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.

Can tuberculosis be cured?

In the 20th century, TB was a leading cause of death in the United States. Today, most cases are cured with antibiotics. But it takes a long time. You have to take medications for at least 6 to 9 months.

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.

A latent or active TB infection can also be drug-resistant, meaning certain medications don’t work against the bacteria.

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

If you have any of these symptoms, see your doctor to get tested. Get medical help right away if you have chest pain.

Tuberculosis Causes

Tuberculosis is caused by bacteria that spread through the air, just like a cold or the flu. You can get TB only if you come into contact with people who have it.

Tuberculosis Risk Factors

You could be more likely to get TB if:

• A friend, co-worker, or family member has active TB.
• You live in or have traveled to an area where TB is common, like Russia, Africa, Eastern Europe, Asia, Latin America, and the Caribbean.
• You’re part of a group in which TB is more likely to spread, or you work or live with someone who is. This includes homeless people, people who have HIV, people in jail or prison, and people who inject drugs into their veins.
• You work or live in a hospital or nursing home.
• You’re a health care worker for patients at high risk of TB.
• You’re a smoker.

A healthy immune system fights the TB bacteria. But you might not be able to fend off active TB disease if you have:

• HIV or AIDS
• Diabetes
• Severe kidney disease
• Head and neck cancers
• Cancer treatments such as chemotherapy
• Low body weight and poor nutrition
• Medications for organ transplants
• Certain drugs to treat rheumatoid arthritis, Crohn’s disease, and psoriasis

Babies and young children also have higher chances of getting it because their immune systems aren’t fully formed.

Tuberculosis Transmission

When someone who has TB coughs, sneezes, talks, laughs, or sings, they release tiny droplets that contain the germs. If you breathe in these germs, you can get it.

TB isn’t easy to catch. You usually have to spend a long time around someone who has a lot of the bacteria in their lungs. You’re most likely to catch it from co-workers, friends, and family members.

Tuberculosis germs don’t thrive on surfaces. You can’t get it from shaking hands with someone who has it or by sharing their food or drink.

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.

Like any medication, TB drugs can have side effects.

Common isoniazid side effects include:

• Numbness and tingling in your hands and feet
• Upset stomach, nausea, and vomiting
• Loss of appetite
• Weakness

Ethambutol side effects may include:

• Chills
• Painful or swollen joints
• Belly pain, nausea, and vomiting
• Loss of appetite
• Headache
• Confusion

Some pyrazinamide side effects include:

• Lack of energy
• Nausea and vomiting
• Loss of appetite
• Muscle or joint pain

Common rifampin side effects include:

• Skin rash
• Upset stomach, nausea, and vomiting
• Diarrhea
• Loss of appetite
• Inflamed pancreas

Tuberculosis Complications

Tuberculosis infection can cause complications such as:

• Joint damage
• Lung damage
• Infection or damage of your bones, spinal cord, brain, or lymph nodes
• Liver or kidney problems
• Inflammation of the tissues around your heart

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.

Tuberculosis vaccine

Children in countries where TB is common often get the BCG vaccine. It isn’t widely used in the United States, and it doesn’t always protect against infection. Doctors recommend it only for children living with someone who has an active TB infection with a very drug-resistant strain or who can’t take antibiotics.

Other vaccines are being developed and tested.

Tuberculosis Outlook

Your outlook depends on several things, including your overall health, how severe the infection is, and how well you follow your doctor’s directions on treatment. In the United States, experts estimate that treatment works in more than 95% of cases.

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