Background: Fasciolosis is a worldwide disease with major economic and public health consequences. Early detection of the infection is important for the prevention and control of the disease. ELISA allows for early detection of fasciolosis in man and animals. Fasciolosis is caused by Fasciola hepatica and F. gigantica in man and domestic animals respectively. These two species have many similar morphological characteristics. In this study, the crude antigens of these two species are investigated by ELISA test.
Methods: The excretory-secretory and somatic antigens of two species were prepared from adult flukes collected from the bile ducts of sheep and stored at -20oC. For the preparation of the antisera, the antigens were injected to laboratory-bred rabbits. Each rabbit received five injections at intervals of seven days, starting with 0.5 ml and ending with 2.5 ml. Ten days after the last injection, the rabbits were bled, and serum samples separated and stored at -20oC. The reaction between homologous and heterologous antigens and antisera was tested by ELISA and optical densities were recorded.
Results: Excretory- secretory and somatic antigens of each species showed a strong positive reaction with the antisera of the other species. In a homologous combination of antigens and antisera, a stronger reaction was observed compared to the heterologous combination, therefore many antigenic materials of both species are the same.
Conclusion: The differences of these crude antigenic materials of F. hepatica and F. gigantica are insufficient to prevent cross reaction of two species by ELISA. Further investigations are recommended for the identification, detection and purification of antigenic material of each species to improve the specificity of this assay.
