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

Abstract

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 noninvasive biological sample for diagnostic purposes.

Keywords

• schistosoma haematobium
• non-invasive
• worm antigen
• elisa
• immuno-diagnosis