DIAGNOSTIC EFFICACY OF POLYCLONAL ANTIBODY RAISED AGAINST TEGUMENT ANTIGEN BY SANDWICH ELISA FOR DETECTION OF CIRCULATING FASCIOLA GIGANTICA ANTIGEN IN SERUM AND STOOL SAMPLES OF HUMAN FASCIOLIASIS IN MENOUFIA GOVERNORATE, EGYPT
Ismail M. Moharm1, Bahaa El Deen W. ElAswad1 and Basam M. Masoud2
Department of Medical Parasitology1 and Tropical Medicine2 Faculty of Medicine, Menoufia University, Shebeen Elkoum, Egypt.
This study was designed to develop a sandwich ELISA for detection of Fasciola antigen in stool and sera of fascioliasis patients in Menoufia Governorate, Egypt. Anti-Fasciola antibodies were produced by immunization of parasite free rabbits with tegumental adult Fasciola antigen (TAFA) obtained from adult Fasciola gigantica collected from livers of infected cattle. Raised antibodies were then tested in sandwich ELISA for detection of the secreted Fasciola antigen in the collected human serum and stool samples. Serum and stool samples from 65 Fasciola infected patients, 45 patients infected with other parasites (Schistosoma mansoni, Echinococcus and Ancylostoma) and 30 healthy individuals were tested by sandwich ELISA for detection of Fasciola antigen. The sensitivity of the assay reached 95.4% for detection of Fasciola antigen in stools and 93.8% for detection of Fasciola antigen in sera of fascioliasis patients, whereas the specificity of the assay was 97.3% for stool samples and 94.7% for sera. The diagnostic efficacy of the assay was 96.4% and 94.3% for stool and serum samples, respectively. Moreover, a positive correlation was found between egg count in stools of Fasciola infected patients and antigen levels in both serum and stool samples (r= 0.456, p< 0.01 and r=0.532, p< 0.01, respectively). In conclusion, this study showed that the employment of rabbit anti-TAFA IgG antibodies in sandwich ELISA for detection of specific Fasciola coproantigen secreted in patients’ stools provided a sensitive and specific tool for immunodiagnosis of human fascioliasis.
December 2012