Abstract
Oesophagostomosis is one of the most prevalent nematodosis with considerable economic losses in small ruminant livestock. Prepatent stage of Oesophagostomum columbianum is primarily involved in the major pathogenic effect of the infection and conventional methods are unable to detect this stage. An indirect enzyme linked immunosorbent assay (ELISA) was therefore standardized and evaluated for the purpose to improve diagnosis and thereafter minimize the economic losses due to this infection in goat. The eggs obtained from O. columbianum adult female worms, collected from caecum and colon of slaughtered goats, were cultured to obtain the third stage larvae (L3). Crude somatic antigen (CSAg) was prepared from triturated worms. Experimental goats (n = 12) were orally infected each with 600 L3 /kg body weight. Serum samples of the infected goats were collected at 2-day-interval from day-3 till day-33 post infection. The indirect ELISA was standardized using the CSAg for coating the wells, infected goat sera as binding antibody, anti-goat IgG-HRP conjugate and ortho-phenylenediamine (OPD) with peroxide as substrate. The sensitivity, specificity and accuracy of ELISA were determined by testing 96 serum samples of goats whose parasitological status after slaughter was determined by examination of the abomasums and the intestines. O. columbianum antibodies were detected in sera of infected goats on day 18 – 27 post-infection with 96.00, 73.91 and 85.42 per cent sensitivity, specificity and accuracy, respectively.