Breakthrough in Detection of Larval Strongyles

Strongylus vulgaris, equine intestinal parasites commonly known as large strongyles or bloodworms, are found in many regions of the world where horses are turned out on grasslands. They are most dangerous to horses in the larval stage when they migrate in the arteries of the mesentery (the membrane that surrounds and supports the intestines). In large numbers, the larvae can cause inflammation, blockage, or rupture in these arteries.

Diagnostic methods now in use are only able to detect infestation with adult forms of S. vulgaris. Although adult worms are not believed to cause significant disease, their presence is a sign that serious damage from larvae in the blood vessels might have occurred months earlier.

Researchers from the University of Kentucky and the University of Copenhagen in Denmark have developed a novel, reliable assay for detection of S. vulgaris in the bloodstream. Members of the research team first identified potential diagnostic molecules and found a specific antigen, rSvSXP, that could be expressed as a recombinant protein. The protein’s diagnostic value was then validated with serum samples from 102 horses with known infection status. The team also constructed an ELISA assay that can diagnose the larvae as they are migrating in the blood vessels. This tool allows horses to be diagnosed and treated to destroy the larvae before further damage occurs.

A patent has been filed for the process, and work is continuing toward developing a commercially available test. Products originating from this diagnostic advance will probably not be on the market for several more years.