Tuberculosis (TB), who don't know this disease? everyone knows,
because this disease strike anyone even it's children or adult. So, what is TB?
Tuberculosis (TB) is caused by a bacterium called
Mycobacterium tuberculosis. The bacteria usually attack the lungs, but TB
bacteria can attack any part of the body such as the kidney, spine, and brain.
If not treated properly, TB disease can be fatal.
TB is spread through the air from one person to another. The
TB bacteria are put into the air when a person with TB disease of the lungs or
throat coughs, sneezes, speaks, or sings. People nearby may breathe in these
bacteria and become infected.
TB is NOT spread by
1. shaking someone's hand
2. sharing food or drink
3. touching bed linens or toilet seats
4. sharing toothbrushes
5. kissing
Not everyone infected with TB bacteria becomes sick. As a
result, two TB-related conditions exist: latent TB infection and TB disease.
1. Latent TB Infection
TB bacteria can live in the body without making you sick.
This is called latent TB infection. In most people who breathe in TB bacteria
and become infected, the body is able to fight the bacteria to stop them from
growing. People with latent TB infection do not feel sick and do not have any
symptoms. People with latent TB infection are not infectious and cannot spread
TB bacteria to others. However, if TB bacteria become active in the body and
multiply, the person will go from having latent TB infection to being sick with
TB disease.
2. TB Disease
TB bacteria become active if the immune system can't stop
them from growing. When TB bacteria are active (multiplying in your body), this
is called TB disease. People with TB disease are sick. They may also be able to
spread the bacteria to people they spend time with every day.
Many people who have latent TB infection never develop TB
disease. Some people develop TB disease soon after becoming infected (within
weeks) before their immune system can fight the TB bacteria. Other people may
get sick years later when their immune system becomes weak for another reason. For
people whose immune systems are weak, especially those with HIV infection, the
risk of developing TB disease is much higher than for people with normal immune
systems.
There are two kinds of tests that are used to determine if a
person has been infected with TB bacteria: the tuberculin skin test and TB
blood tests.
A positive TB skin test or TB blood test only tells that a
person has been infected with TB bacteria. It does not tell whether the person
has latent TB infection (LTBI) or 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.
Nurse reading a patient's skin testTuberculin skin test: The
TB skin test (also called 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 health care worker will look for a raised, hard area or
swelling, and if present, measure its size using a ruler. Redness by itself is
not considered part of the reaction.
The skin test result depends on the size of the raised, hard
area or swelling. It also depends on the person’s risk of being infected with TB bacteria and the
progression to TB disease if infected.
Positive skin test: This means the person’s body was infected with TB bacteria. Additional
tests are needed to determine if the person has latent TB infection or TB
disease. A health care worker will then provide treatment as needed.
Negative skin test: This means the person’s body did not react to the test, and that latent TB
infection or TB disease is not likely.
Person holding a vial of blood TB blood tests: TB blood
tests (also called interferon-gamma release assays or IGRAs) measure how the
immune system reacts to the bacteria that cause TB. An IGRA measures how strong
a person’s immune system reacts to TB
bacteria by testing the person’s
blood in a laboratory.
Two IGRAs are approved by the U.S. Food and Drug
Administration (FDA) and are available in the United States:
• Positive IGRA: This means that the person has been infected
with TB bacteria. Additional tests are needed to determine if the person has
latent TB infection or TB disease. A health care worker will then provide
treatment as needed.
• Negative IGRA: This means that the person’s blood did not react to the test and that latent TB
infection or TB disease is not likely.
IGRAs are the preferred method of TB infection testing for
the following:
People who have received bacille Calmette–Guérin
(BCG). BCG is a vaccine for TB disease.
People who have a difficult time returning for a second
appointment to look for a reaction to the TST.
There is no problem with repeated IGRA.
TB tests are generally not needed for people with a low risk
of infection with TB bacteria. Certain people should be tested for TB bacteria
because they are more likely to get TB disease, including:
1. People who have spent time with someone who has TB
disease
2. People with HIV infection or another medical problem that
weakens the immune system
3. People who have symptoms of TB disease (fever, night
sweats, cough, and weight loss)
4. People from a country where TB disease is common (most
countries in Latin America, the Caribbean, Africa, Asia, Eastern Europe, and
Russia)
5. People who live or work somewhere in the United States
where TB disease is more common (homeless shelters, prison or jails, or some
nursing homes)
6. People who use illegal drugs
check this video to know more about TB
Symptoms and Spread of Tuberculosis:
[SCOME EXIST]
