The purpose of this study is to better understand tuberculosis (TB) and the risk of infection with TB, in Peru. TB is a disease that is caused by bacteria and transmitted through droplets in the air that come from the lungs of an infected person. The risk of infection will be compared between two groups: household members, who live with people having TB that does not respond well to treatment and household members, who live with people having TB that responds well to treatment. Study participants will include 4,500 TB infected people and 22,500 of their household contacts. Study procedures include answering a questionnaire, TB skin tests, blood samples, and a chest x-ray. Individuals with symptoms indicating TB will be asked to provide sputum samples. Individuals with TB will be involved in the study for up to 48 months; household contacts will be involved in the study for 12 months. The knowledge gained from this study will be used to improve tuberculosis control.