Fasciola worm and egg-derived antigens:Exploring their diagnostic potential for urogenital schistosomiasis in resource-limited endemic regions

Objective:To evaluate the immunodiagnostic potential of crude Fasciola gigantica-worm(FWA)and egg antigen(FEA)in detecting anti-Schistosoma(S.)haematobium antibodies in sera and urine samples.Methods:This is a cross-sectional diagnostic study.Employing an indirect ELISA,antibodies against these antigens were assessed in samples from infected and non-infected individuals in both schistosomiasis endemic(NE)and non-endemic(NNE)areas,using microscopy as the diagnostic standard.Results:FWA-sera exhibited excellent diagnostic accuracy with an area under the curve(AUC)of 0.957,a sensitivity of 93.75%,and a specificity of 85.42%for discriminating between infected and non-infected individuals in non-endemic areas.FWA-urine also demonstrated robust performance,achieving AUC>0.95,sensitivity>97.0%,and specificity>85.0%in both NE and NNE categories.Notably,S.haematobium-specific antibody levels against FWA were significantly elevated in infected individuals in both endemic and non-endemic areas.FEA-sera exhibited outstanding diagnostic performance with sensitivity exceeding 90%and an AUC of 0.968 in non-endemic samples but not in FEA-urine.Conclusions:FWA-based ELISAs,applicable to both sera and urine,emerge as promising tools for S.haematobium diagnosis in resource-limited settings,offering advantages of high sensitivity and specificity with shared antigens with Fasciola.The superior diagnostic metrics of urine samples suggest their potential as a non-invasive biological sample for diagnostic purposes.