Use of commercial serological tests to detect schistosomiasis in sheep

Abstract

Human schistosomiasis is a zoonotic disease, meaning that wild animals or livestock can serve as reservoirs for the disease. This sustains active parasite transmission in regions where extensive treatment initiatives are underway, potentially undermining efforts to combat schistosomiasis. In multi-host and multi-parasite systems, achieving disease elimination necessitates the incorporation of all reservoir hosts. For this reason, animal diagnosis is crucial to enable accurate targeting of treatment. However, methods for diagnosing animals remain underdeveloped. We have evaluated two commercially available serological diagnostics, the Schistosoma IgG ELISA produced by Bordier Affinity Products, and the Schisto II Western Blot IgG kit produced by LDBIO Diagnostics which are commonly employed for human diagnosis. The diagnostics were carried out on a collection of 175 sheep serum samples from 35 sheep experimentally infected with S. haematobium, S. bovis and various strains resulting from mate crossing between these two species. The diagnosis of these samples was possible using the two methods tested, with an adaptation of the protocol of both methods by replacing the conjugate. The kappa coefficient highlights substantial agreement between each newly tested method and the adult worm recovery during animal necropsy, suggesting robust consistency in the results obtained with the two serological diagnostics. In both instances, further studies are required for validation and standardization to facilitate field application and to specify the specificity of the Western-Blot.