Mervat Zakaria El Azzouni, Rasha Fadly Mady, Maha RedaGaafar, FadwaArafa andAbeerElhadidi
Departments of MedicalParasitology, Faculty of Medicine Alexandria University, Egypt
Schistosomiasis is a truly neglected tropical disease and the second major parasitic disease in the world after malaria. It affects 201.5 million cases in Africa alone. The goal of this research is the development of an appropriate vaccine against experimental schistosomiasismansoni, we assessed the effect of cercarial transformation fluid (CTF) singly and in combination with crude cercarial antigen (CCA) using alum as an adjuvant in experimentally infected mice. The combined antigen gave the best results as evidenced by significant reduction in the worm load (62.07%), tissue egg count, (78.16%, 86.46%) in liver and intestine respectively and hepatic granuloma size (31.76%). Scanning electron microscopic study revealed changes in the tegument in the form of roughness and appearance of vesicles and furrows between the tegumental tubercles. Also, resorption and mutilation of the ventral sucker and dimples replacing its spines. The female tegument was irregular and its posterior end showed loss of spines and sensory bulbs. Moreover there was a significant decrease in liver enzymes (ALT and AST) compared to infected control mice. A significant elevation in CD4+ T-lymphocytes denoting amelioration of the immune status in animals received combined vaccine.
It can be concluded that this combined antigen give us a hope to the development of a feasible simple vaccine against Schistosomiasismansoni.
Keywords:Schistosomiasismansoni, tropical disease and cercarial transformation fluid.