Re-emergence of tuberculosis: strategies and treatment.

Tuberculosis (TB) was declared a global emergency by the WHO in 1993. Approximately one third of the world's population is infected with Mycobacterium tuberculosis. Despite the availability of effective chemotherapy, 3.5 million TB deaths occur each year. In addition to this human cost, TB also represents a significant economic burden for developing countries. The worldwide spread of TB is mainly caused by the emergence of multidrug-resistant (MDR) M. tuberculosis strains, thus underlining the need for novel antimycobacterial drugs with improved efficacy. Research in TB chemotherapy, as well as in vaccine development, has entered an intense phase in an attempt to combat this disease.