Tuberculosis (often called TB) is an infectious disease that usually attacks the lungs, but can attack almost any part of the body. Tuberculosis is spread from person to person through the air. When people with TB in their lungs or throat cough, laugh, sneeze, sing, or even talk, the germs that cause TB may be spread into the air. If another person breathes in these germs there is a chance that they will become infected with tuberculosis. Repeated contact is usually required for infection. It is important to understand that there is a difference between being infected with TB and having TB disease. Someone who is infected with TB has the TB germs, or bacteria, in their body. The body’s defenses are protecting them from the germs and they are not sick. Someone with TB disease is sick and can spread the disease to other people. A person with TB disease needs to see a doctor as soon as possible. It is not easy to become infected with tuberculosis. Usually a person has to be close to someone with TB disease for a long period of time. TB is usually spread between family members, close friends, and people who work or live together. TB is spread most easily in closed spaces over a long period of time. However, transmission in an airplane, although rare, has been documented. Even if someone becomes infected with tuberculosis, that does not mean they will get TB disease. Most people who become infected do not develop TB disease because their body’s defenses protect them. TB is an increasing and major world wide problem, especially in Africa where the spread is facilitated by AIDS. It is estimated that nearly 1 billion people will become newly infected, over 150 million will become sick, and 36 million will die worldwide between now and 2020 if control is not further strengthened. Each year there are more than 8.7 million cases and close to 2 million deaths attributed to TB; 100,000 of those 2 million deaths occur among children.