Comparison of DNA probe test and cultivation methods for detection of Mycobacterium avium subsp paratuberculosis in caprine and ovine faeces

Objective To compare a DNA probe test with two cultivation methods for the detection of Mycobacterium avium subsp paratuberculosis in goat and sheep f aeces. Design Comparison of the results of the three methods with histological exa mination as the reference standard. Procedure Faecal specimens were obtained from goats and sheep originating f rom flocks known to be affected with paratuberculosis and tested for Mycoba cterium avium subsp paratuberculosis with a DNA probe test and two cultivat ion methods told conventional culture and new double incubation method in H errold's and Lowenstein-Jensen medium). Results In goats, the sensitivity of the various tests were for the DNA pro be test 17.2%, for the double incubation culture method 25.4% and for the o ld conventional culture method 22.8% using the histopathological results as reference. In sheep the sensitivity of the various tests were for the DNA probe test 13.2%, for the double incubation culture method 8.8% and for the old conventional culture method 5.9% using the histopathological results a s reference. The specificity of the above tests was 100% in goats and sheep and the specificity of the double incubation culture method in goats was 9 1%. Conclusions The DNA probe test is a rapid and specific test that could be u sed in a control program if the sensitivity of the test were improved and p ossibly in combination with another test.