Elderly people and their tubercle bacilli.
D000368:Aged; D000391:Air Microbiology; D002353:Carrier State; D006801:Humans; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification; D012137:Respiratory System / Q000503:physiopathology; D014376:Tuberculosis / Q000382:microbiology / Q000503:physiopathology; D014397:Tuberculosis, Pulmonary / Q000453:epidemiology / Q000517:prevention & control*; D014481:United States