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What is tuberculosis?
Tuberculosis (TB) is an infection caused by slow-growing bacteria that grow best in areas of the body that have lots of blood and oxygen. That's why it is most often found in the lungs. This is called pulmonary TB. But TB can also spread to other parts of the body, which is called extrapulmonary TB . Treatment is often a success, but it is a long process. It usually takes about 6 to 9 months to treat TB. But some TB infections need up to 2 years to treat.
Tuberculosis is either latent or active.
How is TB spread to others?
Pulmonary TB (in the lungs) is contagious. It spreads when a person who has active TB breathes out air that has the TB bacteria in it and then another person breathes in the bacteria from the air. An infected person releases even more bacteria when he or she does things like cough or laugh.
If TB is only in other parts of the body (extrapulmonary TB), it does not spread easily to others.
Who is most at risk for TB?
Some people are more likely than others to get TB. This includes people who:
It is important for people who are at a high risk for getting TB to get tested once or twice every year.
What are the symptoms?
Most of the time when people are first infected with TB, the disease is so mild that they don't even know they have it. People with latent TB don't have symptoms unless the disease becomes active.
Symptoms of active TB may include:
How is TB diagnosed?
Doctors usually find latent TB by doing a tuberculin skin test. During the skin test, a doctor or nurse will inject TB antigens under your skin. If you have TB bacteria in your body, within 2 days you will get a red bump where the needle went into your skin. The test can't tell when you became infected with TB or if it can be spread to others.
To find pulmonary TB, doctors test a sample of mucus from the lungs (sputum) to see if there are TB bacteria in it. Doctors sometimes do other tests on sputum and blood or take a chest X-ray to help find pulmonary TB.
How is it treated?
Most of the time, doctors combine four antibiotics to treat active TB. It's important to take the medicine for active TB for at least 6 months. Almost all people are cured if they take their medicine just like their doctors say to take it. If tests still show an active TB infection after 6 months, then treatment continues for another 2 or 3 months.
People with latent TB may be treated with one antibiotic that they take daily for 9 months or with a combination of antibiotics that they take once a week for 12 weeks while being watched by a health professional. Making sure every dose is taken reduces their risk for getting active TB.
If you miss doses of your medicine, or if you stop taking your medicine too soon, your treatment may fail or have to go on longer. You may have to start your treatment over again. This can also cause the infection to get worse or may lead to an infection that is resistant to antibiotics . This is much harder to treat.
TB can only be cured if you take all the doses of your medicine. A doctor or nurse may have to watch you take it to make sure that you never miss a dose and that you take it the proper way. You may have to go to the doctor's office every day. Or a nurse may come to your home or work. This is called direct observational treatment. It helps people follow all of the instructions and keep up with their treatment, which can be complex and take a long time. Cure rates for TB have greatly improved because of this type of treatment.
If active TB is not treated, it can damage your lungs or other organs and can be deadly. You can also spread TB by not treating an active TB infection.
Frequently Asked Questions
Tuberculosis (TB) is caused by Mycobacterium tuberculosis, slow-growing bacteria that thrive in areas of the body that are rich in blood and oxygen, such as the lungs.
If you have latent tuberculosis (TB), you do not have symptoms and cannot spread the disease to others. If you have active TB, you do have symptoms and can spread the disease to others. Which specific symptoms you have will depend on whether your TB infection is in your lungs (the most common site) or in another part of your body (extrapulmonary TB).
There are other conditions with symptoms similar to TB, such as pneumonia and lung cancer.
Symptoms of active TB in the lungs
Symptoms of active TB in the lungs begin gradually and develop over a period of weeks or months. You may have one or two mild symptoms and not even know that you have the disease.
Common symptoms include:
Symptoms of an active TB infection outside the lungs
Symptoms of TB outside the lungs (extrapulmonary TB) vary widely depending on which area of the body is infected. For example, back pain can be a symptom of TB in the spine, or your neck may get swollen when lymph nodes in the neck are infected.
Tuberculosis (TB) develops when Mycobacterium tuberculosis bacteria are inhaled into the lungs. The infection usually stays in the lungs. But the bacteria can travel through the bloodstream to other parts of the body (extrapulmonary TB).
An initial (primary) infection can be so mild that you don't even know you have an infection. In a person who has a healthy immune system, the body usually fights the infection by walling off (encapsulating) the bacteria into tiny capsules called tubercles. The bacteria remain alive but cannot spread to surrounding tissues or other people. This stage is called latent TB, and most people never go beyond it.
A reaction to a tuberculin skin test is how most people find out they have latent TB. It takes about 48 hours after the test for a reaction to develop, which is usually a red bump where the needle went into the skin. Or you could have a rapid blood test that provides results in about 24 hours.
If a person's immune system becomes unable to prevent the bacteria from growing, the TB becomes active. Of people who have latent TB, 5% (1 person out of 20) will develop active TB within 2 years after the initial infection. Another 5% of people who have latent TB will develop active TB at some point in their lives. 1
Active TB in the lungs
Active TB in the lungs (pulmonary TB) is contagious. TB spreads when a person who has active disease exhales air that contains TB-causing bacteria and another person inhales the bacteria from the air. These bacteria can remain floating in the air for several hours. Coughing, sneezing, laughing, or singing releases more bacteria than breathing.
In general, after 2 weeks of treatment with antibiotics, you cannot spread an active pulmonary TB infection to other people.
Skipping doses of medicine can delay a cure and cause a relapse. In these cases, you may need to start treatment over. Relapses usually occur within 6 to 12 months after treatment. Not taking the full course of treatment also allows antibiotic-resistant strains of the bacteria to develop, making treatment more difficult.
Without treatment, active TB can cause serious complications, such as:
TB can be fatal if it is not treated.
Active TB outside the lungs
Active TB in parts of the body other than the lungs (extrapulmonary TB) is not spread easily to other people. You take the same medicines that are used to treat pulmonary TB. You may need other treatments depending on where in your body the infection is growing and how severe it is.
TB in certain groups of people
Infants and children and people with HIV or AIDS who have active TB need special care.
What Increases Your Risk
People are at increased risk of infection with tuberculosis (TB) when they:
People who have an infection that cannot spread to others (latent TB infection) are at risk of developing active TB if they:
When To Call a Doctor
Call your doctor immediately if you have:
Call your doctor if you:
Who to see
Health professionals and public health agencies can help you discover whether you have tuberculosis (TB). These include:
Health professionals and public health agencies can also help you with treatment. They include:
If you have multidrug-resistant TB, you may need to go to a hospital that specializes in treating this type of TB.
To prepare for your appointment, see the topic Making the Most of Your Appointment.
Exams and Tests
Diagnosing active TB in the lungs
Doctors diagnose active tuberculosis (TB) in the lungs (pulmonary TB) by using a medical history and physical exam, and by checking your symptoms (such as an ongoing cough, fatigue, fever, or night sweats). Doctors will also look at the results of a:
Diagnosing latent TB in the lungs
Diagnosing TB outside the lungs
Diagnosing TB in other parts of the body (extrapulmonary TB) requires more testing. Tests include:
Tests during TB treatment
During treatment, a sputum culture is done once a month—or more often—to make sure that the antibiotics are working. You may have a chest X-ray at the end of treatment to use as a comparison in the future.
You may have tests to see if TB medicines are harming other parts of your body. These tests may include:
Public health officials encourage early testing for people who are at risk for getting TB.
Doctors treat tuberculosis (TB) with antibiotics to kill the TB bacteria. These medicines are given to everyone who has TB, including infants, children, pregnant women, and people who have a weakened immune system .
Treatment for active tuberculosis
Health experts recommend: 4
Treatment for latent tuberculosis
Experts recommend one of the following:
Treatment is recommended for anyone with a skin test that shows a TB infection, and is especially important for people who:
Treatment for extrapulmonary tuberculosis
Treatment for tuberculosis in parts of the body other than the lungs (extrapulmonary TB) usually is the same as for pulmonary TB. You may need other medicines or forms of treatment depending on where the infection is in the body and whether complications develop.
You may need treatment in a hospital if you have:
What to think about
If treatment is not successful, the TB infection can flare up again (relapse). People who have relapses usually have them within 6 to 12 months after treatment. Treatment for relapse is based on the severity of the disease and which medicines were used during the first treatment.
Active tuberculosis (TB) is very contagious. The World Health Organization (WHO) estimates that one-third of the world's population is infected with the bacteria that cause TB.
To avoid getting an active TB infection:
Can the TB vaccine help?
A TB vaccine ( bacille Calmette-Guerin , or BCG) is used in many countries to prevent TB. But this vaccination is almost never used in the United States because:
Home treatment for tuberculosis (TB) focuses on taking the medicines correctly to reduce the risk of developing multidrug-resistant TB.
Healthy eating and exercise
During treatment for TB, eat healthy foods and get enough sleep and some exercise to help your body fight the infection.
If you are losing too much weight, eat balanced meals with enough protein and calories to help you keep weight on. If you need help, ask to talk with a registered dietitian .
Because TB treatment takes so long, you may have trouble coping.
Your doctor or health department can help you find a counselor or social worker to help you cope with your feelings. If you cannot afford counseling or treatment, there may be places that offer free or less costly help.
Active tuberculosis (TB)
Several antibiotics are used at the same time to treat active tuberculosis (TB) disease. For people who have multidrug-resistant TB, treatment may continue for as long as 24 months. These antibiotics are given as pills or injections.
For active TB, there are different treatment recommendations for people who have HIV and TB, people who have drug-resistant TB, children, and pregnant women.
TB disease that occurs in parts of your body other than the lungs (extrapulmonary TB) usually is treated with the same medicines and for the same length of time as active TB in the lungs (pulmonary TB). But TB throughout the body (miliary TB) or TB that affects the brain or the bones and joints in children may be treated for at least 12 months.
Corticosteroid medicines also may be given in some severe cases to reduce inflammation. They may be helpful for children at risk of central nervous system problems caused by TB and for people who have conditions such as high fever, TB throughout the body (miliary TB), pericarditis , or peritonitis .
One antibiotic usually is used to treat latent TB infection, which cannot be spread to others but can develop into active TB disease. The antibiotic usually is taken for 4 to 9 months. 1 Or more than one antibiotic may be taken once a week for 12 weeks. 5 For this treatment, a health professional watches you take each dose of antibiotics. Taking every dose of antibiotic helps prevent the TB bacteria from getting resistant to the antibiotics.
Multiple-drug therapy to treat TB usually involves taking four antibiotics at the same time. This is the standard treatment for active TB.
What to think about
If you miss doses of medicine or you stop treatment too soon, your treatment may go on longer or you may have to start over. This can also cause the infection to get worse, or it may lead to antibiotic-resistant infections that are much harder to treat.
Taking all of the medicines is especially important for people who have an impaired immune system. They may be at an increased risk for a relapse because the original TB infection was never cured.
Surgery is rarely used to treat tuberculosis (TB). But it may be used to treat extensively drug-resistant TB (XDR-TB) or to treat complications of an infection in the lungs or another part of the body.
Surgery is used to:
Surgery has a high success rate, but it also has a risk of complications, which may include infections other than TB and shortness of breath after surgery.
Surgery for TB outside the lungs
Surgery sometimes may be needed to remove or repair organs damaged by TB in parts of the body other than the lungs (extrapulmonary TB) or to prevent other rare complications, such as:
Other Places To Get Help
Last Revised: February 7, 2012
Sharma SK, Mohan A (2009). Tuberculosis and other mycobacterial diseases. In RE Rakel, ET Bope, eds., Conn's Current Therapy 2009. pp. 282–290. Philadelphia: Saunders Elsevier.
Ludvigsson JF, et al. (2007). Coeliac disease and risk of tuberculosis: A population based cohort study. Thorax, 62(1): 23–28.
Centers for Disease Control and Prevention (2005). Guidelines for using the QuantiFERON®-TB test for diagnosing latent Mycobacterium tuberculosis infection. MMWR, 54(RR-15): 49–55.
American Thoracic Society, Centers for Disease Control and Prevention, Infectious Diseases Society of America (2003). Treatment of tuberculosis. American Journal of Respiratory and Critical Care Medicine, 167(4): 603–662.
U.S. Centers for Disease Control and Prevention (2011). Recommendations for use of an isoniazid-rifapentine regimen with direct observation to treat latent Mycobacterium tuberculosis infection. MMWR, 60(48): 1650–1653. Available online: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6048a3.htm.
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