The tubercle bacillus or Mycobacteria tuberculosis causes tuberculosis, it can be found everywhere around us, tapwarer, grass, mud, hay, rubber tubing. Usualy they do not cause human infection, when they do there are other factors that influence and create proper conditions such as: poor ventilation, dusty atmosphere, poor and low protein diet, migration, overcrowding, grief.

Tuberculosis affects especially people with uprooted families, with poor economic conditions and bad or hard working in inproper conditions,in shoddy accomodation. Tuberculosis was described among city builders and devastated Europe, during the era of mass production, slum cities and subsistence wages.

Those who were infected with tuberculosis and eventually died of it were immigrants, industrial workers and the homeless . Rich, well-nourished people became infected too, but as in all times they could afford medical care and treatments, so they were cured. Famous artists, musicians and poets succumbed to tuberculosis, because they weren't paying proper attention to the disease and to its therapy.

Overwork, poor diet and damp, airless accomodation had increased importance in developing tuberculosis. The bacteria may be spread by coughing, sneezing and talking, living in the same house with a person with tuberculosis means real chances of developing the disease. Tuberculosis is not spread by clothes or bedding. Mycobacteria are highly susceptible to ultra violet radiation and transmission rarely occurs out-of-doors in daylight. Mortality from tuberculosis had an increased rate among immigrants from the Indian subcontinent and Irish.

The soil is everything; the germ is nothing is what Louis Pasteur said on his deathbed refering to Mycobacteria tuberculosis and other bacterias. Robert Koch, a German scientist was the one to discover the tubercule bacillus. That time tuberculosis was a growing problem, a large part of the population was infected and annual deaths were inregistrated. Epidemic pandemies were observed during that period. And that's why it was absolutely imperios to develop a vaccine and antituberculous drugs.

Although by that time the introduction of antituberculous drugs and BCG was not of great help, the rate of death and infections was constant in spite of those important discoveries. Only after a while, with the development of the cities infrastructure and technologies and possibilities of cleaning and desinfection there were observed the decrease of tuberculous mortality, in US. and United Kingdom. Other countries and continents such as: Philippines, Asia, Greece continued to have high rates of tuberculosis.

Tuberculosis affects many people every year, worldwide, in countries with a higher prevalence of HIVcases tuberculosis affects more people. A percent of those people will develop the active tuberculsis at one time in their life, for those with positive HIV the chances of developing tuberculosis are even higher, because of the damages produced in their immune system.