Human tuberculosis (TB) resulting from Mycobacterium tuberculosis and occasionally Mycobacterium bovis infection had been in decline for many decades, in the western world, owing to the advent of effective anti-microbial therapies and good public health programs that have controlled the spread of the disease. Nonetheless, there are currently in excess of one billion indivrduals infected with M. tuberculosis. TB accounts for approx 25% of all preventable deaths worldwide, resulting in more than 3.5 million deaths annually (1).