Tuberculosis

Scanning electron micrograph of Mycobacterium tuberculosis bacteria

Scanning electron micrograph of Mycobacterium tuberculosis bacteria, which cause TB. 

Credit: NIAID

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. 

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

Basic Research

NIAID supports basic research on Mycobacterium tuberculosis (Mtb), the causative agent of TB, and seeks to understand how the bacterium causes disease in humans. The Institute is accelerating efforts to identify new candidate drugs, vaccines and biomarkers and technologies with diagnostic potential to improve TB diagnosis, treatment, and prevention strategies. NIAID also supports research to map the diversity of genetic drug resistant Mtb and assess what factors influence the occurrence, distribution, and transmission of drug-sensitive and drug-resistant strains of Mtb.

Vaccine Development

Scientists are studying how the TB bacterium evades the immune system to infect people, how it can lay dormant for years and become active at a later stage in life, and why people can have TB disease more than once in their lives. This knowledge will help to find ways to develop vaccines that are able to prime the immune system to recognize Mtb, prevent it from infecting people, or prevent latent infections from progressing to active TB disease.

Diagnosis

NIAID supports the development of new and improved diagnostic tools to more accurately diagnose Mtb infection early TB disease, help optimize therapy by identifying drug-resistant strains, and track the spread of TB in a community. The Institute also encourages researchers to develop tools and identify biomarkers that allow clinicians to rapidly assess how people respond to therapy and to assist in conducting drug and vaccine clinical trials.

Treatment

The emergence of multidrug-resistant (MDR) TB and, more recently, extensively drug-resistant (XDR) TB has intensified the need for new TB drugs. Helping discover and develop those drugs is a top NIAID priority. The Institute supports research to elucidate the mechanisms of drug resistance, identify new TB drug targets and candidate drugs, and evaluate novel TB drugs and optimal drug combinations in preclinical and clinical studies.

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.

Content last reviewed on September 25, 2018