Tuberculosis

Tuberculosis (TB) is caused by bacteria (Mycobacterium tuberculosis) that most often affect the lungs. About one-quarter of the world's population has been infected with TB, most of whom are not ill and cannot transmit TB.

TB is the world's leading cause of death from a single infectious agent. In 2023, 1.25 million people died from TB. This includes 161 000 individuals who were also living with HIV.

Most people infected with TB bacteria do not have TB disease, but they can develop TB. The lifetime risk of falling ill with TB is on average about 5-10%. However, persons with compromised immune systems, such as people living with HIV, malnutrition or diabetes, or people who use tobacco, have a much higher risk of developing TB disease. When a person develops TB disease, they may only have mild symptoms, and some have no symptoms at all. This can lead to delays in seeking care and continued transmission of the bacteria to others.

Tuberculosis (TB) often affects the lungs and can lead to several symptoms. Common signs of active TB include a persistent cough, sometimes with mucus or even blood. People might also experience chest pain, weakness or fatigue, unintentional weight loss, fever and night sweats. It's important to remember that these symptoms can be mild at first and develop slowly. If you experience these signs, seeking medical attention is crucial for diagnosis and treatment of TB.

TB is spread from person to person through the air. When people with lung TB cough, sneeze or spit, they propel the TB germs into the air. A person needs to inhale only a few of these germs to become infected. People with untreated TB can infect up to 10–15 other people through close contact over one year.

Tuberculosis is mostly curable but without proper treatment about two thirds of people who get TB will die. Since 2000, about 79 million lives have been saved through effective diagnosis and treatment. Most people who have TB disease can be cured with a course of 4 antimicrobials lasting 6 months, or even 4 months in some cases. Information, supervision and patient support by a health worker or trained volunteer are key to a successful outcome.

Tuberculosis is largely preventable. TB preventive treatment (TPT) can be given to avoid progression from TB infection to disease in people at risk. TB screening and action on poverty, malnutrition, HIV, diabetes and tobacco are some of the population measures that can reduce TB burden. The currently licensed vaccine – BCG – protects from severe forms of TB and from deaths from TB, especially in young children.