Hello sir, Tuberculosis is caused by a bacteria called mycobacteria tuberculosis . It spreads through air through droplets. Their are types sir pulmonary and milliary . Milliary is fatal. Tuberculosis has the ability to form secondaries. Primary complex is one which is seen in children less then 14 yrs . People with less immune get it easily . People with primary complex are susceptible to TB when they grow up. A proper treatment is required for tuberculosis and it is curable.