A review of bovine tuberculosis at the wildlife–livestock–human interface in sub-Saharan Africa

Abstract

SUMMARYInfection of wild animals by bovine tuberculosis (bTB) is raising concern worldwide. This article reviews the current epidemiological situation, risk of emergence and control options at the wildlife-livestock-human interface in sub-Saharan Africa. In livestock, bTB has been confirmed in the majority of countries from all parts of the continent. Wildlife infection is confirmed in seven countries from southern and eastern Africa, apparently spreading in the southern Africa region. Mycobacterium bovis has been isolated from 17 wild mammal species, although only four are suspected to play a role as maintenance host. Zoonotic risks are a concern, but no direct spillover from wildlife to humans has been documented, and no case of bTB spillback from wildlife to livestock has been confirmed. In this paper we assess the main risk factors of bTB spillover at the wildlife-livestock-human interface and suggest several research themes which could improve the control of the disease in the African context.

Updated Reference Genome Sequence and Annotation of Mycobacterium bovis AF2122/97

“…bTB exacts a tremendous global economic toll through productivity losses and disease control costs, while zoonotic transmission of M. bovis infection is a threat to human health (1–6). …”

Spillover ofMycobacterium bovisfrom Wildlife to Livestock, South Africa

“…However, in developing countries in southern Africa and elsewhere, bovine tuberculosis remains a challenge to animal health because of a total or partial lack of bovine tuberculosis control, limited by a lack of funds ( 1 , 2 ). The control and/or elimination of bovine tuberculosis in both developing and industrialized countries can be complicated by wildlife reservoirs of the disease, which pose a threat of re-infection in livestock ( 3 ). In sub-Saharan Africa, particularly South Africa and Uganda, African buffalos ( Syncerus caffer ) serve as wildlife reservoirs of bovine tuberculosis; in Zambia, lechwe antelopes ( Kobus leche Kafuensis ) have been identified as wildlife reservoirs ( 4 , 5 ).…”

“…Except for data from sporadic regulatory bovine tuberculosis surveillance activities in cattle adjacent to the GKNPC, no data exist on the transmission of bovine tuberculosis from the GKNPC, where it is endemic, into livestock in neighboring communities ( 3 ). Because of the potentially negative implications of livestock–wildlife interactions on livestock and human health, the presence and role of zoonotic diseases in these communities needs to be investigated ( 5 ).…”

Enemies and turncoats: bovine tuberculosis exposes pathogenic potential of Rift Valley fever virus in a common host, African buffalo ( Syncerus caffer )

“…Within KNP, BTB prevalence ranges from 0 to 1% in the northern section of the park to 50% in the southern section of the park, where BTB first was found [55]. As BTB continues to move north within KNP, crossing into Zimbabwe [56], RVF epidemics in African buffalo may increase in size. Whether this potential increase in RVF-infected buffalo will increase the risk of outbreaks extending into humans, domestic livestock or free-ranging ruminants needs to be investigated.…”