Around 90% of adults who become infected with tuberculosis never develop the disease. They can control the infection with the help of their immune system. These infected persons are not ill, have no symptoms and are not contagious. The infection is referred to as a latent tuberculous infection (LTBI), as the pathogens are in a dormant form in the body. However, around 5 to 10% of those infected will develop tuberculosis in the course of their lives, which must be treated. The risk of developing the disease is highest in the first two years after infection. For children and immunocompromised people, the risk of infection and disease is significantly higher.