Tuberculosis (TB) is a contagious disease caused by infection with Mycobacterium tuberculosis (Mtb) bacteria. It is spread through the air when a person with TB disease of the lungs or throat coughs, speaks or sings, and people nearby breathe in these bacteria and become infected. 

TB typically affects the lungs, but it can also affect other parts of the body, including the kidney, spine and brain. Not everyone infected with TB bacteria becomes sick. People who have latent TB infection have the TB bacteria in their bodies but are not sick and cannot spread the bacteria to others. Individuals with active TB disease, however, are sick and may also be able to transmit the bacteria to others. Many people with latent TB never develop active TB disease. For people with weakened immune systems, such as those living with HIV infection, the risk of developing TB disease is much higher than for those with normal immune systems. Both latent TB infection and active TB disease can be treated. Without treatment, latent TB infection can progress to TB disease, and without proper treatment, TB disease can kill.

Why Is the Study of Tuberculosis a Priority for NIAID?

Tuberculosis is the leading infectious cause of death worldwide. In 2017, 10 million people became ill with TB, and 1.6 million people died of TB disease including 230,000 children, according to the World Health Organization. Over the past 200 years, TB has claimed the lives of more than one billion people---more deaths than from malaria, influenza, smallpox, HIV/AIDS, cholera, and plague combined. Although TB treatment exists, drug resistance is a continued threat.

How Is NIAID Addressing This Critical Topic?

NIAID supports and conducts basic, translational and clinical research to better understand TB and expedite the development of innovative new tools and strategies to improve diagnosis, prevention and treatment of TB. 

NIAID Strategic Plan for Tuberculosis Research

TB is the world’s leading infectious cause of death. In its strategic plan, NIAID details five strategic priorities for building on research advances to develop the knowledge and tools to end TB globally.

Related Public Health and Government Information

To learn about risk factors for tuberculosis and current prevention and treatment strategies visit the MedlinePlus tuberculosis site.

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