TB is spread through the air from one person to another. The
bacteria are put into the air when a person with TB disease of
the lungs or throat coughs or sneezes. Laughing, singing, or playing
brass or woodwind instruments can also spread the germs in an enclosed
space. People nearby may breathe in these bacteria and become
infected.
When a person breathes in TB bacteria, the bacteria can settle
in the lungs and begin to grow. From there, they move through
the blood to other parts of the body, such as the kidney, spine,
and brain.
TB in the lungs or throat can be infectious. This means that
the bacteria can be spread to other people. TB in other parts
of the body, such as the kidney or spine, is usually not infectious.
People with TB disease are most likely to spread it to people
they spend time with every day. This includes family members,
friends, and coworkers.
