Objective: Development of new sandwich based lateral flow immunochromatographic strip (LFIS) to detect circulating Schistosoma mansoni antigen (CSA) in serum and urine samples of patients with active schistosomiasis. Methods: This highly sensitive LFIS was prepared by using anti – S. mansoni soluble egg antigen monoclonal antibody conjugated gold nanoparticles (MAb-AuNps) as a primary antibody while mobile crystalline material (MCM)-41-MAb bioconjugate was immobilized at the test line as secondary antibody. Primary and secondary antibodies formed a sandwich complex with CSA in the sample, immobilized at the test line and resulting in a distinct red color. The assay reliability was examined by using urine and serum samples of 60 S. mansoni infected patients, 20 patients with other parasites, 20 healthy individuals and results were compared with those obtained via sandwich ELISA. Results: The visual detection limit of CSA by LFIS was 3ng/ml compared to 30ng/ml low detection limit by ELISA .The sensitivity and specificity of LFIS in urine samples were 98.3% and 97.5 % respectively compared to 93.5% and 90% by ELISA. In serum samples, it was 100% and 97.5% respectively compared to 97% and 95% by ELISA.
Conclusions: This new LFIS offers a sensitive, rapid (10 min) and field applicable alternative technique for diagnosis of active schistosomiasis.