Tuberculosis: General Information
||Tuberculosis: General Information
What is TB?
Tuberculosis (TB) is a disease caused by germs that are spread
from person to person through the air. TB usually affects the
lungs, but it can also affect other parts of the body, such as
the brain, the kidneys, or the spine. A person with TB can die
if they do not get treatment.
What Are the Symptoms of TB?
The general symptoms of TB disease include feelings of sickness
or weakness, weight loss, fever, and night sweats. The symptoms
of TB disease of the lungs also include coughing, chest pain,
and the coughing up of blood. Symptoms of TB disease in other
parts of the body depend on the area affected.
How is TB Spread?
TB germs are put into the air when a person with TB disease
of the lungs or throat coughs, sneezes, speaks, or sings. These
germs can stay in the air for several hours, depending on the
environment. Persons who breathe in the air containing these TB
germs can become infected; this is called latent TB infection.
What is the Difference Between Latent TB Infection and TB Disease?
People with latent TB infection have TB germs in their
bodies, but they are not sick because the germs are not active.
These people do not have symptoms of TB disease, and they cannot
spread the germs to others. However, they may develop TB disease
in the future. They are often prescribed treatment to prevent
them from developing TB disease.
People with TB disease are sick from TB germs that are active,
meaning that they are multiplying and destroying tissue in their
body. They usually have symptoms of TB disease. People with TB
disease of the lungs or throat are capable of spreading germs
to others. They are prescribed drugs that can
treat TB disease.
What Should I Do If I Have Spent Time with Someone with Latent
A person with latent TB infection cannot spread germs to other
people. You do not need to be tested if you have spent time with
someone with latent TB infection. However, if you have spent time
with someone with TB disease or someone with symptoms of TB, you
should be tested.
What Should I Do if I Have Been Exposed to Someone with TB
People with TB disease are most likely to spread the germs to
people they spend time with every day, such as family members
or coworkers. If you have been around someone who
has TB disease, you should go to your doctor or your local health
department for tests.
How Do You Get Tested for TB?
There are two tests that can be used to help detect TB infection: a skin test or a special TB blood test. The
Mantoux tuberculin skin test is performed by injecting a small amount of fluid (called tuberculin) into the skin
in the lower part of the arm. A person given the tuberculin skin test must
return within 48 to 72 hours to have a trained health care worker look for a reaction on the arm. The special TB blood test measures how the
patient’s immune system reacts to the germs that cause TB.
What Does a Positive Test for TB Infection
A positive test for TB infection only tells that a person has been infected with TB germs. It does not tell whether or not the person has progressed to TB disease. Other tests, such as a chest x-ray and a
sample of sputum, are needed to see whether the person has TB disease.
What is Bacille Calmette-Guérin (BCG)?
BCG is a vaccine for TB disease. BCG is used in many countries,
but it is not generally recommended in the United States. BCG
vaccination does not completely prevent people from getting TB.
It may also cause a false positive tuberculin skin test. However,
persons who have been vaccinated with BCG can be given a tuberculin
skin test or QuantiFERON®-TB Gold test.
Why is Latent TB Infection Treated?
If you have latent TB infection but not TB disease, your doctor
may want you to take a drug to kill the TB germs and prevent you
from developing TB disease. The decision about taking treatment
for latent infection will be based on your chances of developing
TB disease. Some people are more likely than others to develop
TB disease once they have TB infection. This includes people with
HIV infection, people who were recently exposed to someone with
TB disease, and people with certain medical conditions.
How is TB Disease Treated?
TB disease can be treated by taking several drugs for 6 to 12 months.
It is very important that people who have TB disease finish the
medicine, and take the drugs exactly as prescribed. If they stop
taking the drugs too soon, they can become sick again; if they
do not take the drugs correctly, the germs that are still alive
may become resistant to those drugs. TB that is resistant to drugs
is harder and more expensive to treat. In some situations, staff
of the local health department meet regularly with patients who
have TB to watch them take their medications. This is called directly
observed therapy (DOT). DOT helps the patient complete treatment
in the least amount of time.
CDC. Questions and Answers
About TB (2007).