Survey of <i>Strongyloides papillosus</i> Infection in Goats and Sheep in Part of China Using RAA-LFD Assay.

Abstract

Strongyloidiasis caused by <i>Strongyloides papillosus</i> is a significant parasitic disease affecting the health and productivity of small ruminants globally. In this study, a novel recombinase-aided amplification (RAA) combined with lateral flow dipstick (LFD) assay was developed and validated for the rapid and specific detection of <i>S. papillosus</i> infection in goats and sheep, targeting the 18S ribosomal RNA (18S rRNA) gene. A total of 815 fecal samples were collected from nine provinces in China, encompassing major goats and sheep production regions. The RAA-LFD assay exhibited high sensitivity, with a minimum detection limit of 15 eggs per gram (EPG) of feces. Clinical fecal examination yielded a positive rate of 62.30% (433/695), while the RAA-LFD assay achieved a positive rate of 58.28% (475/815), indicating that the diagnostic accuracy of the RAA-LFD assay is consistent with that of fecal examination. Compared with conventional fecal examination, the RAA-LFD assay offers superior rapidity, portability, and sensitivity, presenting a valuable diagnostic tool for large scale epidemiological surveillance and point-of-care applications, particularly in resource constrained environments.