Johne's disease is an enteric infection of grazing ruminants and llamoids caused by Mycobacterium paratuberculosis. The ELISA has a reported specificity of >99% indicating that an animal with a positive result almost certainly has Johne's infection. The sensitivity of the ELISA depends on the stage of the disease. In preclinical cases that are faecal culture positive, the sensitivity is approximately 60%. However, with clinically affected animals, the sensitivity improves to approximately 87%.
This test is indicated when ill thrift is present in animal at risk of Johne's disease.
CFT and AGID are other serological tests and faecaZeihl Nielsen stains are also possible to check for acid fast organisms.
Ovine, cervine, bovine, llamoid, caprine
Plain or gel tube