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.
- Contact for federal and state authorities for questions related to bovine tuberculosis diagnostics and control
- Support of the investigation offices in the clarification of suspected cases
- Supply of reference material for the investigation offices of the federal states in Germany
- Updating of methodological recommendations for laboratory diagnosis (detection, isolation and differentiation) of the tuberculosis pathogens
- Characterization of isolates
- Identification of sources of infection, as well as elucidation of chains of infection
- Performance of national interlaboratory proficiency test
- Participation in EU ring tests
- Training of laboratory personnel in mycobacterial diagnostics
- Differentiation of submitted isolates
- Cultivation of mycobacteria from test material
- Species identification by polymerase chain reaction (PCR)
- Detection of pathogen-specific DNA directly from infected tissue (real-time PCR)
- Genotyping by molecular methods:
- Spoligotyping (differentiation of members of the Mycobacterium tuberculosis complex).
- MIRU-VNTR typing (analysis of repetitive DNA sequences)
- DNA sequence analysis (PCR amplification, WGS)
- Identification of sources of infection and investigations of infection chains
- According to Regulation (EU) 2016/429 ("Animal Health Law") and Implementing Regulation (EU) 2018/1882, the detectionof MTBC in Artiodactyla (except Bison ssp., Bos ssp., Bubalus ssp.) is one of the listed diseases of category D and E, i.e. diseases whose spread is to be prevented by entry into or movement within the Union.
This categorization and the Delegated Regulation (EU) 2020/688 result in requirements for certain animal species for which on-farm monitoring programs are necessary if animals from these herds are to be moved within the EU. These include goats, camelids and cervids. Among other requirements, all animals kept for breeding purposes must be subjected to annual testing with negative results.
While for goats the skin test prescribed by the European Reference Laboratory (EU-RL) is available for monitoring, for the other two animal groups corresponding diagnostics are not available in Germany. The NRL performs evaluation studies on the use of the ELISA prescribed by the EU-RL in camelids. For cervids, the EU-RL does not yet specify any requirements for testing.
- According to Regulation (EU) 2016/429 ("Animal Health Law") and Implementing Regulation (EU) 2018/1882, the detection of MTBC in terrestrial mammals belongs to category E. Here, the NRL assists in the clarification of suspected cases, especially in the diagnosis of possible MTBC infections, by means of genome detection and/or cultural cultivation.
- The NRL is interested in receiving all German M. tuberculosis complex isolates originating from animals for genotyping. The aim is to build up a database that can be used to quickly and efficiently identify chains of infection and/or new entries from abroad.
- Regulation on notifiable animal diseases
- Regulation for protection against bovine tuberculosis
- VO (EU) 2016/429 Animal Health Law, Annex II „List of Diseases“ (changed by Delegated Regulation VO (EU) 2018/1629): Infection with Mycobacterium tuberculosis complex (M. bovis, M. caprae and M. tuberculosis)
- Implementing Regulation (EU) 2018/1882 „Application of certain disease prevention and control rules to categories of listed diseases and establishing a list of species and groups of species posing a considerable risk for the spread of those listed diseases“
- Implementing Regulation (EU) 2021/620 “Application of Regulation (EU) 2016/429 of the European Parliament and of the Council as regards the approval of the disease-free and non-vaccination status of certain Member States or zones or compartments thereof as regards certain listed diseases and the approval of eradication programmes for those listed diseases”
- Implementing Regulation (EU) 2022/214 amending certain annexes to Implementing Regulation (EU) 2021/620
- Delegated Regulation (EU) 2020/688 „Animal health requirements for movements within the Union of terrestrial animals and hatching eggs “
- Delegated Regulation (EU) 2020/689 „Rules for surveillance, eradication programmes, and disease-free status for certain listed and emerging diseases“