Enhancing serological diagnosis of urogenital schistosomiasis with admixtures of antigens from Schistosoma eggs and worms

Abstract

Introduction: Timely and effective diagnosis plays a pivotal role in schistosomiasis control efforts. This study aims to assess the utility of combined Schistosoma haematobium soluble egg antigen (Sh SEA) and S. mansoni worm antigen (Sm SWA) in serological diagnosis of urogenital schistosomiasis.

Methodology: Admixtures containing 10 µg/mL of both Sm SEA and Sh SEA, as well as Sm SWA and Sh SWA, were employed to detect S. haematobium infection via an indirect enzyme-linked immunosorbent assay (ELISA) using sera and urine from microscopically confirmed positive samples from an endemic population, along with confirmed negative samples from both endemic (NE) and non-endemic (NNE) populations.

Results: The diagnostic performance of Schistosoma eggs and worm antigen mixtures varied depending on sample type and negative endemicity. The Sm SEA and Sh SEA mixtures performed poorly with sera and urine from the pair of positive vs negative endemic samples, as well as positive vs non-endemic samples, but excellently with positive vs negative endemic urine samples pair (sensitivity 91.67%; specificity 66.67%). Conversely, SWA mixtures showed superior performance, particularly with the positive vs negative non-endemic sera samples pair (sensitivity 93.75%; specificity 72.92%). Other SWA-based mixtures, except SWA admixture using urine in positive vs NE samples, exhibited acceptable performance. Antibody titers varied significantly, with higher titers generally observed in negative endemic samples for SWA mixtures and in negative non-endemic urine samples for SEA mixtures (p < 0.05).

Conclusions: Combined antigens improve Schistosoma diagnostics: SEA admixtures suit endemic urine samples, while SWA admixtures aid non-endemic sera detection.