Detection of acid-fast bacilli in clinical specimensTuberculosis (TB) is an infectious disease caused by the bacterium Mycobacterium tuberculosis Complex (MTC). Tuberculosis generally affects the lungs, but can also affect other parts of the body. Most infections do not have symptoms, known as latent tuberculosis. About 10% of latent infections progress to active disease which, if left untreated, kills about half of those infected. The classic symptoms of active TB are a chronic cough with blood-containing sputum, fever, night sweats, and weight loss. AFB stain is used as a primary tool for the diagnosis Pulmonary tuberculosis & other TB as well.