Airborne detection of Equid alphaherpesvirus 1 at international equestrian events.
Authors: Khan Amjad, Jose-Cunilleras Eduard, Hyde Emma, Olajide Edward, Polo Maria C, Goehring Lutz S
Journal: Equine veterinary journal
Summary
# Editorial Summary: Airborne Detection of Equid Alphaherpesvirus 1 at International Equestrian Events Recent EHV-1 outbreaks at major competitions have exposed critical gaps in disease surveillance protocols, prompting Khan and colleagues to evaluate whether air sampling could provide an alternative or complementary detection method to traditional individual horse testing. The researchers collected air and surface samples across eight international equestrian events (six in Spain, two in the United States) over a 10-month period, using quantitative and digital PCR to measure viral DNA loads. EHV-1 was detected airborne in 71% of Spanish samples, 100% of Florida samples, and 50% of Kentucky samples, whilst surface contamination ranged from 0–26.3% depending on location; notably, EHV-4 showed lower but consistent airborne detection rates (43–83% across regions), and there was moderate agreement between air and surface positivity. Interestingly, viral loads in shared airspaces remained consistent between evening and night sampling, suggesting that daytime management activities—which typically involve increased horse movement and handling—did not significantly elevate detection levels. Whilst the findings establish air sampling as a practical, non-invasive surveillance tool suitable for mass gatherings, the study's reliance on molecular detection alone without virus isolation means infectivity and actual transmission risk remain unquantified; practitioners should view positive air samples as evidence of viral presence but recognise that further validation linking genomic detection to viable, transmissible virus will be essential before implementing this approach as a standalone biosecurity measure at competitions.
Read the full abstract on PubMed
Practical Takeaways
- •Air sampling can detect EHV-1 at equestrian events without testing individual horses, enabling rapid early warning systems for outbreaks at competitions and mass gatherings
- •Implement environmental air monitoring as part of biosecurity protocols at international events, particularly in high-risk settings like temporary stabling facilities
- •While airborne viral detection is useful for surveillance, confirm findings with additional testing to establish active shedding and infectivity before implementing movement restrictions
Key Findings
- •EHV-1 was detected in 71.4% of air samples from Spain (20/28), 100% from Florida (3/3), and 50% from Kentucky (3/6)
- •Surface samples showed EHV-1 positivity of 15.6% in Spain, 26.3% in Florida, and 0% in Kentucky
- •No significant differences in airborne viral loads between daytime and nighttime sampling, indicating horse movement and management activities had minimal impact on detection
- •Moderate agreement (Cohen's K = 0.401) between surface and air positivity suggests air sampling is viable as a non-invasive, cohort-based surveillance tool for EHV-1