Tuberculosis (TB)

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.

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

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.

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

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.

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.

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.

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:

• Comprehensive history and physical exam
• Chest X-ray
• Computerized tomography (CT) scan
• Bronchoscopy
• Sputum analysis

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

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.