Mycobacterium bovis: Characteristics of wildlife reservoir hosts

Authors: Palmer, Mitchell

Submitted to: Transboundary and Emerging Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/4/2013
Publication Date: 11/1/2013
Publication URL: http://handle.nal.usda.gov/10113/58893
Citation: Palmer, M.V. 2013. Mycobacterium bovis: Characteristics of wildlife reservoir hosts. Transboundary and Emerging Diseases. 60(1):1-13.

Interpretive Summary: Tuberculosis in animal, and sometimes humans, is caused by the bacteria known as Mycobacterium bovis (M. bovis). Since 1917 the US, like many countries, has been working to eliminate tuberculosis from cattle. These efforts have been made more difficult by the presence of tuberculosis in wildlife, specifically white-tailed deer in Michigan, USA. Tuberculosis in wildlife acts as a continuous source (reservoir) of disease for cattle herds located in areas where tuberculous wildlife exist. Persistent deer to cattle transmission of disease make elimination from cattle impossible. World-wide, other recognized wildlife reservoirs of M. bovis include the brushtail possum in New Zealand, European badger in Great Britain and Ireland, African buffalo in South Africa, and wild boar in the Iberian Peninsula. There may be one or many wildlife reservoirs in any given situation. Circumstances with multiple wildlife reservoirs create complex systems with transmission among and between multiple potential reservoir hosts. Identifying wildlife reservoir hosts is critical as disease control efforts are most effectively aimed at reservoir hosts and should not be limited to cattle.

Technical Abstract: Mycobacterium bovis is the cause of tuberculosis in animals and sometimes humans. Many countries have long-standing programs to eradicate tuberculosis in livestock, principally cattle. As disease prevalence in cattle decreases, eradication efforts are impeded by passage of M. bovis from wildlife to cattle. Disease can persist in wildlife maintenance (reservoir) hosts through intraspecies disease transmission, without contributions from a different infected animal host species. Recognized wildlife reservoir hosts of M. bovis include the brushtail possum in New Zealand, European badger in Great Britain and Ireland, African buffalo in South Africa, wild boar in the Iberian Peninsula, and white-tailed deer in Michigan, USA. In some cases there is a single wildlife reservoir host involved in transmission of M. bovis to cattle; however, in some countries there are complex multi-host situations with transmission among and between multiple potential reservoir host species. In both single- and multi-host epidemiological systems there are often spillover host species that become infected, but do not contribute to the overall epidemiology of disease. Identifying reservoir host species is critical as disease eradication or control efforts are most effectively aimed at reservoir hosts.