Comparison Of Commercial ELISA Tests For Johne's Disease In Beef Cattle Herds

Abstract

The prevalence of Johne's disease throughout the United States has prompted the development of several USDA approved ELISA kits. These test kits are widely used in diagnostic labs throughout the country. As numbers of beef producers utilizing these ELISA tests to detect Johne's disease increase, it becomes important to critically evaluate the performance of these diagnostic tests specifically in beef cattle.

The aim of this study was to evaluate the specificity and agreement between the three commercially manufactured ELISA tests for Johne's in beef cattle herds. Two-thousand fifty-four sera samples were collected from six beef herds in Iowa, South Dakota and Georgia. The samples were ran according to manufacturer's recommendations. The results were evaluated based upon specificity in negative herds, and kappa statistics were calculated for both positive and negative herds. The specificities ranged between 90.48 and 9.41 %. Agreement between tests ranged from k-0.394-0.061 in negative herds and k-0.503-0.310 in positive herds. These data indicate a significant difference between commercial ELISA tests.