Johne's disease is an enteric infection of grazing ruminants and llamoids caused by Mycobacterium paratuberculosis. This test has a reported specificity of >99% indicating that an animal with a positive result almost certainly has Johne's infection. The sensitivity of the test 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%.
Serum ELISA is the first test of choice. Serum CFT is used for specific requirements of some countries and for ancillary testing. ELISA and AGID are other serological tests and faecal Zeihl Nielsen stains are also possible to check for acid fast organisms
Species:
Ovine, cervine, bovine, llamoid, caprine
Specimen:
Serum
Container:
Plain or gel tube
Collection protocol:
Venepuncture