Location: Infectious Bacterial Diseases ResearchTitle: Evaluation of antibody and cell-mediated based tests for detection of bovine tuberculosis in United States' cattle Author
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/20/2014
Publication Date: 6/16/2014
Citation: Antognoli, M.C., Orloski, K.A., Waters, W.R., Francisco, T.I., Nelson, J., Robbe-Austerman, S., Hall, M., Thomsen, B.V., Meyer, R. 2014. Evaluation of antibody and cell-mediated based tests for detection of bovine tuberculosis in United States' cattle [abstract]. Abstract No. 48. Interpretive Summary:
Technical Abstract: Bovine tuberculosis (BTB) was detected in a United States (US) dairy in 2010 through slaughter surveillance. The high apparent bTB prevalence (29% caudal fold tuberculin test (CFT) suspects) revealed after whole herd testing, offered an opportunity to revisit the performance of US official antemortem BTB tests and to evaluate developmental tests in a natural infection setting. The evaluation addressed the sensitivity (Se) of the interferon gamma release assay (IGRA) as a supplemental test, the CFT, and the comparative cervical tuberculin (CCT) test; the Se and specificity (Sp) of the IGRA as a primary test (i.e., without a prior intradermal injection of bovine tuberculin); and the sensitivity and specificity of three serological tests. Test Se was evaluated in a herd (n=908) with a true bovine tuberculosis (TB) prevalence of 11.1%. Convenient samples were collected in the context of the official bovine TB program activities. Samples collected from cattle in non-infected trace out herds were used to calculate test specificity. The sensitivity of the IGRA as a supplemental test was 81.9% (71.1, 90.0) and the sensitivity of the CCT was 88.9% (79.3, 95.1). The sensitivity of the CFT was 75.3% (65.5, 83.5) and the sensitivity of the IGRA as a primary test applied to a subset of CFT-positive cattle was 61.6% (49.5, 72.8). The serology tests achieved sensitivity estimates ranging from 24.4% to 58.5% with specificities ranging between 87.6% and 100%. All serology tests evaluated in this study had comparably low sensitivity but high specificity and most showed some value in identifying lesioned animals that were not detected by the CFT and IGRA. When used in parallel with the CFT, these serology tests could be valuable in detecting animals that failed to respond to cell-mediated based tests.