Tuberculosis is a serious infection caused most commonly by the Mycobacterium tuberculosis bacterium or one of three other organisms of the Mycobacterium genus. Tuberculosis primarily affects the lungs, but the infection can attack any part of the body. If left untreated, tuberculosis can cause lung damage, meningitis, and even death; the World Health Organization reported 1.3 million deaths due to tuberculosis in 2008. Those at highest risk for tuberculosis include those with weakened immune systems and those in areas of the world with poor nutrition and poor access to health care. Most...