An evaluation of seroreactivity of antigenic preparations of Fasciola gigantica in goats

Abstract

Seroreactivity of Fasciola gigantica, somatic (SAg), excretory-secretory (ESAg) and egg (EAg) antigens, was evaluated using immunodiffusion tests (DID and CIEP) and enzyme-linked immunosorbent assay (ELISA). The referral antigens were evaluated against 50 Fasciola-free vis-a-vis 50 Fasciola-positive serum samples collected from goats slaughtered at local abattoir. The goats positive far infection, had low fluke recovery of 27±12. The immunodiffusion tests (DID and CIEP) had higher specificity (98 and 96%) than ELISA (92%), in detecting the fasciolosis-positive goats. Amongst the 3 tests used, ELISA with SAg had the highest sensitivity (96%), whereas with EAg, the lowest (82%) and ESAg occupied position closer to SAg. In CIEP, the egg antigen performed better in detecting low grade infection of caprine fasciolosis than SAg or ESAg. The formation of perception lines in proximity of EAg containing wells (cathodic end) in CIEP, was suggestive of high molecular weight of Fasciola gigantica specific moieties in egg antigen. Purification, isolation and characterization of such protein molecules from the referral antigens has been suggested for further qualitative improvement.