Latent Tuberculosis Infection

A 44-year-old man who recently immigrated from Peru is found to have induration of 16 mm on a tuberculin skin test. He received bacille Calmette–Guerin vaccine as an infant and is asymptomatic. Chest radiography shows fibronodular opacities in the upper lobe. In another case, a 27-year-old schoolteacher born in the United States has induration of 17 mm on a tuberculin skin test, no symptoms, and a normal chest radiograph. How should these patients' cases be managed?