ASSESSMENT OF AN INDIRECT ELISA IN MILK FOR THE DIAGNOSIS OF OVINE BRUCELLOSIS

The possibility of using an ELISA for the diagnosis of ovine brucellos is in milk (M-ELISA) was investigated. The aim of the study was to est ablish whether the specificity and sensitivity of the M-ELISA would be high enough to detect low levels of Brucella antibodies in ewe milk. The diagnostic performances of the test under study were established b y means of reference standards and compared with conventional screenin g and confirmatory tests under field conditions. The diagnostic specif icity of the M-ELISA established on a number of samples from Brucella- free flocks was 100% while relative to RBT and CFT positive reactors t he M-ELISA demonstrated sensitivity of 65 and 83% respectively. Its se nsitivity relative to culture positive animals was of 92%. The course of Brucella antibodies in milk of positive sheep was evaluated in colo strum and in mature milk for a period of 30 days after delivery and it appeared that concentrations of immunoglobulins in milk tend to sharp ly decrease soon after parturition while in blood serum these remained constantly high. It was concluded that the M-ELISA for Brucella antib odies in ewe milk can be regarded as a complementary diagnostic tool f or individual testing but it would be poorly viable if used as a scree ning test applied to pooled flock milks.