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What is tuberculosis?

Tuberculosis (TB) is a chronic bacterial infection that usually infects the lungs, although other parts of the body are sometimes involved. There are two stages of TB: infection and disease.

  • One-third of the world’s population is thought to be infected with TB.
  • Only 5 to 10 percent of the U.S. population tests positive for TB.
  • Tuberculosis is an old disease — the study of it dates back to the 1020s.

What is tuberculosis (TB) infection?

TB infection occurs if your child has a small number of TB germs in his body, but his immune system prevents the germs from causing any problems.

If your child has TB infection, usually he:

  • doesn’t feel sick
  • has a positive skin test reaction
  • can develop TB disease if he does not receive treatment for his TB infection

What is TB disease?

TB disease occurs when your child has a large number of TB germs living in his body and the germs are causing harm. Usually your child will feel sick, and he often can spread TB germs to others. TB disease can be found in any part of the body but it usually affects the lungs.

Common symptoms of TB disease are:

  • coughing
  • fever
  • loss of appetite
  • weight loss
  • weakness
  • night sweats
  • feeling very tired

If not treated properly, TB disease can be fatal. TB disease was once the leading cause of death in the United States.

Who is at risk for developing TB?

Your child is at risk for TB if he has ever had contact with a person who has had TB infection. Some groups of people who are at increased risk for TB include:

  • people born in less industrialized areas (Latin America, Asia, Africa)
  • medically underserved population usually in urban areas including children under the age of 4
  • homeless people
  • people who abuse alcohol
  • people who use intravenous drugs
  • the elderly
  • people in group settings, such as nursing homes
  • people with weak immune systems (especially those with HIV infection)
  • people with other medical risk factors such as diabetes and severe kidney disease

How is TB spread?

TB is spread from one person to another through the air. TB germs are launched into the air when a person with TB disease of the lungs coughs or sneezes.

TB in the lungs or throat can be spread to other people. TB in other parts of the body, such as the kidney or spine, is usually not infectious.

If your child has TB disease, he is most likely to spread it to people he spends time with every day, including family members and friends.

How does someone get infected with TB?

When someone with TB disease of the lungs coughs or sneezes near your child, your child can breathe in the TB germs and become infected. When this happens, the bacteria settle in your child’s lungs and begin to grow. From there, they can move through the blood to other parts of his body, such as the kidney, spine and brain.

What is BCG?

BCG is a vaccine for TB. This vaccine is not widely used in the United States, but it is often given to infants and small children in other countries where TB is common. BCG vaccine does not always protect people from getting TB.

Tuberculosis (TB) | Diagnosis & Treatments

How is TB diagnosed?

TB is usually diagnosed with a simple skin test. During this test, a doctor or nurse injects a small amount of testing fluid (called tuberculin or PPD) just under the skin on the underside of your child’s forearm. After two or three days, we check the skin. If a certain kind of bump has developed, the test may be positive for TB infection. This means that your child:

  • may have TB infection
  • will need additional tests such as a chest x-ray and sputum test
  • may need to take medication

It does not mean your child can spread TB germs to others.

QFT Gold test

The QuantiFERON-TB Gold (QFT) test is a blood test that can determine if your child has been infected with TB. With this test, your child only needs to visit the doctor once, to have some blood drawn. You are then notified when the results become available, which can be as soon as the next day.

Other tests that may be used to confirm a diagnosis of TB include:

How is TB treated?

TB infection

Your child will need to take medicine to keep his infection from developing into TB disease. The most common medicine used for this is called Isoniazid (INH). It normally takes six to nine months for the medicine to kill the TB germs.

TB disease

If your child has TB disease, he will need to take several different medicines. This is because there are a lot of germs to be killed. Taking several medicines will do a better job of killing all of the germs and preventing them from becoming resistant to the medicines.

The most common medicines used to cure TB disease are:

  • isoniazid (INH)
  • rifampin (RIF)
  • ethambutol
  • pyrazinamide

How we care for tuberculosis

The Tuberculosis Program at Boston Children's Hospital cares for more than 400 TB-infected children each year. Located on the fourth floor of the Farley Building, our program provides comprehensive services ranging from evaluation and diagnosis to treatment and patient education.

Tuberculosis (TB) | Frequently Asked Questions

What are the dangerous side effects of medicines for TB?

The side effects listed below are serious. If your child has any of these symptoms, call your doctor immediately:

Why is the course of treatment so long?

The course of treatment is long because TB bacteria die very slowly — it takes at least six months for the medicine to kill all the TB germs in your child's body. We understand that no one likes long courses of treatment — whether you're taking or administering — but it's absolutely necessary that it be completed fully.

What happens if my child stops taking his medicine or doesn't take it regularly?

It is very important that your child takes his or her medicine the way your doctor or nurse has prescribed it. Otherwise, there are two serious dangers:

  • The TB bacteria will start to grow again and your child will stay sick or get worse.
  • The bacteria may become resistant to the medications your child is taking. Your child may need new, different medicines to kill the TB bacteria if the old medicines no longer work. These new medicines must be taken for a longer time and usually have more serious side effects.

What if my child starts feeling better sooner?

Your child will probably start feeling well after only a few weeks of treatment. But the TB bacteria are still alive. Your child must continue to take his medicine regularly until all the TB bacteria are dead.

What happens if my child forgets to take their medicine?

If your child forgets to take their pills one day, skip that dose and have him take the next scheduled dose. Notify your doctor or nurse when this occurs.

How can I keep my child from spreading TB?

The single most important thing is to make sure your child takes all of his medicine, exactly as directed.

You also need to attend all of your follow-up clinic appointments, so your doctor or nurse can see how your child is doing.

Also, make sure your child:

  • always covers his mouth with a tissue when he coughs, sneezes, or laughs.
  • put tissues in a closed bag and throws it away
  • stays home from school
  • avoids close contact with others
  • sleeps in a bedroom away from other family members
  • airs out his room (TB spreads in small closed spaces where air doesn't move)

Remember, TB is spread through the air. People cannot get infected with TB bacteria through handshakes, sitting on toilet seats, or sharing dishes and utensils with someone who has TB.

What is multidrug-resistant TB (MDR TB)?

Sometimes TB bacteria become resistant to two or more of the most important medicines: INH and RIF. This is called multidrug-resistant TB, or MDR TB. This is a serious problem.

If your child has MDR TB disease, he must be treated with special medicines. These medicines are not as good as the usual medicines for TB and may cause more side effects. Also, he will probably need to see a TB expert who can closely observe his treatment to make sure it is working.

If you have spent time with someone sick with MDR TB disease, you may become infected with these multidrug-resistant bacteria. If you have a positive skin test reaction, you may be given medicine to keep from developing MDR TB disease.

Tuberculosis (TB) | Programs & Services