Tuberculosis (TB)

 

What Is Tuberculosis?

Tuberculosis (TB) is a contagious infection that usually attacks your lungs. It can also spread to other parts of your body, like your brain  and spine. A type of bacteria called Mycobacterium tuberculosis causes it.

Tuberculosis Types

A TB infection doesn’t always mean you’ll get sick. There are two forms of the disease:

Latent TB. 

You have the germs in your body, but your immune system keeps them from spreading. You don’t have any symptoms, and you’re not contagious. But the infection is still alive and can one day become active. If you’re at high risk for re-activation -- for instance, if you have HIV, you had an infection in the past 2 years, your chest X-ray is unusual, or your immune system is weakened -- your doctor will give you medications to prevent active TB.  

Active TB.

The germs multiply and make you sick. You can spread the disease to others. Ninety percent of active cases in adults come from a latent TB infection.

Tuberculosis Signs and Symptoms

Latent TB doesn’t have symptoms. A skin or blood test can tell if you have it.

Signs of active TB disease include:

• A cough that lasts more than 3 weeks
• Chest pain
• Coughing up blood
• Feeling tired all the time
• Night sweats
• Chills
• Fever
• Loss of appetite
• Weight loss

Tuberculosis Tests and Diagnosis

There are two common tests for tuberculosis:

Skin test.

This is also known as the Mantoux tuberculin skin test. A technician injects a small amount of fluid into the skin of your lower arm. After 2 or 3 days, they’ll check for swelling in your arm. If your results are positive, you probably have TB bacteria. But you could also get a false positive. If you’ve gotten a tuberculosis vaccine called bacillus Calmette-Guerin (BCG), the test could say that you have TB when you really don’t. The results can also be false negative, saying that you don’t have TB when you really do, if you have a very new infection. You might get this test more than once.

Blood test. 

These tests, also called interferon-gamma release assays (IGRAs), measure the response when TB proteins are mixed with a small amount of your blood.

Those tests don’t tell you if your infection is latent or active. If you get a positive skin or blood test, your doctor will learn which type you have with:

A chest X-ray or CT scan to look for changes in your lungs

Acid-fast bacillus (AFB) tests for TB bacteria in your sputum, the mucus that comes up when you cough.

Tuberculosis Treatment

Your treatment will depend on your infection.

• If you have latent TB, your doctor will give you medication to kill the bacteria so the infection doesn’t become active. You might get isoniazid, rifapentine, or rifampin, either alone or combined. You’ll have to take the drugs for up to 9 months. If you see any signs of active TB, call your doctor right away.
• A combination of medicines also treats active TB. The most common are ethambutol, isoniazid, pyrazinamide, and rifampin. You’ll take them for 6 to 12 months.
• If you have drug-resistant TB, your doctor might give you one or more different medicines. You may have to take them for much longer, up to 30 months, and they can cause more side effects.

Whatever kind of infection you have, it’s important to finish taking all of your medications, even when you feel better. If you quit too soon, the bacteria can become resistant to the drugs.

Tuberculosis Prevention

To help stop the spread of TB:

• If you have a latent infection, take all of your medication so it doesn’t become active and contagious.
• If you have active TB, limit your contact with other people. Cover your mouth when you laugh, sneeze, or cough. Wear a surgical mask when you’re around other people during the first weeks of treatment.
• If you’re traveling to a place where TB is common, avoid spending a lot of time in crowded places with sick people.