What is TB?
Tuberculosis, or TB, can be a chronic bacterial infection that usually infects the lungs. Other organs, such as the kidneys, spine, or brain may also be involved. TB is primarily spread from person to person in an airborne manner, such as when an infected person coughs or sneezes. It can also cause an active infection after a period of dormancy in someone who was exposed at an earlier time.
There is a difference between being infected with the TB bacterium and having active tuberculosis disease.
The following are the stages of TB:
- 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 signs or 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 the TB remains 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. The person would have a positive skin test and a positive chest X-ray.
What causes TB?
The main TB bacterium is Mycobacterium tuberculosis (M. tuberculosis). Many people infected with this bacterium never develop active TB. They remain in the latent TB stage. However, in people with weak immune systems, especially those with HIV (human immunodeficiency virus), TB organisms can overcome the body's defenses, multiply, and cause an active disease.
The TB bacterium is spread through the air when an infected person coughs, sneezes, speaks, sings, or laughs. It’s not likely to be spread 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. Good ventilation is the most important measure to prevent the transmission of TB.
Who is at risk for 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
- Those who can’t access health care
- 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 weak immune systems
- The elderly
- Health care workers who come in contact with high-risk populations
What are the symptoms of TB?
The following are the most common symptoms of active TB. However, each person may experience symptoms differently:
- Cough that will not go away
- Chest pain
- Loss of appetite
- Unintended weight loss
- Poor growth in children
- Coughing blood or sputum
- Chills or night sweats
The symptoms of TB may look like other lung conditions or medical problems. Consult a health care provider for a diagnosis.
How is TB diagnosed?
TB is often diagnosed with a 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 2 or 3 days, the test may be positive for tuberculosis infection. Other tests include X-rays and sputum tests. A blood test can be done in place of the TB skin test.
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 testing:
- If the child is thought to have been exposed in the last 5 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
- For children with HIV
- For children who are in detention facilities
- For children who are exposed to high-risk people
- 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
How is TB treated?
Specific treatment will be determined by your health care provider based on:
- Your age, overall health, and medical history
- Extent of the disease
- Your tolerance for specific medications, procedures, or therapies
- Expectations for the course of the disease
- Your opinion or preference
Treatment may include:
- Short-term hospitalization
- For latent TB which is newly diagnosed: Usually a 6 to 12 month course of antibiotic called isoniazid will be given to kill off the TB organisms in the body.
- For active TB: Your health care provider may prescribe 3 or more antibiotics in combination for 6 to 9 months or longer. Examples include: isoniazid, rifampin, pyrazinamide, and ethambutol. People usually begin to improve within a few weeks of the start of treatment. After several weeks of treatment with the correct medications, the person is usually no longer contagious, if treatment is carried through to the end, as prescribed by a health care provider.
What are the complications of TB?
If TB is not treated early or if treatment isn’t followed, lung damage can occur.
Can TB be prevented?
If you will be spending time with a person or people with active TB, wear a facemask and try not to stay in a small enclosed space with poor ventilation. People who work in situations where there is a high risk for encountering people infected with TB, such as health care workers, should be tested for TB on a routine basis.
When should I call my health care provider?
If your symptoms get worse or you get new symptoms, let your health care provider know.
Key points about TB
- Tuberculosis can be a chronic bacterial infection that usually infects the lungs.
- It may also affect the kidneys, spine, and brain.
- Being infected with the TB bacterium is not the same as having active tuberculosis disease.
- There are 3 stages of TB: exposure, latent, and active disease.
- A TB skin test can diagnose the disease before symptoms begin.
- Treatment is required to cure the disease and prevent its spread to other people.
Tips to help you get the most from a visit to your health care provider:
- Before your visit, write down questions you want answered.
- Bring someone with you to help you ask questions and remember what your provider tells you.
- At the visit, write down the names of new medicines, treatments, or tests, and any new instructions your provider gives you.
- If you have a follow-up appointment, write down the date, time, and purpose for that visit.
- Know how you can contact your provider if you have questions.
Online Medical Reviewer:
Foster, Sara, RN, MPH
Online Medical Reviewer:
Freeborn, Donna, PhD, CNM, FNP
Last Review Date:
© 2000-2017 The StayWell Company, LLC. 800 Township Line Road, Yardley, PA 19067. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.