When you have signs and symptoms of a lung infection, such as a chronic cough, weight loss, fever, chills, and weakness, that may be due to TB or a nontuberculous mycobacterial (NTM) infection; when you have a positive TB screening test and you are in a high-risk group for progressing to active disease; when you have a skin or other body site infection that may be due to mycobacteria; when you are undergoing treatment for TB.