Tuberculosis is one of the infectious diseases that had a huge impact on the health of the populations since the XVIIth century, and this remains true for most of the people in the World in 2012. Its natural story involves: contamination (inhalation of infectious particles, the Pflügge droplets, originating from a patient with bacillary tuberculosis); primary infection (remarkable by initial unresponsiveness of the immune system, followed by strong cellular immunity development within 3 to 9 weeks); latent tuberculosis infection, non-contagious and totally asymptomatic, with efficient control of tuberculosis bacilli replication, lasting for life in more than 90% of cases; and less frequently, tuberculosis disease in patients with insufficient immunity, including children less than 5 years, immunocompromised, and patients recently infected.