Evaluation of competitive ELISA for detection of antibodies to Brucella infection in domestic animals.

AIM To evaluate competitive enzyme-linked immunosorbent assay (cELISA) for its suitability as an additional serological test for the diagnosis of animal brucellosis. METHODS cELISA, which was developed at the Veterinary Laboratories Agency, has been evaluated for its accuracy and suitability as an additional serological test for the diagnosis of animal brucellosis. Samples from naturally and experimentally infected animals and those from Brucella-free flocks and herds were tested. RESULTS Data obtained since 1991 were analyzed from routine surveillance, animals experimentally infected with Brucella, and stored sera to validate cELISA for the detection of antibodies to Brucella in cows, small ruminants, and pigs. The sensitivity of the test ranged from 92.31% to 100%, in comparison with 77.14% to 100% for the complement fixation test (CFT). Specificities for cELISA, indirect enzyme-linked immunosorbent assay, and CFT were greater than 90%. CONCLUSION cELISA can be used on a variety of animal species, and an added advantage is its suitability for use on poor-quality samples such as those affected by hemolysis.