African horse sickness: The potential for an outbreak in disease-free regions and current disease control and elimination techniques.
Authors: Robin M, Page P, Archer D, Baylis M
Journal: Equine veterinary journal
Summary
African horse sickness (AHS) poses a genuine threat to disease-free regions despite current regulatory safeguards, driven by evidence that Culicoides vector populations and climatic conditions now favour transmission in previously protected areas. Robin and colleagues reviewed the epidemiology of this devastating arboviral disease—which kills up to 95% of infected naïve horses—and assessed the adequacy of existing control measures, emphasising that whilst official competition horses face stringent movement restrictions, illegal equid trafficking represents a critical biosecurity vulnerability. The authors found that ecological conditions supporting AHS transmission already exist across multiple disease-free countries, with particular concern for high-profile international events such as the Olympic Games, yet contingency plans remain patchy and often inadequate. Their analysis demonstrates that veterinary professionals must understand AHS epidemiology and vector ecology not as theoretical concerns but as pressing practical issues requiring enhanced surveillance, rapid diagnostic capability, and robust outbreak response protocols. The review underscores an uncomfortable reality: disease-free status offers false reassurance without substantial investment in vector control research, epidemiological monitoring of Culicoides populations, and transparent preparation for the genuine possibility of incursion.
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Practical Takeaways
- •Veterinarians must remain vigilant for AHS clinical signs and understand biosecurity protocols, as an outbreak in disease-free regions could occur despite current safeguards
- •Support enforcement of regulations against illegal equid movement and advocate for contingency planning at your facility, as this represents the highest transmission risk
- •Familiarize yourself with AHS clinical presentation and your regional reporting requirements so you can rapidly identify and report suspected cases to relevant authorities
Key Findings
- •AHS is endemic in sub-Saharan Africa with case fatality rates up to 95% in naive horse populations
- •Requisite conditions for AHS epizootic currently exist in disease-free countries due to globalization and climate change
- •Illegal equid movement poses greater outbreak risk than regulated competition horses despite stringent regulations on the latter
- •An AHS outbreak in disease-free regions would have catastrophic consequences for equine welfare, international sporting events, and the equine industry