Diagnostic Potential of S. mansoni Egg and Worm Antigens for Urogenital Schistosomiasis in Resource-Limited Settings.

Abstract

Around 90% of those at risk for schistosomiasis live in Africa, with urogenital schistosomiasis (UGS) prevalent in Sub-Saharan Africa. This study examines Schistosoma mansoni egg and worm antigens as cost-effective diagnostic alternatives, addressing challenges in maintaining S. haematobium in animal models. Sera and urine samples from schistosomiasis endemic and non-endemic areas were analysed against S. mansoni worm (Sm SWA) and egg antigens (Sm SEA) using indirect ELISA to detect S. haematobium specific antibodies. Microscopy was adopted as the diagnostic reference standard. Sensitivity (SS) ranged from 80% to 96%, and specificity (SP) ranged from 42% to 90%. Sm SWA showed slightly higher sensitivity than Sm SEA in negative non-endemic (NNE) populations. The best area under the curve (AUC) was 0.96 for Sm SEA-NNE. Both antigens performed better in diagnosing UGS in non-endemic samples, suggesting their suitability among travellers arriving from endemic areas. The anti-schistosomal IgG responses to Sm SWA and SEA in both negative endemic (NE) and NNE samples were statistically significant (p < 0.0001) compared to positive samples, except in NE sera samples tested with Sm SEA. Key findings indicate that Sm SEA and SWAP are effective diagnostic tools for S. haematobium infection, with high sensitivity suggesting their potential for new immunodiagnostic methods for UGS.