I: Certain infectious and parasitic diseases

A15-A19: Tuberculosis

Tuberculosis, often abbreviated as TB, is a group of conditions caused by the bacterium Mycobacterium tuberculosis. These bacteria typically attack the lungs but can also damage other parts of the body. Transmission of these diseases usually occurs through airborne particles when a person with active TB coughs, sneezes, or speaks. Common symptoms include a persistent cough, fever, night sweats, and unexplained weight loss. The progression of the diseases can be slow; and in many cases, the immune system can contain the bacteria, resulting in a latent and non-infectious form of the disease. However, if the immune system fails to contain the bacteria or becomes weakened, the disease can transition into an active form, which can be highly infectious and damaging. Tuberculosis primarily affects the respiratory system, but can also cause health issues in the skeletal, nervous, or circulatory systems.