What is tuberculosis?

Tuberculosis (TB) is a chronic bacterial infection that usually infects the lungs, although other organs such as the kidneys, spine, or brain are sometimes involved. TB is primarily an airborne disease.

There is a difference between being infected with the TB bacterium and having active tuberculosis disease.

There are three important ways to describe the stages of TB. They are as follows:

• Exposure. This occurs when a person has been in contact with, or exposed to, another person who is thought to have or does have TB. The exposed person will have a negative skin test, a normal chest X-ray, and no symptoms of the disease.

• Latent TB infection. This occurs when a person has TB bacteria in his or her body, but does not have symptoms of the disease. The infected person's immune system walls off the TB organisms and they remain dormant throughout life in most people who are infected. This person would have a positive skin test but a normal chest X-ray.

• TB disease. This describes the person who has signs and symptoms of an active infection. This person would have a positive skin test and a positive chest X-ray.

The predominant TB bacterium is Mycobacterium tuberculosis (M. tuberculosis). Many people infected with M. tuberculosis never develop active TB and remain in the latent TB stage. However, in people with weakened immune systems, including those with HIV (human immunodeficiency virus) or diabetes, and those who are treated with medications that can weaken the immune system, such as corticosteroids and chemotherapy, TB organisms can overcome the body's defenses, multiply, and cause an active disease. Very young children are more likely than older children and adults to have TB spread through their bloodstream and cause complications, such as meningitis.

Who is at risk for developing TB?

TB affects all ages, races, income levels, and both genders. Those at higher risk include the following:

• People who live or work with others who have TB

• Medically underserved populations

• Homeless people

• People from other countries where TB is prevalent

• People in group settings, such as nursing homes

• People who abuse alcohol

• People who use intravenous drugs

• People with impaired immune systems

• The elderly

• Healthcare workers who come in contact with high-risk populations

What are the symptoms of TB?

Different symptoms of TB are present depending on the age of the child affected. The following are the most common symptoms of active TB. However, each child may experience symptoms differently. Symptoms may include:

• In children:

  • Fever

  • Unintended weight loss

  • Poor growth

  • Sweating at night

  • Cough

  • Swollen glands

  • Chills

• In adolescents:

  • Cough that lasts longer than three weeks

  • Productive cough

  • Pain in the chest

  • Blood in their sputum

  • Weakness and fatigue

  • Swollen glands

  • Unintended weight loss

  • Decrease in appetite

  • Fever

  • Chills or night sweats

The symptoms of TB may resemble other lung conditions or medical problems. Always consult your child's doctor for a diagnosis.

What causes TB?

The TB bacterium is spread through the air when an infected person coughs, sneezes, speaks, sings, or laughs; however, repeated exposure to the germs is usually necessary before a person will become infected. It is not likely to be transmitted through personal items, such as clothing, bedding, a drinking glass, eating utensils, a handshake, a toilet, or other items that a person with TB has touched. Adequate ventilation is the most important measure to prevent the transmission of TB.

How is TB diagnosed?

TB is diagnosed with a TB skin test. In this test, a small amount of testing material is injected into the top layer of the skin. If a certain size bump develops within two or three days, the test may be positive for tuberculosis infection. Additional tests to determine if a child has TB disease include X-rays and sputum tests. There are also blood tests called interferon-gamma release assays that can aid in diagnosing Mycobacterium tuberculosis.  

TB skin tests are suggested for those:

• In high-risk categories.

• Who live or work in close contact with people who are at high risk.

• Who have never had a TB skin test.

For skin testing in children, the American Academy of Pediatrics recommends:

Immediate testing:

• If the child is thought to have been exposed in the last five years.

• If the child has an X-ray that looks like TB.

• If the child has any symptoms of TB.

• If the child comes from a country where TB is prevalent.

Yearly skin testing:

• For children with HIV.

• For children who are in detention facilities.

Testing every 2 to 3 years:

• For children who are exposed to high-risk people.

Consider testing in children from ages 4 to 6 and 11 to 16:

• If the child's parent has come from a high-risk country.

• If the child has traveled to high-risk areas.

• If the child lives in a densely-populated area.

What is the treatment for tuberculosis?

Specific treatment will be determined by your child's doctor based on:

• His or her age, overall health, and medical history

• Extent of the disease

• His or her tolerance for specific medications, procedures, or therapies

• Expectations for the course of the disease

• Your opinion or preference

Treatment may include:

• Short-term hospitalization

• Medications

• For latent TB in children ages 2 to 11. Usually a six- to 12-month course of isoniazid will be given to kill off the TB organisms in the body.

• For active TB in children. Doctors may prescribe three to four medications at once including isoniazid, rifampin, pyrazinamide, or streptomycin for a period of time up to six months or more for the medication to be effective.  

Patients usually begin to improve within a few weeks of the start of treatment. After two weeks of treatment with the correct medications, the patient is not usually contagious, provided that treatment is carried through to the end, as prescribed by a doctor.

Learn more about TB and the TB vaccine at CHOP's Vaccine Education Center.