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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 to be treated for up to 2 years.
Tuberculosis is either latent or active.
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
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.
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
Symptoms of active TB may include:
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. A blood test also can be done to look for TB.
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.
extrapulmonary TB, doctors can take a sample of tissue (biopsy) to test. Or you might get a
CT scan or an
MRI so the doctor can see pictures of the inside of
Most of the time, doctors
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. If the TB bacteria are resistant to several antibiotics (multidrug-resistant TB), then treatment may be needed for a year or longer.
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
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
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.
Learning about tuberculosis (TB):
Living with 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.
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
Common symptoms include:
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
lymph nodes in the neck are infected.
(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
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%
to 10% (1 to 2 people out of 20) will develop active TB at
some point in their lives.1
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
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.
active TB can cause serious complications, such as:
TB can be fatal if it is not treated.
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.
Infants and children and people with
HIV or AIDS who have active TB need special care.
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:
Call your doctor immediately if you have:
Call your doctor if you:
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 (MDR-TB), you may need to go to a
special treatment center that treats this type of TB.
To prepare for your appointment, see the topic Making the Most of Your Appointment.
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 TB in
other parts of the body (extrapulmonary TB) requires more
testing. Tests include:
HIV infection is often done at the time of TB
diagnosis. You may also have a blood test for
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
Public health officials encourage
screening for people who are at risk for getting TB.
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.
Health experts recommend:4
Experts recommend one of the following:
recommended for anyone with a skin test that shows a TB infection, and is
especially important for people who:
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
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.
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.
getting an active TB infection:
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
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
Because TB treatment takes so
long, it is normal to:
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
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 children, pregnant women, people who have HIV and TB, and people who have
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.
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),
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
Other anti-tuberculosis medicines may be used for people with multidrug-resistant TB.
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
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 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.
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:
Pasipanodya J, et al. (2011). Tuberculosis and other
mycobacterial diseases. In ET Bope et al., eds., Conn's Current Therapy 2011. pp. 295–301. Philadelphia: Saunders.
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.
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?s_cid=mm6048a3_w.
Other Works Consulted
Akolo C, et al. (2010). Treatment of latent
tuberculosis infection in HIV infected persons. Cochrane Database of Systematic Reviews (1).
Centers for Disease Control and Prevention (2012).
Reported Tuberculosis in the United States, 2011.
Atlanta: U.S. Department of Health and Human Services. Also available online: http://www.cdc.gov/tb/statistics/reports/2011/default.htm.
U.S. Centers for Disease Control and Prevention (2010). Updated guidelines for using interferon gamma release assays to detect Mycobacterium tuberculosis infection—United States, 2010. MMWR, 59(RR-05): 1–25. Available online: http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5905a1.htm?s_cid=rr5905a1_e.
World Health Organization (2011). Guidelines for intensified tuberculosis case-finding and isoniazid preventive therapy for people living with HIV in resource-constrained settings. Available online: http://www.who.int/hiv/pub/tb/9789241500708/en.
World Health Organization (2011). Guidelines for the programmatic management of drug-resistant tuberculosis: 2011 update. European Respiratory Journal, 38(3): 516–528.
Ziganshina LA, Eisenhut M (2011). Tuberculosis (HIV-negative people), search
date July 2010. BMJ Clinical Evidence. Available online: http://www.clinicalevidence.com.
April 4, 2013
E. Gregory Thompson, MD - Internal Medicine & R. Steven Tharratt, MD, MPVM, FACP, FCCP - Pulmonology, Critical Care Medicine, Medical Toxicology
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