Tuberculosis

Tuberculosis is a type of infectious diseases that spreads through air. The primary organ that is affected in human body is the lung. But almost all other systems like bones, joints, brain, skin, blood and lymphatic system can be the target of the disease.

Tuberculosis in human population is primarily caused by a small rod shaped bacterium – Mycobacterium tuberculosis. There are certain other agents, which can lead to tuberculosis also – Mycobacterium bovis (mainly affects cattle), Mycobacterium microti, Mycobacterium africanum, Mycobacterium canetti, Mycobacterium avium intracellulare (infects the patients having AIDS).

Robert Koch, a German physician first isolated tuberculosis bacillus from the sputum of a patient having chronic cough. Later he was awarded Nobel Prize for his discovery.

During the 19th Century, more than 25% of the deaths in the European continent were caused by Tuberculosis. Later, as the sanitation and standard of living was improved, the number of cases started to decrease.

According to the WHO report, at least one person is getting infected by tuberculosis each second and almost one third of the total human population is infected with tuberculosis bacilli. It is also mentioned that nearly 1.6 million deaths were directly related to the disease in 2005 globally. Most of the cases were being reported from the South-East Asia region. It comprises more than 34% of the total incidence of tuberculosis. The incidence of HIV/AIDS in this area also accounts for the large number of tuberculosis cases. Poverty, poor sanitation, lack of proper health care services and emergence of multi-drug resistant tuberculosis bacilli add to the graveness of the disease. Tuberculosis has become pandemic throughout the world.

Although, Mycobacterium is the main causative agent of tuberculosis, some other mycobacteria also contribute to the total number of cases. These are called Atypical Mycobacterium. Mycobacterium bovis, Mycobacterium microti, Mycobacterium africanum, Mycobacterium canetti and Mycobacterium avium intracellulare fall in this category.

When a person having the infection talks loudly, sneezes, spits or coughs, he spreads tuberculosis bacteria in the air. A person previously untouched by this bacillus receives the organism during inhalation. After that, the organism gets localized in the lungs and starts multiplying. Eventually the full blown disease occurs. It is not necessary that all the persons getting infected will develop the disease. The immune system of our body localizes the organisms inside a shell. In a later date, when the immune system becomes weak, the tuberculosis bacilli may start multiplying.
Tuberculosis wikipedia
http://en.wikipedia.org/wiki/Tuberculosis