| Abstrakt: |
Following the pioneering work (1882) of Robert Koch on the etiology of mycobacterial tuberculosis in humans, similar findings were made in many animal species. Especially dairy cows were frequently infected, but confusion arose about the zoonotic significance of bovine tuberculosis. This was due to the fact that two agents were involved in human infections. Typical ‘consumption’ (lung tuberculosis) appeared to spread from man to man, mainly by air, being caused by Mycobacterium tuberculosis, a species rarely found in animals, whereas strains identified as Mycobacterium bovis infected many different animal species, including man. Disease caused by the latter group spreads orally and affects preferably, though not exclusively, the intestinal tract of children. Although percentages did not remain stable and varied widely between countries and even regions, it can be stated that, overall, in the first half of the previous century, about ten percent of human infections in Western Europe were caused by M. bovis strains. They were not easily differentiated from M. tuberculosis. Some leading specialists even speculated that the one type was able to evolve into the other. Despite of these uncertainties, a comprehensive and long-lasting programme was set up to eliminate tuberculosis from cattle. This was based on tuberculination, an in vivo diagnostic test using allergic reactions following injections of killed TB bacilli. Applications of these preparations, called tuberculins, introduced in the first years of the previous century, turned out to be very reliable. Considerable efforts were made to motivate all parties involved to create an obligatory animal identification system, to restrict commercial transactions of infected animals, to test all animals of a certain age, and to provide financial bn help, especially when animals needed to be slaughtered. After more than half a century, this dreadful endemic disease was practically eradicated from cattle in Belgium. Since 2003, the country is officially free. In retrospect, it can be concluded that this huge effort succeeded partly because it was never really evident that bovine infections were responsible for only a minority of human cases. This illustrates the essentially antropocentric character of veterinary medicine. Anyhow, the successful anti-tuberculosis campaign created goodwill and facilitated in this way subsequent programmes to eradicate another endemic bovine infection, notably brucellosis. It laid the basis for official animal health organization, still operative at this moment. [ABSTRACT FROM AUTHOR] |
