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 TUBERCULOSIS

Tuberculosis is a contagious bacterial infection caused by Mycobacterium tuberculosis, which mainly affects the lungs, but it might spread to any organ.

M. tuberculosis can be transmitted by breathing in air droplets or aerosols from a cough or sneeze of an infected person. The bacteria stay and proliferate in the lungs.

A type of delayed reaction produces activated macrophage nodules in the lungs, called tubercles. However, bacteria tend to survive and even proliferate in the tubercles. Then, an acute infection is produced, which may lead to the destruction of the pulmonary tissue; the spread of the bacteria to other parts of the body; or death. 35