Immunodiagnosis of bovine gastrothylacosis using coproantigens

Abstract

A study was conducted on the prevalence of paramphistomatidosis in Thrissur from June 1999 to May 2000, feasibility of coproantigen detection by ELlSA and comparison of sensitivity of ELlSA using coproantigens and ELlSA using serum antibodies in diagnosis of gastrothylacosis, caused by Gastrothy/ax crumenifer, in cattle. It was noted from the registers maintained at the University Veterinary Hospitals at Kokkalai and Mannuthy and that at the Department of Veterinary Parasitology, College of Veterinary and Animal Sciences, Mannuthy, that out of a total number of 1534 faecal samples from bovines examined, 253 (16.5 per cent) animals were found to be positive for amphistome eggs with the maximum prevalence (23 per cent) in June and July. Generally the infection was prevalent throughout the year. An indirect ELlSA using rabbit hyperimmune serum against somatic antigens of G. crumenifer was performed to detect coproantigens in faecal samples collected from 100 known G. crumenifer infected cattle. Seventy four samples were found to contain detectable levels of coproantigen indicating a sensitivity of 74 per cent. Serum samples collected from the same infected cattle were tested for antibodies to G. crumenifer by an indirect ELlSA using somatic antigens. Fifty one samples were found positive for antibodies indicating a sensitivity of 51 per cent.

It was seen that when 43 cattle were positive for both coproantigens and serum antibodies, 18 cattle were negative for both of them. Although 31 cattle which were negative for serum antibodies were found positive for coproantigens, eight cattle negative for coproantigens were found positive for serum antibodies. The results showed that coproantigen detection, which revealed a higher sensitivity than the detection of serum antibodies by ELlSA, is feasible for the diagnosis of gastrothylacosis in bovines.