A new USDA approved ELISA is available for detection of antibody against Mycobacterium avium subspecies paratuberculosis (Johne’s disease) in serum from cattle or goats or milk from cattle. The new ELISA was tested and verified at the Michigan State University Veterinary Diagnostic Laboratory (MSU VDL) as equivalent with the previous in-use ELISA for detection of antibody in serum or milk from cattle. The MSU VDL has taken and passed USDA administered proficiency tests using the new ELISA.
Effective June 17, 2020 the MSU VDL will switch to the new ELISA, which will allow goat owners to request either the ELISA or the agarose immunodiffusion (AGID) assay to test for Johne’s disease. The new ELISA will provide beef and dairy producers an S/P ratio as was reported with the previous ELISA for Johne’s disease.