Tuberculosis (TB) is caused by Mycobacterium tuberculosis (aerobic, non-spore forming bacillus). Active TB is transmitted by aerosolized droplets (sneezing, coughing, talking, etc.) and is highly contagious. ⁠ ⁠ Active disease treatment is divided into two treatment phases, initial and continuation. To avoid treatment failure due to resistance, the preferred initial treatment consists of a 4 drug regimen of rifampin, isoniazid, pyrazinamide, and ethambutol (RIPE). ⁠ ⁠ These 4 drugs are taken for about 8 weeks during the initiation phase. In the continuation phase, the regimen is narrowed based on susceptibilities.