Nearly 2 million people die from tuberculosis each year, mainly in the poorest countries.
The pathogen, Koch's bacillus, can pass easily by aerial infection from one individual to another. The spread of the disease, favoured by the AIDS epidemic and the appearance of multi-resistant strains, has led WHO to make tuberculosis control one of the world's main health priorities. The existing treatment, which combines several antibiotics prescribed for a period of 6 to 8 months as against 18 months to 2 years still only a few years ago has proved efficient in 95 % of cases. However, this efficacy is called into question by the low adherence of patients to treatment, particularly in the most deprived areas, which are often indeed the worst hit by the disease. In spite of the WHO recommendation to administrate the treatment under the direct supervision of health care personnel who play the role of supporter (DOT : Directly observed therapy), more than 10% of patients stop the treatment before the prescribed period. This defaulting, along with irregularity in taking the medicines, creates increased risk of serious relapse, which opens the way to a rise in transmission events and the emergence of bacteria resistant to the prescribed antibiotics.