Primary tuberculosis is the initial infection / the first time Micobacterium tuberculosis infects our body. It happens usually in children. If the treatment of that infection is adequate, the bacterias will be totally removed from our body. However, if there is inadequate treatment, the active infection becomes latent infection (bacteria is dormant in our body).
Secondary tuberculosis is reactivation from the latent infection that already exist in our body for a long time. This infection usually happens in adult when their immunity is drop.
If you contact with any person that has tuberculosis infection OR you notice the symptoms (the picture above), PLEASE call your doctor ASAP. Tuberculosis can spread in all of your organ, not only your lung. Be aware !