Location: Infectious Bacterial Diseases ResearchTitle: Tuberculosis in wild and captive deer Author
|De Lisle, Geoffrey|
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 5/19/2014
Publication Date: 9/28/2015
Citation: Palmer, M.V., O'Brien, D.J., Griffin, J.F., Nugent, G., De Lisle, G.W., Delahay, R.J. 2015. Tuberculosis in wild and captive deer. In: Mukundan, M., Chambers, M. Waters, R., Larsen, M., editors. Tuberculosis, Leprosy, and Mycobacterial Diseases of Man and Animals: The Many Hosts of Mycobacteria. Boston, MA: Centre for Agriculture and Biosciences International. p. 334-364. Interpretive Summary:
Technical Abstract: Deer are found on every continent, save for Antarctica and Australia. Of the over 50 species of deer worldwide, tuberculosis due to Mycobacterium bovis has been documented in at least 14. The broad host range of M. bovis includes most mammals, including humans and livestock. Eradication programs have decreased the prevalence of disease in livestock; however, tuberculosis in wild and captive deer represents an obstacle to eradication. In a wild setting, deer can be spillover hosts, maintenance hosts or components of a multi-host system. In the US, New Zealand and Spain, infected wild deer act as a reservoir of disease, transmitting tuberculosis to livestock, other wildlife and sometimes humans. Complete elimination of a wildlife reservoir through lethal methods is both impractical and irresponsible. Vaccination of wild deer represents a potential management tool to decrease infection, disease and transmission. The human vaccine, M. bovis BCG has demonstrated efficacy in red deer and white-tailed deer, showing decreased disease severity, but not protection from infection. It is hypothesized that deer with mild disease are less likely to transmit M. bovis than those with severe disease. Trials examining oral vaccination of deer, and other wildlife, are in progress. In contrast, captive deer are farmed and managed much like livestock, are housed at stocking rates much higher than wild deer and are sold or traded domestically and internationally, creating enhanced potential for disease spread. Standard tuberculin skin tests do not have sufficient sensitivity to eradicate disease from captive deer through test and removal. The alternative (and current practice) is whole herd depopulation, which is extreme, costly and unpopular. Lack of test specificity is complicated by the many non-tuberculous mycobacteria that can innocuously infect deer. Improved diagnostic tests are a topic of active research. Elimination of tuberculosis from livestock will require concurrent elimination of disease in wild and captive deer, which will require efficacious vaccines and reliable, accurate diagnostic tests.