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Facts About Tuberculosis

What is Tuberculosis?

Tuberculosis (TB) is an airborne disease caused by a bacteria called Mycobacterium tuberculosis, a germ that primarily effects the lungs but can also effect other organs. People who are infected with TB do not feel sick, do not have any symptoms and are not contagious unless and until their infection develops into TB disease.

How Do You Get TB?

TB is spread through the air. Whenever someone with infectious TB sneezes, coughs, or talks, TB bacteria may be released into the air. Someone nearby may inhale the TB bacteria, at which point they may become infected with TB. Once inside the body, the TB bacteria can be made inactive, or it can settle in the lungs and begin to grow. The TB bacteria also can spread to other parts of the body such as the spine, brain and kidney.

The Difference Between TB Disease & TB Infection

Symptoms of TB

A bad cough lasting longer than two weeks

Coughing up blood

Chest pains

Fatigue or weakness


Weight & appetite loss

Sweating at night


Approximately, 10 percent of people infected with the TB germ will develop TB disease at some point in their lives. The risk is greatest during the first two years after being infected. The risk is also greatest for persons who are HIV-positive or who have other clinical conditions that effect the immune system. The remaining 90 percent of those who are infected have no symptoms, other than a positive reaction to the tuberculin skin test, and will not develop TB disease. They have what is known as latent TB infection. They are not infectious and cannot transmit TB to anyone because their immune systems stop the infection.

If an infected person's body is not able to make the TB germ inactive, they are said to have TB disease. Those with TB disease in their throat or lungs are infectious and can easily spread the TB bacteria.

Should You Get Tested for TB?

You should get tested for TB infection if:
  • You have spent time with someone with infectious TB.
  • You live or work in a congregate environment. Such environments include some hospitals, nursing homes and most homeless shelters, prisons, jails and migrant farm camps.
  • You think you might have TB disease.
  • You are from a country where TB disease is common.
  • You have HIV infection or another condition that places you at high risk for TB disease.
  • You inject drugs and/or share needles.

Who Is At High Risk of TB?

  • People living with HIV or other diseases that weaken the immune system.
  • People who became infected with TB within the last two years.
  • People who share needles and/or inject drugs.
  • People who have had close contact with someone who has infectious TB.