Just a few years ago it was believed that TB was an old disease, and that it was no longer a problem in humans. But now because of such issues as drug resistance and HIV, it has become a major worldwide problem again. Worldwide more people die from the disease than from any other infectious disease. TB is an abbreviation of the word Tuberculosis and is how people often refer to the disease. It is caused by bacteria called Mycobacterium tuberculosis (M.tuberculosis). Bovine TB is a disease caused by similar bacteria called Mycobacterium bovis (M. bovis). Bovine TB mainly affects cattle but can also affect humans. Most of the information on this website refers to the disease in humans.