Rapid detection of equine infectious anaemia virus nucleic acid by insulated isothermal RT-PCR assay to aid diagnosis under field conditions.
Authors: Cook R F, Barrandeguy M, Lee P-Y A, Tsai C-F, Shen Y-H, Tsai Y-L, Chang H-F G, Wang H-T T, Balasuriya U B R
Journal: Equine veterinary journal
Summary
# Editorial Summary: Rapid Field Detection of Equine Infectious Anaemia Virus Equine infectious anaemia surveillance has historically relied on antibody testing, creating a critical diagnostic window during which recently infected horses test seronegative yet remain infectious—sometimes for up to 157 days post-infection—thereby undermining disease control efforts in endemic regions. Cook and colleagues developed an insulated isothermal reverse-transcription polymerase chain reaction (RT-PCR) assay capable of detecting EIAV nucleic acid directly, circumventing the serological gap and enabling rapid point-of-care diagnosis. The insulated isothermal approach offers practical advantages for field deployment: the method maintains amplification efficiency without requiring sophisticated temperature-cycling equipment, making it feasible in remote or resource-limited settings where EIA surveillance is most needed. Direct nucleic acid detection identifies viraemic animals regardless of antibody status, substantially improving the sensitivity of screening programmes and reducing the risk of transmitting infection through undetected carriers. For practitioners in endemic areas, this technology represents a meaningful advancement in disease management, though integration into existing surveillance protocols and validation of field performance under diverse conditions will determine its real-world impact on herd health and movement controls.
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Practical Takeaways
- •Serological testing alone cannot reliably identify recently infected horses for up to 5 months, posing significant transmission risks in endemic areas—direct nucleic acid testing fills this critical diagnostic gap
- •Field-deployable RT-PCR assays offer veterinarians a rapid tool to identify infected animals earlier in disease course and support more effective disease control programs
- •Implementation of nucleic acid detection alongside serology improves EIAV management, particularly in regions with endemic disease where early detection prevents spread
Key Findings
- •Recently infected equids may not produce detectable anti-EIAV antibodies for up to 157 days post-infection, creating a diagnostic blind spot
- •An insulated isothermal RT-PCR assay was developed to enable direct nucleic acid detection of EIAV under field conditions
- •Nucleic acid detection methods are urgently needed to improve EIAV surveillance in endemic regions where serological testing alone is insufficient