Mycobacterium tuberculosis, or tuberculosis (TB), is an infectious disease that usually attacks the lungs, but can attack almost any part of the body. TB is spread through the air. People who have been diagnosed with TB harbor the bacterium without symptoms but many develop active TB disease. Every year, about 8 million people worldwide develop active TB and 3 million die from it.
In the 1940s, scientists discovered the first of several drugs now used to treat TB. As a result, TB slowly began to disappear in the United States, but it came back. Between 1985 and 1992, the number of TB cases increased. The country became unworried about TB and funding of TB programs was decreased. However, with increased funding and attention to the TB problem, we have had a steady decline in the number of persons with TB, but it is still a problem. More than 16,000 cases were reported in 2000 in the United States.
Tuberculosis is an airborne bacterium. When someone infected with TB coughs, sneezes, laughs, sings, and even talks, the germs spread through the air. Whoever breathes in the germs has a great chance of becoming infected by the TB. Tuberculosis isn't easy to catch, however. You would have to be close to a TB infected person for a long period of time. Tb is usually spread between family members, close friends, and people who work or live together. People who become infected with TB do not develop the disease sometimes because their body's defenses protect them. Experts believe that about 10 million Americans are infected with TB and only about 10 percent of those people actually develop the disease. The other 90 percent will never get sick or spread the TB, but can develop it later in life.
Anyone can get TB, but there are groups of people that are at a higher risk of getting active TB.