Public Heath Implication of M. bovis
Mycobacterium bovis is a potential health hazard, both for animals and humans, and the risk of becoming infected depends on the route of transmission. In Burkina Faso, aerosol transmission is strongly facilitated by the close and prolonged contact between diseased animals and pastoralists (Gidel et al.
1969b), such as the Fulani, who have an increased risk of contracting BTB due to their livestock-associated lifestyle. The Fulani ethnic group has a higher rate of the pulmonary form of TB compared to populations that are not as exposed to M. bovis-infected cattle (Vekemans et al. 1999).The oral route of transmission following consumption of infected milk and meat products also presents a considerable risk of M. bovis transmission from animals to humans and vice versa (Vekemans et al. 1999; Tarnagda et al. 2014). In Burkina Faso, the zoonotic risk associated with the consumption of meat and dairy products from diseased animals appears to be important. Mycobacterium bovis was isolated from nearly 22% of dairy products collected from small markets and industrial dairy farms in Bobo-Dioulasso (Vekemans et al. 1999). The risk of contracting BTB appears to be particularly high in the Sahelian regions where milk is usually consumed raw and where the BTB infection rates in cattle are typically high, especially in older cows. The risk of contracting TB by humans is three times higher in villages with high BTB infection rates than in BTB-free villages (Rey et al. 1986). It seems therefore that the high TB prevalence in young children may be related to the prevailing high prevalence of BTB in the local cattle population, suggesting that M. bovis infections may be more prevalent in these populations than anticipated.
Determining the actual zoonotic role of M. bovis in Burkina Faso is difficult particularly because of the lack of adequate diagnostic facilities and techniques, and the true prevalence of M. bovis infection in the human population remains unknown. The risk of contracting zoonotic BTB in Burkina Faso will remain until such time that adequate surveillance, good hygienic practices (including pasteurization of milk and cooking of meat), and other good public health practices are instituted.
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