[Tuberculosis].

Tuberculosis (TB) continues to be an important public health problem. Currently, 2,100 million people--one third of the world population--are infected by Mycobacterium tuberculosis, with an estimated annual rate of 9.4 million new cases, and 440,000 cases of multidrug-resistant (MDR) TB in 2008; furthermore, cases of extensively-resistant (XDR) TB have been detected in 57 countries.