PULMONARY TUBERCULOSISWHAT IS TUBERCULOSIS?
Tuberculosis (TB), a chronic bacterial infection, causes more deaths worldwide than any other infectious disease - killing more adults each year than AIDS and malaria combined. TB is spread through the air and usually infects the lungs (pulmonary TB), although other organs are sometimes involved. Some 1.7 billion people - one-third of the world's population - are infected with the predominant TB organism, Mycobacterium tuberculosis. This includes between 10 and 15 million people in the United States.

Most people infected with M. tuberculosis never develop active TB. However, in people with weakened immune systems, especially those infected with the human immunodeficiency virus (HIV, the cause of AIDS), TB organisms may overcome the body's defenses, multiply, and cause active disease. Each year, 8 million people worldwide develop active TB and 3 million die.
The TB crisis is intensified by the emergence of disease caused by multidrug-resistant organisms. Infections caused by these organisms may result in an essentially incurable form of the disease. The World Health Organization estimates that more than 50 million people worldwide may be infected with drug-resistant strains of TB.
Standard medical treatment with antibiotics is usually effective in managing TB. Successful treatment depends on close cooperation between the patient and physicians and other health care workers. Patient education is essential, and many doctors opt for supervised, directly observed therapy (DOT). (National Institutes of Health)