Tuberculosis (TB) is an infection caused by slow-growing bacteria that grow best in areas of the body that have lots of blood and oxygen, like the lungs. This is called pulmonary TB. But TB can also spread to other parts of the body, which is called extrapulmonary TB. Treatment usually takes about 6 to 9 months to treat TB, but some TB infections need to be treated for up to 2 years.
Pulmonary TB (in the lungs) is contagious. It spreads when a person who has active TB breathes out air that has the TB bacteria in it and then another person breathes in the bacteria from the air. An infected person releases even more bacteria when he or she does things like cough or laugh.
If TB is only in other parts of the body (extrapulmonary TB), it does not spread easily to others.
Some people are more likely than others to get TB. This includes people who:
- Have HIV or another illness that weakens the immune system.
- Have close contact with someone who has active TB, such as living in the same house as someone who is infected with TB.
- Care for a patient who has active TB, such as doctors or nurses.
- Live or work in crowded places, such as prisons, nursing homes, or homeless shelters, where other people may have active TB.
- Have poor access to health care, such as homeless people and migrant farm workers.
- Abuse drugs or alcohol.
- Travel to or were born in places where untreated TB is common, such as Latin America, Africa, Asia, Eastern Europe, and Russia.
It is important for people who are at a high risk for getting TB to get tested once or twice every year.
