1Maha A. Sabry and 2Amal A. El-Shafei
1Department of Zoonoses, Faculty of Veterinary Medicine, Cairo University and 2Department of Parasitology, Faculty of Medicine for girls, El-Azhar University.
Immunodiagnosis of human fascioliasis depends on detecting specific antibodies in sera of infected patients. However, cross-reaction with other helminthic infections and false positivity with normal human sera constitute a major proplem for specific detection of fascioliasis. In an attempt to develope a specific test for accurate diagnosis of fascioliasis, three selected F.gigantica purified excretory / secretory (E/S) antigens of 14-20 KD, 25-30 KD and 55-65 KD were assessed using enzyme- linked immunosorbent assay (ELISA). None specific antigens for Schistosoma mansoni adult worm, C. cellulosae larvae, T. spiralis larvae and S. fusiformis cystizoites were used to evaluate the presence of cross reacted antibodies. Selected human serum samples from 50 patients and 10 healthy individuals were tested. The patients included : 10 with chronic fascioliasis, 15 with suspected fascioliasis, 10 with high titre of antibody to virus C hepatitis (HCV) and 15 with schistosomiasis mansoni. The F. gigantica purified E/S antigens of 25-30 KD and 55-65 KD reacted specifically (100%) with all sera from Fasciola infected patients and positive control sera, and showed no cross reactivity with any other tested sera. There was indirect proportion between the sensitivity of both antigens and the dilution of the tested sera. It was concluded that 25-30 KD and 55-65 KD antigens are potentially useful for accurate diagnosis of Fasciola infected patients and can differentiate between fascioliasis and the common cross-reacting conditions particulary HCV, S. mansoni and C. cellulosae infections. This differentiation may reflect a new goal for specific early diagnosis and treatment of the most common liver affection diseases as HCV.