Historical Perspective of BTB in Nigeria
Manley (1929) first reported the presence of BTB in Nigeria in 1929, when it was first diagnosed in purebred and half-bred cattle imported from Germany based on a tuberculin test, post-mortem examination, and laboratory confirmation.
The Nigerian cattle herds were assumed to also have been infected by being in contact with Cameroonian herds, where BTB in West Africa was first reported in 1913, due to their historical cultural links, and the extensive transhumant movement of pastoralists from Nigeria and other West African countries, including Cameroon (Alhaji 1976). That cattle from these countries were the source of the infection was further strengthened by the presence of the Af1 clonal complex, a major strain of M. bovis in Cameroon, Chad, Mali, and Nigeria. Further epidemiological evidence showed that most TB-infected cattle slaughtered in Southern Nigeria originate from Northern Nigeria and the neighboring Francophone countries, Cameroon, Chad, and Niger (Muller et al. 2009). Strains of M. bovis prevalent in Northern Nigeria and neighboring countries (Cadmus et al. 2011) were also isolated from cattle in Southwestern Nigeria (Cadmus et al. 2006).Due to the limited availability of pasture and water in Northern Nigeria, particularly during the dry season, some of the Fulani pastoralists from the north settled in South-western Nigeria about five decades ago. The Nigerian government, in an attempt to sustain their livelihood, established grazing reserves in Oyo State, Southwestern Nigeria, which subsequently became the convergent hub for animals from Northern Nigeria, the neighboring West African countries, and resident herders, creating a melting pot of diverse livestock diseases, including BTB.
The absence of an active BTB surveillance program in Nigeria further compounds the problem. Disease reporting is not mandatory, and consequently there is a gap in the information needed for its control (Cadmus and Ayanwale 2014). Additionally, because of the very few adequately trained human resources involved in BTB research, and inadequate diagnostic facilities to monitor the disease status, BTB remains highly under-diagnosed and poorly investigated in Nigeria. The actual economic loss associated with BTB and its impact on livestock production in the country cannot be calculated accurately, while its public health implications also remain in the realm of conjecture.
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