Tuberculosis is known to exist even before the year 2000BC, and writings from Egypt and Babylon mention it. Until the discovery of the antibiotic treatment and of the BCG vaccine, TB made a lot of victims during a global epidemic.

There are some germs belonging to the Mycobacterium family, referred to as atypical tuberculosis. Generally these organisms live among other germs in the body and do not cause any harm, but sometimes they can lead to an infection or even to the typical tuberculosis.

Healthy persons receive the infection if living or working in the same place with the infected person. By coughing, shouting or sneezing, the infected person spreads the germs into the air, and others inhale them. Shaking hands or touching clothes does not infect others.

Another form of tuberculosis is transmitted by drinking unpasteurized milk. The responsible bacterium for this form of TB infection is called Mycobacterium bovis. Years before, this bacterium was a major cause of TB in children, but now since most milk is pasteurized (a heating process that kills the bacteria) it does not cause TB any more.

When a person gets infected with TB, the germ enters the lungs and causes a local infection. The lymph nodes are connected to the lymphatic system and could get enlarged. Using the lymphatic system the infection could spread in all the body and affect all the organs. Sometimes the immune system stops the infection by creating a scar tissue all around the infected area, and so the infection becomes inactive. If at some time the immune system becomes weakened due to another infection or to cancer the TB germs could pass by the scar tissue and spread the infection in the body.

In preventing the infection with TB some countries vaccinate their children with the BCG vaccine.This is a vaccine prepared of a weakened Tb germ, and it is considered to be the most effective vaccine in preventing childhood cases of TB.

In treating TB, doctors use a combination of antibiotics because using only one drug could lead to the bacterial resistance to this drug. The drugs used nowadays are: isoniazid, rifampin, pyrazinamide, and ethambutol, in different combinations.

Generally if the treatment is followed all the way, a person can heal without problems, and reintegrate within the society in about 6 to 9 months.