Transmission:

When people suffers from this disease which is an active pulmonary TB cought, they spread it through the air. A single droplet can transmit the disease, since the infectious dose of it is very low and when other people inhale it only one single bacterium can cause a new infection.
People with prolonged, frequent, or intense contact with the sick people have a high risk of becoming infected.
Transmission can only occur from people with active — not latent — TB [1]. TB can also be transmitted by eating meat infected with TB. Mycobacterium bovis causes TB in cattle. (See details below.)