TB presents in two ways - TB infection and TB disease.
People with TB infection are healthy and able to keep the TB germs "asleep". These folks cannot spread the TB germs. They may never develop TB disease.
People with TB disease are suffering from TB disease. The TB germs are "awake" and doing damage to lungs or other organs of the body. They can spread TB germs when they cough, sing or sneeze.
We can lessen the spread of TB and other germs with good respiratory hygiene.
For more information, please visit the following website: Centers for Disease Control and Prevention (CDC) - Tuberculosis.