Tuberculosis in domestic ruminants: towards eradication of zoonotic tuberculosis

Abstract

Tuberculosis (TB) is a zoonosis with a significant impact on human and animal health and it remains endemic in many countries around the world. Most cases of human TB are caused by Mycobacterium tuberculosis, whilst TB in wildlife and domestic ruminants is mainly caused by animal adapted mycobacterial species such as M. bovis and M. caprae. However, the impact of zoonotic TB (zTB) has been known for a long time and resulted in the implementation of milk pasteurization as a preventive public health measure in many countries. According to data published by the WHO, more than 140,000 people are infected and more than 12,000 die every year due to zTB, particularly in the African and Southeast Asian regions. Zoonotic M. bovis transmission represents 0.4% of all cases in the EU, although this may be underestimated, as it is not always possible to confirm the TB species involved, or conduct appropriate epidemiological investigations. Livestock TB control programs were originally implemented to reduce zTB. Successes in controlling infections in livestock, together with measures to control animal products with suspected infection have contributed to lowering the annual incidence of cases of zTB in high-income countries. The incidence tends to be higher in countries where animal and public health resources are inadequate to manage costly bovine TB control programs. TB eradication is difficult to achieve mainly due to: (I) limited knowledge of the complex immunological response against the infection, (II) complex epidemiology, including several domestic and wildlife reservoirs, (III) the absence of an effective vaccine, (IV) a limited performance of the current diagnostic tests, and (V) societal aspects. Therefore, there is a need to continue working on these fields of TB research. In this Research Topic, different aspects of the epidemiology, diagnosis and control of TB in wildlife and domestic ruminants have been addressed to increase the knowledge about this important zoonotic disease. This will contribute to TB eradication in domestic ruminants, which also represents an important step to reduce the zTB.