School of Medicine

Tuberculosis | LSU Wetmore Foundation

Learning about tb


What does the term “TB infection” mean?

"TB infection” means that the bacteria that causes TB is inside the body but is kept inactive. Our body’s defense (the immune system) cannot kill the germ, but it can prevent the germ from doing damage to the body. This means the patient has the bacteria but has no symptoms. However, should the immune system become weakened, the TB germ can cause active disease.

What does the term “TB disease” mean?

TB disease occurs when the body’s immune system no longer keeps the TB germ under control. This weakening of the immune system can occur with aging, illnesses like AIDS, or drug and alcohol abuse. With the onset of active TB disease, the patient begins to experience the symptoms associated with TB such as cough, fever, night sweats, weight loss, and lack of appetite.

What are the risk factors for TB?

Some persons are at higher risk for developing TB, and also more likely to have a complicated course of both disease and treatment. The risk factors include:

  • Being HIV positive or having AIDS
  • Abusing drugs or alcohol
  • Immunecompromised and or on any immune modulator medications

It is important for those with risk factors to have a PPD skin test (the skin test for TB) or the Blood test (IGRA) for detecting TB infection or disease

What is the treatment for TB?

TB is a curable disease. Antibiotics are very effective in killing the TB germ. The treatment is different for TB infection and TB disease. Isoniazid (INH) can be used alone for persons with TB infection, but multiple antibiotics must be given to those persons with active TB disease. This is to prevent the development of drug-resistant TB.

How important is it that ALL of the prescribed medication is taken for the entire period?

Very Important. Taking prescribed medicines for the duration of treatment, even if the patient feels better, is the cornerstone of successful treatment. Taking the medicine for a portion of the specified time only, even if the patient is being treated for TB infection, can cause drug-resistant TB organisms to develop.


What are the complications of TB?

Most TB infections involve the lungs, but without treatment, TB germs can spread from the lungs to other parts of the body. This spread makes people very ill and can cause death. Early detection and treatment are very important in preventing the spread of TB from the lungs to other parts of the body and the spread from person to person.

Can you get TB from the PPD skin test (TST)  or a IGRA BLOOD test for detecting TB

You CANNOT get TB from the PPD skin test (TST) or the IGRA test . The test is an indicator that the body has exposed to the TB germ before. A positive test is recognized by a raised area around the PPD/ TST  injection site or by blood tests results.

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