Mycobacterium bovis is a slow-growing, aerobic bacterium and the causative agent of tuberculosis in cattle. Similar to M. tuberculosis, M. bovis can jump the species barrier and cause tuberculosis in humans.
It is estimated that M. bovis was responsible for more losses among farm animals than all other diseases combined in the first half of the 20th century. Infection happens after bacterium is ingested. It is generally transmitted to humans via infected milk. Actual human infections are rare generally this is because pasteurization kills the bacteria.
The brushtail possum is the main vector in New Zealand. 40% of cows were infected in the 1930s. The risk of people contracting TB from cattle in Great Britain today is very low.
Badgers were identified as carriers 30 years ago. This caused a major battle between animal conservationists and farmers. Findings indicate that the rising incidence of disease can be reversed through rigid application of cattle-based control measures alone.
Other mammals have been found to be infected with M. bovis but it is less common than it is between cattle and badgers. The disease is common among cattle across the world. Most of Europe and several Caribbean countries are virtually free of M. bovis. Australia is officially free of the disease since the successful BTEC program. There was an outbreak in Birmingham, England in 2004.