How TB Spreads  

TB spreads when people with the disease cough tiny droplets containing TB bacteria into the air, and other people breathe them in. 

In overcrowded, poorly ventilated areas the germs are more easily spread from the TB sufferer to another person. People living in overcrowded conditions are more prone to being infected. 
The TB bacilli are so small that they are invisible to the human eye. The germs are in the person's sputum (spit). They can only be seen under a microscope.

When one person is sick with TB, and not properly treated, that person will likely infect ten to fifteen others every year. Obviously, the more people who are coughing up TB germs at any given time, the more people will become infected. The best way to break this cycle of infection and disease is to cure infectious TB patients the first time around.

The germs can also be spread by dust that has been contaminated by the spitting from an infectious person.

Gif thanks to the Lupin Group

Another less common way of spreading this disease is by drinking infected cow's milk - this is called the bovine strain. This usually results in tuberculosis in other parts of the body and not in the lungs.

You should only drink pasteurized milk as this ensures that it is free of disease. Do not buy milk from private sellers as they do not pasteurize their milk and you run the risk of infection.

TB is not only a disease of the lungs.

This disease can affect any part of the body including the kidneys, the brain, the spine and other vital organs. Children are more at risk of getting TB in different parts of the body because their immune systems are not yet fully developed.