A third of the world's population currently carries the tuberculosis bacillus (TB), but this is a latent form of the disease that is asymptomatic and non-transmissible. Some people develop acute TB due to a deficient immune system. Every year, around nine million people develop the active form of TB, and 1.5 million die from it. 

TB is transmitted through the air when infected people cough or sneeze. Not all infected people become ill, but 10% will develop the disease at some point in their lives. 

Tuberculosis is caused by the bacterium mycobacterium tuberculosis, which is spread through the air when infected people cough or sneeze. The disease most often affects the lungs, but can infect any part of the body, including the bones and nervous system.


Symptoms include a persistent cough, fever, weight loss, chest pain and shortness of breath as death approaches. The incidence of tuberculosis is much higher in people living with HIV, and is a major cause of death among them.


Treatment of uncomplicated tuberculosis takes a minimum of six months. When patients are resistant to the two most powerful first-line antibiotics (rifampicin and isoniazid), they are considered to have multidrug-resistant tuberculosis (MDR-TB). MDR-TB is not incurable, but the treatment required is particularly arduous. It lasts up to two years, with numerous side effects.

Extensively drug-resistant tuberculosis (XDR-TB) is diagnosed when resistance to second-line drugs is added to MDR-TB. Treatment options for XDR-TB are very limited. Two new molecules, bedaquiline and delamanide, have recently become available for patients who have run out of other options.