Submitted to: Journal of Wildlife Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/29/2008
Publication Date: 1/20/2009
Citation: O'Brien, D.J., Schmitt, S.M., Lyashchenko, K.P., Waters, W.R., Berry, D.E., Palmer, M.V., Mcnair, J., Greenwald, R., Esfandiari, J., Cosgrove, M.K. 2009. Evaluation of Blood Assays for Detection of Mycobacterium Bovis in White-tailed Deer (Odocoileus Virginianus) in Michigan. Journal of Wildlife Diseases. 45(1):153-164. Interpretive Summary: White-tailed deer are wildlife reservoirs of bovine tuberculosis within the United States. The presence of this reservoir host seriously threatens ongoing efforts to eradicate this disease from cattle. New strategies have been developed to capture and test free-ranging deer for tuberculosis infection. A reliable and easy blood tuberculosis test would enable this strategy to be effective. In the present study, it was determined that deer naturally infected with tuberculosis produce antibodies to the bacterium and that these antibodies are detectable by simple laboratory methods. These findings will be useful for the control of bovine tuberculosis in deer, thus, benefiting the cattle industry and potentially decreasing the spread of tuberculosis from deer to cattle.
Technical Abstract: Surveillance and control activities for bovine tuberculosis (TB) in free-ranging Michigan white-tailed deer (Odocoileus virginianus) have been underway for over a decade, with significant progress. However, foci of higher TB prevalence on private land, and limited agency ability to eliminate them using broad control strategies, has led to development and trial of new control strategies, such as live trapping, testing and culling or release. Such strategies require a prompt, accurate live animal test, which has thus far been lacking. We report here the ability of seven candidate blood tests to determine the TB infection status of Michigan deer. Our aims were twofold: to characterize the accuracy of the tests using field-collected samples, and to evaluate their feasibility for use as part of a test and cull strategy. Samples were collected from 760 deer obtained via five different surveys conducted between 2004 and 2007. Blood samples were subjected to one or more of the candidate blood tests and evaluated against the results of mycobacterial culture of the cranial lymph nodes. Sensitivities of the tests ranged from 46 to 68%, while specificities and negative predictive values were all >92%. Positive predictive values were highly variable. A exploratory analysis of associations between several host and sampling-related factors and the agreement between blood test and culture results suggested these blood tests were minimally affected. This study demonstrated that several available blood tests for M. bovis can yield reasonably accurate results on specimens obtained through a variety of field surveillance methods. Such tests may prove increasingly useful as wildlife disease managers develop innovative methods of detecting infected animals where mass culling is publicly unacceptable as a control strategy.