Tuberculosis is an infectious and contagious disease that usually affects the lungs but can also affect other parts of the body like brain(meningitis), lever & kidneys, bones etc. The Mycobacterium tuberculosis bacterium causes TB. It spreads through the air when a person with TB (whose lungs are affected) coughs, sneezes, spits, laughs, or talks. Tb can affect both children as well as adults.

Tuberculosis could be Latent and active.
* In Latent TB - bacteria remain in the body in an inactive state. They cause no symptoms and are not contagious, but they can become active later.