Comparative analysis of serological tests and fecal detection in the diagnosis of Mycobacterium avium subspecies paratuberculosis infection

Abstract

© 2020 Korean Society of Veterinary Science. All rights reserved.Johne's disease (JD) caused by Mycobacterium avium subspecies paratuberculosis (MAP) is a chronic, wasting infectious disease in ruminants that causes enormous economic losses to the dairy and beef cattle industries. The most effective way to eradicate JD is to detect infected individuals as early as possible and remove them from the herd. However, it is difficult to detect infected individuals early with the currently using diagnostic methods. Two serological diagnostic kits commercially used worldwide and a fecal detection test were compared using 298 serum samples and feces of cattle in this study to present an efficient diagnostic method. Although there was a high correlation between the 2 serological diagnostic kits (R2 = 0.7473), kit A showed a higher serological positive rate. However, the correlation between fecal tests and serological diagnosis was very low. MAP was also detected in fecal tests in many serologically negative individuals. In the periodical diagnosis of JD, MAP was detected in the feces of only cows with the higher antibody titer to MAP. These results suggest that for effective eradication of JD, early detection of infected individuals by fecal tests together with the serological tests currently in use and by removal of infected individuals are needed.