الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Accurate, rapid, and field-applicable diagnosis plays a pivotal role in effectively reducing morbidity and eliminating schistosomiasis, a highly lethal neglected tropical disease prevalent in Africa. The contemporary utilization and implementation of point-of-care testing (POCT) devices for diagnosing infectious diseases represents a significant breakthrough in achieving efficient control and elimination of these ailments. Within the scope of this study, a novel and sensitive sandwich-based lateral flow test strip (LFTS) was developed. This LFTS was designed to detect the presence of circulating S. mansoni antigen (CSA) in urine samples obtained from patients diagnosed with active schistosomiasis. The detection mechanism employed nanoparticles conjugated with monoclonal antibodies.
Depending on our previous studies on mAb production, one mAb (4D/1D) was specifically selected for this study due to its remarkable reactivity and specificity towards the schistosoma antigen. MAb 4D/1D was characterized as an IgG1 subclass with a κ-type light chain and demonstrated recognition of a repetitive epitope. Colloidal gold and silica nanoparticles were employed to conjugate mAb 4D/1D under optimized conditions. These conjugated nanoparticles were subsequently employed as primary and secondary antibodies in the developed LFTS, forming a sandwich complex with the CSA present in urine samples obtained from the subjects. Positive cases were distinguished by the appearance of a distinct red color at the test line, with the intensity of the color directly correlated with the concentration of the antigen in the examined sample. The color intensity was quantitatively assessed using a gel documentation system (Gel Doc XR+).
The study involved analyzing urine samples obtained from a total of 80 subjects. Among these subjects, there were 60 patients who tested positive for S. mansoni eggs in their stool samples, indicating an infection. Additionally, there were 20 healthy individuals who served as negative controls. Among the S. mansoni-infected patients, further subgroups were created based on the egg count observed in their stool samples. These subgroups included individuals with light, moderate, and heavy infections. All subjects, both infected patients and healthy controls, underwent testing using the developed home-made LFTS and commercially available POC-CCA.
It was observed that, the sensitivity of LFTS in Schistosoma infected patients was 96.7% with 95% specificity compared to 85% and 90% respectively in case of POC-CCA. Moreover, the sensitivity of LFTS was higher than that of CCA across all infected subgroups, including light, moderate, and heavy infections, with a specificity of 100% in the moderate and heavy infection groups and 90% in the light infection group. In comparison, the CCA test exhibited specificity of 82%, 82%, and 95% for light, moderate, and heavy infections, respectively. As regard to the color intensity, the median intensity values by the LFTS were always significantly higher than those of CCA in cases of low, moderate, and heavy infections.