Tuberculosis is a germ infection caused by Mycobacterium tuberculosis which generally affects the lungs, but it can also affect kidneys, lymph nodes, spine, intestinal tract and brain.
Tuberculosis is spreading by air, if an infected person coughs sneezes or shouts, the germs spreading into the air. By inhaling them other people get infected.
After the discovery of the BCG vaccine and of the antibiotic treatment of TB, the number of TB cases declined in the early 1980's and experts thought that the disease would be eradicated by 2010. But between 1985 and 1991 more and more cases of TB were discovered in US. Since 1992, in US, the number of reported cases declined continuously and so, in 2004 there was a 46% drop of reported cases from 12 years earlier.
One of the reason why tuberculosis has spread so quickly lately is the increased number of patients infected with HIV. HIV leads to a weakened immune system, and so, TB has a free way to develop, and passes quickly from the primarily stage to the secondary stage.
The germ can reactivate if a person has a weakened immune system like in the cases of AIDS, post surgery, after other infections, in miners and foundry workers, and in those who have scars of healed tuberculosis.
Also, the risk of catching TB increases with the frequency of contacting other infected people, with miserable living conditions and with poor nutrition.
Another factor that helps tuberculosis to spread is the fact that some patients do not finish their antibiotic treatment. This treatment must be followed a long period of time (6 to 9 months), and often, if patients feel better they interrupt the treatment, believing that they are cured, but this is only an illusion, because TB germ is still alive, can activate instantly and spread itself to other healthy people. This fact also could lead to the mutation of the germ that becomes multi drug resistant, and does not respond properly to the known treatment, and so, scientists must discover new efficient drugs.
Nowadays people have businesses to take care of, and they have to travel a lot. Tourism as well has developed and gained a lot of interested people in this activity. All these activities can lead to a contamination with the TB bacterium and its transportation back home where healthy people are.
In preventing Tb from spreading, governments need to develop special international measures and communicate with people. Also, regular controls should be made along with the education for health.