TB is spread through the air from one person to another. The bacteria are spread when a person with active TB disease of the lungs or throat coughs or sneezes. People nearby can breathe in the TB germs that are in the air and may become infected.
You CANNOT get TB from sharing a drinking glass with a person who has TB or touching a doorknob after someone with TB has used it. Also, once a person with TB is taking medication for treatment, he or she quickly becomes non-contagious. Additionally, once treatment has begun, he or she can quickly resume their normal life without fear of spreading TB to others.