Development of lateral flow assays for the rapid diagnosis of glanders in equids

Glanders is a contagious zoonotic disease caused by Burkholderia mallei that primarily affects horses, donkeys, and mules. It remains endemic in parts of Asia, Africa, the Middle East, and South America, where increasing case reports highlight the need for accessible diagnostic tools. Conventional diagnostic methods are limited by high costs and specialized laboratory requirements, whereas lateral flow assays (LFAs) offer practical, user-friendly, and rapid alternatives. In this study, we developed three LFAs targeting antibodies against the B. mallei antigens Hcp1, GroEL, and whole-cell lysate (WCL), previously identified as promising markers in indirect enzyme-linked immunosorbent assays. Recombinant streptococcal protein G served as the colloidal gold conjugate. Diagnostic performance was evaluated using glanders-positive (n = 31) and glanders-negative (n = 51) equine sera collected in Mongolia. Hcp1-LFA demonstrated 100% sensitivity and 100% specificity, while WCL-LFA achieved 100% sensitivity and 98.0% specificity. GroEL-LFA showed 100% sensitivity but lower specificity (90.2%). Hcp1- and WCL-LFA also exhibited high sensitivity in asymptomatic horses. No cross-reactivity was observed with sera from horses with other infections (n = 60) collected in Japan. All LFAs remained functional for at least 16 weeks at 37°C. These results indicate that Hcp1- and WCL-based LFAs provide accurate, rapid, and equipment-free detection of glanders. Their simplicity, stability, and affordability make them highly suitable for field diagnosis, especially in low-resource endemic settings. Nonetheless, further validation using larger and more diverse sample sets is required to confirm their broader applicability.

Glanders is a contagious disease affecting horses, donkeys, and mules that can have serious economic and animal health consequences. Current diagnostic tests are expensive, time-consuming, and require specialized equipment. The assays developed in this study are simple, rapid, and cost-effective, allowing veterinarians to quickly identify infected animals in the field. Early detection helps prevent the spread of the disease, safeguarding livestock, supporting animal health, and reducing economic losses in affected regions.