Tuberculosis is an infectious disease that is mutually transmissible between humans and animals and therefore belongs to the zoonoses.Tuberculosis pathogens are grouped together as the "Mycobacterium tuberculosis complex" because of their close relationship. They do not differ in their 16S rRNA gene, so taxonomically they all belong to one species, Mycobacterium (M.) tuberculosis. However, members of the M. tuberculosis complex differ in other areas of their chromosome, their adaptation to different hosts, and their pathogenicity to individual mammalian species or humans. Therefore, they are classified into different species, named respectively after their primary hosts or first descriptions:
M. tuberculosis (human), M. africanum (human; Africa), M. bovis (bovine), M. caprae (bovine, caprine), M. orygis (antelope), M. microti (mouse), M. pinnipedii (seal), Dassie bacillus (cliff slate), Chimpanzee bacillus (chimpanzee), M. mungi (mongoose), and M. suricattae (meerkat). Also included in the complex is the vaccine strain M. bovis BCG, which is greatly attenuated in virulence.
The World Organization for Animal Health (WOAH, founded as OIE) lists bovine tuberculosis as a listed disease. These are "communicable diseases of socio-economic importance and/or of public health importance and of international trade in animals and animal products". Under the EU's new animal health legislation, since April 21, 2021, infections with M. tuberculosis, M. bovis or M. caprae (MTBC) in cattle of the genera Bison ssp., Bos ssp. and Bubalus ssp. are among the "listed diseases" of category B, D and E, with the aim of eradicating them throughout the Union.
In Germany, bovine tuberculosis is a notifiable animal disease. It has been considered eradicated in western Germany since the early 1960s and in eastern Germany since the late 1970s due to intensive government control procedures. Since 1997, Germany has been officially recognized by the EU as free of bovine tuberculosis. For this recognition, at least 99.9% of the cattle herds had to be officially free of tuberculosis in each year and in each of the previous ten years. Since then, control and surveillance have been based mainly on the diagnosis of clinical changes, official slaughter meat inspection, necropsies of dead animals at veterinary inspection offices, and tuberculinization (skin testing) in certain cases. In case of clinical suspicion or pathological changes in the tissue, diagnostic investigations (bacteriology, molecular biology, epidemiology, tuberculinization of contact animals, gamma interferon test) are initiated to clarify the suspicion. To prevent transmission of tuberculosis through milk, pasteurization is still the best protective measure. Even under the new EU legislation and the implementing regulation (EU) 2021/620, the entire territory of Germany continues to have "disease-free" status with regard to infections with MTBC.