Prevention of tuberculosis.

Tuberculosis (TB) continues to be a major cause of morbidity and mortality throughout the world. One billion people are infected with the tubercle bacillus, and there are 8 million new cases and 3 million deaths annually. Existing methods of preventing TB are effective, but due to economic and societal constraints, have not been applied throughout the world. Examples of primary prevention include case management and contact investigation, environmental control and vaccination. Secondary prevention is achieved by chemotherapy. The efficiency and use of these various methods will be reviewed, and areas for future study will be discussed.