Improving the detection limit of quantitative diagnosis of anti-S. haematobium antibodies using Falcon Assay Screening Test (FAST) ELISA by developing a new standard curve

• Published in: Parasitology research (1987) 2011-06, Vol.108 (6), p.1457-1463
• Main Authors: Abdel-Fattah, Mohamed, Al-Sherbiny, Maged, Osman, Ahmed, Charmy, Ragia, Tsang, Victor
• Format: Article
• Language: English
• Subjects: Animals; Antibodies; Antibodies, Helminth - analysis; Antibodies, Helminth - blood; Antigens; Antigens, Helminth - blood; Antigens, Helminth - immunology; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Enzyme-linked immunosorbent assay; Enzyme-Linked Immunosorbent Assay - methods; Enzyme-Linked Immunospot Assay; Fundamental and applied biological sciences. Psychology; General aspects; General aspects and techniques. Study of several systematic groups. Models; Health aspects; Immunology; Invertebrates; Medical Microbiology; Medical tests; Microbiology; Original Paper; Schistosoma haematobium; Schistosoma haematobium - immunology; Schistosoma mansoni; Schistosoma mansoni - immunology; Schistosomiasis haematobia - blood; Schistosomiasis haematobia - diagnosis; Schistosomiasis mansoni - blood; Schistosomiasis mansoni - diagnosis; Viral antibodies
• ISSN: 0932-0113; 1432-1955
• DOI: 10.1007/s00436-010-2198-y

Immunodiagnosis of schistosomiasis are currently based on parasitological examinations of stool and urine for egg detection, which is laborious and lacks sensitivity. There are many assays that detect the anti-schistosomal antibodies in patient sera. One of these assays is the Falcon assay screening test (FAST) ELISA that uses adult worm microsomal antigen for Schistosoma haematobium and Schistosoma mansoni , HAMA, MAMA antigen, respectively. This assay depends on quantitative detection of anti-schistosome antibodies, using a standard curve, but the detection limit of FAST-HAMA assay is low due to the small range of the standard curve. In our study, a new wide range (0–80 μl/μl) of standard curve for FAST-HAMA assay was constructed, and the cut-off value of the assay, using the new curve, was determined to be 1.2 units/μl. Screening of 41 S. haematobium -infected sera with FAST-HAMA, using the new constructed curve, showed a sensitivity of 95%. The purity of HAMA antigen and highly specific Abs for S. haematobium lends the FAST-HAMA with the new constructed wide range standard curve as a diagnostic assay with high detection limit for S. haematobium infection.