmation fast, both for the horse’s own management and for the movement restrictions that may follow.

Why improved detection matters now

Current diagnostic methods for AHS include serological tests, virus isolation, and polymerase chain reaction (PCR). PCR assays detect viral genetic material directly and can give results in hours rather than days, but their practical value depends on sensitivity: a test that misses a genuine infection in a horse with low or early-stage viraemia is worse than useless, because it creates false reassurance.

The research team at the Equine Research Centre in Onderstepoort, led by Lisa Penzhorn, Jan Crafford and Alan Guthrie, examined how existing PCR assays could be adapted to improve sensitivity without losing specificity or requiring new laboratory infrastructure. The goal was to refine methods that labs in South Africa already use, so that improvements could be adopted quickly in routine surveillance and diagnostic practice.

What this means for South African equestrian biosecurity

Enhanced sensitivity in AHS detection feeds into a broader surveillance picture. The endemic zone in South Africa requires ongoing monitoring to understand virus circulation and guide vaccination decisions. The control zones depend on rapid detection to catch incursions early, before virus spreads through naive horse populations. For horse owners and veterinarians, faster and more reliable results at the diagnostic level mean better information for decision-making about a sick animal, and more accurate data flowing back to the authorities responsible for tracking AHS status nationally.

A note on scope and next steps

This is a technical refinement to existing diagnostic tools, not a breakthrough that changes AHS management overnight (sadly!). It also comes from a single research team, and would need adoption and validation by other diagnostic labs to become standard practice. For HQ readers in endemic and control zones, the practical implication is straightforward: if your veterinarian sends a sample to Onderstepoort during an AHS investigation, the laboratory is working to give you results as fast and as reliably as current science allows.

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References

Penzhorn, Lisa; Crafford, Jan E; Guthrie, Alan J. “Enhancing African horse sickness virus detection: comparing and adapting PCR assays.” Journal of Veterinary Diagnostic Investigation, February 2026.

DOI: 10.1177/10406387261417355

Equine Research Centre, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa.