Bovine tuberculosis g-interferon and interleukin-2 receptor tests in cattle.

摘要

Inconclusive g-interferon receptor tuberculosis tests can be resolved by inducing expression of interleukin-2 receptor as immune marker for M. bovis on same blood sample. Seventy-five of 765 samples were g-interferon positive (9.8%), 9 dubious (1.18%)and 14 negative. Sixty four cattle had same result by both tests (67.4%). Of 95 cattle slaughtered, 38 were TB lesion-positive with 36 g-interferon positive and 2 dubious. By IL-2 R assay, 33 scored positive, 1 negative and 4 dubious. No g-interferon negatives scored positive by IL-2R assay but 10 g-interferon positive and dubious samples scored negative. Forty-two g-interferon positive and 34 dubious M. bovis-positive or suspect farms tested by IL-2R assay yielded 16 SICT-positive. Thirty-five of 42 g-interferon positive were positive by IL-2R assay, 5 negative and 2 dubious. Twenty g-interferon dubious animals were scored positive but 10 negative by IL-2R assay and 4 dubious. By SICT 13 of 16 were positive in IL-2R assay (81%). We found no discrepancy with IL-2R assay for g-interferon negative cattle. Blood from M. bovis-positives appeared negative by g-interferon or IL-2R assays. We find both tests to have low specificity but high agreement.